A Very Long Primer on Record Cleaning Fluids


This primer discusses the chemistry and basic concepts behind record cleaning fluids (RCFs). Based on the positive response from another forum, I decided to make this primer available to Audiogon members as well. Such information is sadly missing from most RCF discussions which too often leave us still mystified or, far worse, misinformed. The alcohol scare is a good example of a resilient myth that is particularly misleading because it contains an element of truth. It is not my intention, however, to vilify or endorse specific commercial RCFs. I only hope that a better understanding of how these products work will enable you to select the right one for your need and use it in the safest and most effective way. I make no claim to be an expert on either RCF or Vinyl. The discussion below is based on my years of working in Surface Chemistry R & D and caring for my own LPs.

Note: If you loathe long technical discussions, feel free to proceed directly to the summary (section G) at the very end.

A. THE VINYL

LPs, also known as Vinyls, are made from an eponymous polymer (lower-case vinyl) also known as PVC (polyvinyl chloride). Like many thermoplastic materials, vinyl requires many additives during its manufacturing to give it the desired physical properties. These additives represent only a small portion of the overall formulation. Common additives include stabilizers (metals such as barium, calcium, cadmium, lead, zinc, etc.), colorants (dyes) and plasticizers (softeners).

Plasticizers are softening agents that give vinyl its low-temperature flexibility. They are of particular interest in record cleaning because, unlike stabilizers and dyes which are chemically bound to the polymer, plasticizers are simply mixed within the polymer matrix. The most common plasticizers are phthalate esters (derived from naphtha, a polyaromatic fraction of crude oil). Phthalates used in vinyl are large, polar molecules which have no significant vapor pressure (minimal loss by evaporation). They are, however, soluble in alcohol or surfactant solution (!). A loss of plasticizer renders vinyl brittle and susceptible to further mechanical damage.

B. THE CONTAMINANTS

Even a pristine Vinyl still sealed in its jacket is covered with a thin layer of mold release, a lubricant used to ease the removal of the record from its mold after stamping. The chemical composition of this mold release varies but it is traditionally a lubricant of medium molecular weight. Modern mold releases are polytetrafluoroethylene (PTFE or Teflon) in liquid or dry form.

Used Vinyls have a host of other contaminants which are less well defined. The most common contaminant is dust, on the Vinyl surface or imbedded in the Vinyl grooves. Dust can be of two origins: skin-cell debris and fine particles of dirt and sand. Other contaminants are finger prints (skin oil), adhesive (label glue), cigarette smoke and materials of unknown and sometimes surprising origins.

C. IDEAL PROPERTIES FOR RECORD-CLEANING FLUIDS

1. An RCF must be able to “wet” the Vinyl surface. Wetting ensures intimate contact between RFC and Vinyl without which cleaning is impossible. The fluid must have near zero contact angle on vinyl, i.e., it must “spread” on the vinyl surface rather than bead up. Most polar organic solvents such as alcohol and chlorofluoro alkane tend to wet vinyl. Water does not unless it contains a polar organic solvent or a surfactant—more familiar known as soap or detergent.

2. An RCF must “penetrate” tight spaces in the Vinyl groove to remove contaminants within those nooks and crannies. (analogy: dirt ground into a fabric is far more difficult to launder than surface dirt.) To squeeze through these micron-size spaces within the Vinyl grooves, an RFC must have low surface tensions, and the smaller the pores, the lower the tension required. (The surface tension is an indicator of how easily a liquid droplet can be deformed to squeeze through tight spaces). Thus, pure water with high surface tension is kept out of all tight spaces in the grooves. Alcohol, pure or diluted in water, has a moderate surface tension and cannot access the smallest pores. Water containing enough effective surfactant has a low surface tension and can access all areas.

3. An RCF must be able to “dissolve” contaminants on contact. Polar solvents like alcohols can; water cannot unless it contains alcohol or surfactant. Alcohol helps disperse contaminants in the water and its effectiveness varies with the type and amount of alcohol. A surfactant removes organic contaminants differently. At concentrations above the cmc (critical micellar concentration), surfactant molecules spontaneously aggregate into small spheres called micelles, each consisting of a few to a few hundred surfactant molecules. Within each micelle, the surfactant polar heads are aligned outward to form the polar surface the micelle that keeps it soluble in water. The surfactant hydrocarbon tails point inward to form the organic core that acts like a large expandable reservoir to “solubilize” contaminants. Note: The cmc of a typical surfactant in water ranges from about 0.01% to 0.25% by weight. Diluting a commercial RCF below its cmc will yield poor cleaning due to high tensions, poor solubilization and low foam. Consult the manufacturer for safe dilution. Below the cmc, a surfactant becomes merely a wetting agent.

4. An RCF must be able to “transport” contaminants away from the vinyl surface. Dissolved organic contaminants are transported within the bulk of the liquid itself (by dispersion or solubilization). Dust and other solid contaminants are carried away mostly by froth or foam (a processed called flotation). RCFs that are the best foamers are also the best dust removers. They are, in decreasing order of foamability: surfactant in water (best), alcohol in water and pure water (worst).

5. An RCF must not leave any “solid residue or thin film” behind after vacuuming. It is obvious that RCFs should contain as little solid residue as possible. But beyond that, all liquid components of the RCF should also be easily removed by vacuuming. While the bulk of RCF is vacuumed off the Vinyl surface, a small part of it is usually left behind as an “adsorption” film. How completely this very thin film is removed by vacuum depends on it volatility.

D. THE VITAL AND OVERLOOKED ROLE OF ADSORPTION FILM

Adsorption complicates matters in the removal of RCF from the Vinyl surface. Whenever a liquid (RCF) comes into contact with a solid surface (Vinyl), a fraction of the liquid’s component, be it alcohol, water or surfactant, will “adsorb” onto specific sites on the solid surface via electrical attraction and/or hydrogen bonding. Even after the bulk of the liquid has been removed by vacuum, a small fraction of the water, alcohol, surfactant and other RCF additives will always remains on the Vinyl surface as an adsorbed film consisting of several layers of molecules usually less than a micron thick. How this adsorbed film affects the integrity and sound of the Vinyl has hardly been addressed by RCF manufacturers.

If the adsorbed material is a highly volatile alcohol then it will quickly evaporate under vacuum before it has time to “leach” any significant amount of plasticizer. Adsorbed water does no harm to the Vinyl or the sound even if it remains on the Vinyl surface for a long time. On the other hand, surfactant (with water) or other additives adsorbed and left on the Vinyl surface after vacuuming may extract plasticizer, create static noises (like laundered clothes in the dryer), or alter the Vinyl sound (positively or negatively depending on the adsorbed material and your bias).

Recommendation: With water-based RCF, rinse the freshly cleaned Vinyl surface with distilled water to re-dissolve adsorbed materials and then re-vacuum the Vinyl surface to remove as much residual materials as possible.

E. FREQUENTLY ASKED QUESTIONS ABOUT RECORD CLEANING FLUIDS

E1. What are the Common Ingredients in Record Cleaning Fluids?

As you know by now, no single fluid makes an ideal RCF. Commercial RCFs usually combine different ingredients to maximize cleaning and minimize damage. There are three basic types of RCF.

1) Polar organic solvent(s). This could be a mixture of alcohols in water to form a broad-spectrum fluid, which is capable of dissolving a wide range of superficial contaminants. It could also be one or several organic solvents specifically formulated for deep cleaning of mold release and heavy organic contaminants.

2) Surfactant(s) in water to provide deep cleaning (by solubilization and flotation). It should be pointed out here that the effectiveness of a surfactant against a specific contaminant depends on the surfactant type, its molecular weight and structure. To tackle a broad range of contaminants, it is often necessary to blend several surfactants.

3) Mixtures of surfactant(s), alcohol(s) and other polar solvent(s) in water to tackle a range of contaminants broader than normally possible with a single surfactant or alcohol. Other components may also be added (lubricant, preservative, static suppressor) but they do not attend to the cleaning process.

I will spend the remainder of this primer discussing specific contaminants, specific RCF ingredients, how to recognize them when though they are not listed, their effectiveness and potential harm if improperly used, and special cleaning step(s) recommended with each type.

E2. Should I Remove Mold Release?

As previously stated, modern mold releases for Vinyl are polytetrafluoro-ethylene (PTFE or Teflon) liquid. The presence of fluorine makes this a tough contaminant to remove. Even pure alcohols have limited effect on mold releases. Organic solvents of the chlorofluorocarbon type (CFC similar to Freon but larger) work best on PTFE: they can quickly dissolve the mold release but not the plasticizer because of large differences in molecular structure and volatility. CFCs such as trichlorotrifluoro ethane were used to remove mold release until they were banned because of their adverse effects on the air and the ozone layer although it’s unclear whether larger and less volatile CFCs are as harmful as Freon.

Several commercial RCFs are “deep cleaners” that contain powerful organic solvent(s) and/or surfactant(s) in water. This type of deep cleaner will remove mold release and heavy contaminants, but, being less selective than CFCs, may remove plasticizer as well. Use this type of deep cleaner cautiously and sparingly as their cumulative effect on Vinyl is unknown. Some RCFs contains lubricant that compensates for plasticizer loss.

I am ambivalent about the need to remove mold release. On one hand, any organic material on Vinyl, even an exceedingly thin film, must be considered a contaminant and should be removed. On the other hand, mold releases are PTFE molecules, which are among the softest polymer extant, especially in comparison to vinyl. I seriously doubt that a thin film of such material could significantly affect Vinyl sound—I am in the realm of educated guess here.

E3. Leaching Plasticizers: How Bad Is Alcohol?

This is easily the most confusing and misunderstood topic about RCF. First let’s get one thing straight: old Shellac records are incredibly sensitive to all alcohols and none should be used on these precious old records, period.

Vinyl is not at all sensitive to alcohols but the plasticizer within the vinyl matrix is. Alcohols can slowly dissolve a plasticizer out of the vinyl thus rendering it brittle in the long run. This dissolution is, however, a slow process—the alcohol must first “wet” the vinyl surface, slowly “enter” the grooves via “film flow,” and finally “diffuse” into the vinyl matrix to dissolve the plasticizer. Each step depends a great deal on the polarity of the alcohol and its concentration. When an alcohol is diluted with a lot of water, it quickly loses its ability (polarity) to dissolve plasticizer. A mixture of 5 to 15% IPA in water has a limited ability if any to leach plasticizer especially when the contact time is restricted to a few minutes or less.

There are many legitimate reasons for using alcohol (or their mixture) as an RCF additive. 1) Alcohol leaves no film behind and thus has no sonic signature—this is a very desirable quality to some audiophiles. 2) Though inferior to surfactant, alcohol is still a good cleaner and will work adequately with new or moderately dirty records. It cannot remove deeply imbedded dirt or very sticky materials but it can handle a broader range of contaminants than a surfactant. 3) As long as the concentration of alcohol is low and the applied liquid quickly removed from the Vinyl surface with a powerful vacuum, an alcohol/water cleaner is perfectly safe.

E4. Are All Water-Based RCFs (with Surfactant) Equally Effective?

No. Let’s first review the likely surfactants used in water-based RCF. Though surfactants are generally effective cleaners, this effectiveness varies a great deal with the surfactant type (head), its molecular size and structure (tail), and the type of contaminant. Nonionic and anionic surfactants are typical surfactants used in RCF.

By far the most common nonionic surfactants are alkyl phenol ethoxylated alcohols. They naturally come as a broad mixture (Poisson distribution) of molecular weights and, for this reason, can accommodate a wide range of contaminants. For the same reason, they—more specifically one fraction of the nonionic mixture—can readily remove the plasticizer as well. Nonionic surfactants also tend to adsorb more on Vinyl surface.

Common anionic surfactants are alkyl sulfates, alkylethoxy sulfate, alkylaryl sulfonates and alkylarylethoxy sulfonates in roughly increasing order of detergency. 1) Alkyl sulfates are old laundry detergents, which tend to lose their effectiveness in cold water and in the presence of hardness (calcium). This shortcoming is rectified in synthetic alkylethoxy sulfates. 2) Alkyl- or alkyaryl sulfonates are good synthetic surfactants. However, their molecular structure must be tailored to the contaminants. Certain structures may form a viscous phase with contaminants which is difficult to remove. For record cleaning, they are more effective as a broad mixture. 3) Alkyl- or alkyarylethoxy sulfonates are one of the most powerful and versatile commercial surfactants. They work in hard water, accommodate a wide range of contaminants and are excellent foamers as well. Their effect on the plasticizer may be minimized with a careful selection of the molecular size. Finally, cationic surfactants traditionally used as fabric softener and hair conditioner may also be used as a static suppressor.

It should be noted that the surfactants used in most commercial RCF are fairly pedestrian cleaners commonly used in other household products. There is a plethora of sophisticated surfactants that are capable of doing a much better job of cleaning records with less potential harm. While some may be considerably more expensive that common surfactants, the added cost is not significant because of their low concentration. We have yet to enjoy state-of-the art surfactants in record cleaning fluids.

Note: The effectiveness and safety of commercial RCFs vary vastly depending on the surfactant(s) used. But unless their compositions are revealed, evaluation is difficult and speculative.

E5. Are Water-Based (Alcohol-Free) RCFs Completely Safe for Vinyl?

Not necessarily. The ability of all surfactants to leach plasticizer from Vinyl has been grossly overlooked. As discussed above, surfactant molecules aggregate into small micelles that are capable of solubilizing plasticizers in their hydrocarbon cores. This ability is enhanced by the lower surface tension which allows the surfactant solution to completely wet the Vinyl surface, penetrate deeply into the Vinyl grooves and diffuse into the vinyl matrix to contact the plasticizer.

So, even without alcohol, an RCF containing surfactant—most commercial RCFs—is quite capable of extracting plasticizer out of your Vinyl if the RCF is left on the record long enough. (I found in an unrelated work, that surfactant solutions in water can leach out plasticizer from rubber and PVC sleeves. I switched to Teflon sleeves to circumvent this problem).

Recommendation: With ALL RFCs, it is of paramount importance to remove the cleaning liquid from the Vinyl surface a quickly and as thoroughly as possible with a powerful vacuum.

E6. What Is A Preservative?

Preservative is one confusing term in RCF! It may refer to a compound in the RCF intended for “preserving the Vinyl” or to a compound (e.g. EDTA) in the RCF used to “preserve the RCF” itself. What a mess!

The term Vinyl preservative is a misnomer. Vinyl is an extremely inert polymer that needs no protection from chemical or biological degradation. Like many polymers, however, it is susceptible to UV degradation with long-term exposure to sun light. But unless you intend to play your LPs in a convertible roadster, the UV effect is irrelevant. The term Vinyl “preservative” may refer to other functions: 1) to minimize the loss of plasticizer, 2) to replace the lost plasticizer, 3) to lubricate and thus protect the Vinyl grooves against further mechanical damage, and 4) to change the sonic character of the Vinyl grooves.

E7. Should I Use A Lubricant Or Preservative For Vinyl?

I am impressed by the benefits of such treatment but use it only when necessary because of some naggings concerns. First, with new or relatively clean Vinyl, properly formulated RCF and correct cleaning procedure, plasticizer loss should not be a problem and clean Vinyl grooves should perform just fine without lubricant/preservative. After all, we have enjoyed the sound of Vinyl for years without such treatment. I reserve the use of these additives damaged records that could not be restored by cleaning alone. Second, the sonic signature of these additives remains a matter of debate. Some hear at a quieter and darker background. Others hear subtle loss of details, a slight deadening of the sound. Third, leaving a film of lubricant/presevative on the Vinyl also means leaving behind adsorbed surfactant with the potentially negative effects discussed earlier.

Finally, the fate the lubricant- or preservative film in the grooves in the long run is largely unknown. The electrostatic attraction or hydrogen bond holding this film to Vinyl is probably not strong enough to survive the tremendous and repeated stress of the needle against the grooves (analogy: mechanical breakdown of engine lubricant). Only a few molecules thick, the adsorbed film would be ultimately shredded into contaminants clogging the grooves. The study of thin lubrication film is a difficult and highly specialized area of Science (tribology) that I am not terribly familiar with so I leave it up to you to make your own decision.

For me, without more information, the safest treatment for new or undamaged Vinyl is simply to clean it as well as I can and leave nothing behind. If studies of the long-term effect of lubricant or preservative exist, RCF manufacturers should make them available to customers to ease their concern. After all, we each own hundreds if not thousands of LPs, many of which are valuable or irreplaceable and some of us are understandably reluctant to use additives whose short- and long-term effects on Vinyl must be taken on faith.

E8. What is EDTA?

EDTA has also been called a preservative. But EDTA preserves the RCF itself, not the Vinyl. EDTA is a chelating agent: it preferentially binds with polyvalent cations such as calcium, magnesium, and iron and keeps them from interacting with other active ingredients in the RCF, interactions that can cause precipitations. For this reason, EDTA is also called a sequestering agent. EDTA is generally used in complex mixtures such as hand lotion, hair shampoo, toothpaste, etc. where interactions with even minute amounts of calcium (from hard water, for example) can cause undesirable precipitation. By sequestering divalent ions, EDTA also inhibits enzymes that attend to bacterial activity. This action prevents the bio-degradation of some surfactants (particularly nonionic surfactants such as alky aryl ethoxy alcohol). So, EDTA is a preservative for the RCF, not for the Vinyl.

E9. How Important Is the Quality of the De-ionized/Distilled Water?

Only deionized/distilled water should be used in record cleaning but its residue level may vary. Surfactant-based RCFs do not require distilled water with ultra low residue. Typical de-ionized or distilled water contains only a few parts per million (ppm) of residue, an insignificant amount for the surfactant (several hundred to several thousand ppm), which is designed to handle a far higher level of dust and contaminants from the Vinyl. Furthermore, the level of residue from water pales in comparison with surfactant residue (adsorbed film) left in the groves after cleaning (without final water rinse and vacuum).

Alcohol-based RCFs, on the other hand, handle solid residue poorly—unless they also contain surfactants—and require de-ionized/distilled water with low residue, the lower the better. For the final water rinse, de-ionized/distilled water with ultra low residue is also required as little surfactant is left to prevent water-residue deposit on the cleaned Vinyl. One of the best available water is High Performance Liquid Chromatography or HPLC water. This is “nanopure” water with less than one ppm of total residue; it is usually sold in gallon bottles by laboratory suppliers.

F. HOW TO RECOGNIZE DIFFERENT TYPES OF RECORD CLEANING FLUIDS

We have seen that different types of RCF require slightly different cleaning procedures. But since their ingredients are usually not listed, you have to first figure out which fluid you have in your bottle. That’s actually pretty easy. All you have to do is shake it, smell it and touch it.

F1. Alcohol-Based RCF

1. Foaming. It does not foam persistently when you shake it.

2. Smell. It smells like…an alcohol. Methanol, ethanol and Isopropyl alcohol (or propanol) smell slightly different but share a family scent that we all know quite well.

3. Touch. All alcohol-based RCF evaporates easily leaving that cool feeling on your skin. Unless they contain other additives (e.g. lubricants) these RCFs are thin (non-viscous) like water.

4. Special Care. Scrub vigorously during application to enhance removal of imbedded contaminants but limit the contact time with Vinyl to avoid extraction of plasticizer. There is no need for additional water rinse as alcohols evaporate completely off the Vinyl surface under vacuum.

F2. Surfactant-Based RCF

1. Foaming. When shaken, it produces a lot of foam that persists for several minutes before gradually collapsing. Roughly, the higher the foam, the more concentrated or effective the surfactant is although foaming may be somewhat reduced if alcohol or other additives is also present.

2. Smell. Nonionic surfactants have a distinctive scent akin to that of alcohols but lighter and sweeter. They are the most commonly used surfactants because they are readily available and inexpensive (about $1-2 per pound; typically, less than 0.005 pound is used per quart). Anionic surfactants have a combination of slightly sweet and acrid smell.

3. Touch. The solution feels slick like soapy water and slightly viscous. It does not evaporate quickly off your skin unless it also contains alcohol.

4. Special Care. In the cleaning process, an adsorbed layer of surfactant will always be left on the Vinyl surface after vacuuming. A dry surfactant film does no harm to the Vinyl except for possible static noises (anionics) or a slight deadening of the sound (nonionics), but a wet surfactant film can extract plasticizer. To remove traces of adsorbed surfactant, apply a final rinse with distilled water and dry thoroughly with a good vacuum.

F3. Mixtures of Surfactant(s) and Alcohol(s).

You’ll simply find the combination of above clues for alcohols and surfactants with some masking effects.

Special Care: I also recommend a final water rinse and vacuuming for this RCF type.

F4. Deep Cleaner, Lubricant, Groove Conditioner, Static Suppressor, Etc.

They are either special organic solvent(s) or and/or concentrated surfactant(s) in water. Organic solvents usually have a smell distinct from that of alcohol and do not foam persistently. The best clues for lubricants are a slightly oily feel and/or an increased viscosity. Other additives are difficult to recognize.

Special Care: When groove additives are present, a final water rinse and vacuuming is optional. If you like the sound with the additive (and adsorbed surfactant), do nothing. If you don’t like it, remove surfactants and other additives with a final water rinse and vacuum. Some oily additive(s) will remain on the Vinyl.

G. SUMMARY

G1. Basic Concepts in Vinyl Cleaning

Record cleaning is simple in theory but complicated in practice. Some basic concepts, chemistry and useful steps are summarized below to help you better understand the process and use RCFs effectively and safely:

1. To be effective, a record cleaning fluid must possess many properties some of which are mutually exclusive. An ideal RCF must be able to “wet” the Vinyl surface (alcohol or surfactant), “penetrate” deeply into the Vinyl groove (surfactant), and “dissolve” or “solubilize” contaminants on contact. It must also be able to “transport” (foam) solid contaminants away from the Vinyl surface and leave behind after vacuuming no residual film that could affect plasticizer and sound. During cleaning, a good RCF must not extract plasticizer from Vinyl rendering it brittle and susceptible to damage.

2. No single fluid can offer all desirable properties above. While water is the safest fluid to use, effective cleaning is not possible with water without additives. Most commercial RCFs include several cleaning agents—typically alcohol(s) or surfactant(s) or both—in water that provide the balance between effective cleaning and minimal harm to Vinyl.

3. All cleaning agents (additives) have their advantages and disadvantages. Alcohols (in water) are not very effective at deep cleaning but can dissolve a wide range of contaminants and evaporate completely under vacuum. Surfactants (in water) can provide exceptional cleaning (by solubilization). This effectiveness, however, strongly depends on the surfactant type, molecular structure and concentration and can be contaminant-specific. (When a minimal amount of surfactant is used, it serves only as a wetting agent.) Just like alcohols, surfactants can also leach plasticizer from Vinyl with prolonged contact. Unlike alcohols, surfactants can leave a sonic signature if the adsorbed film is not completely removed.

4. For deep cleaning, some RCFs use concentrated surfactant mixtures and/or organic solvent(s) other than alcohols. These cleaners, which are capable of removing mold release, may also extract plasticizer from Vinyl given enough contact time. Thus, deep cleaning should be reserved for special cases and should not be frequently repeated.

5. Whether you use alcohol-based or surfactant-based RCFs or others, the contact time between RFCs and Vinyl during cleaning should always be minimized to reduce plasticizer extraction from Vinyl.

6. After using a water-based RCF, additional water rinse and vacuuming are usually beneficial. All RCF ingredients adsorb on the Vinyl surface as a thin film that can be difficult to remove with vacuum. Unlike alcohols which completely evaporate under vacuum, RCF ingredients like surfactants and other additives should be removed with water and vacuum to avoid plasticizer loss, static noises and other deleterious effects.

7. Proceed cautiously with Vinyl lubricant, preservative and additives other than surfactants and alcohols. While they can offer sonic benefits, their long-term effects—sonic and otherwise—remain unknown and have not been made available by the manufacturers.

8. Different types of RCF require a slightly different cleaning procedure. Alcohol-based cleaners require vigorous brushing to help dislodge contaminants. Surfactant-based cleaners require additional water wash and vacuum to remove adsorbed surfactant film. When a lubricant is also used, this final rinse is optional and contingent on your preference for the sound.

9. Only low-residue de-ionized/distilled water should be used for record cleaning. Surfactant-based RCFs, however, do not require ultra-low residue water as the surfactant designed to handle large amounts of residue and contaminants from the Vinyl can handle water residue as well. Alcohol-based RCFs, on the other hand, handle solid residue poorly and require de-ionized and/or distilled water with very low residue. The final water rinse in particular requires de-ionized and/or distilled water with ultra low residue.

10. While RCF ingredients are often not listed, you can have an idea of the type of RCF by simply shaking, smelling, and feeling the fluid. Whenever possible, request a Material Safety Data Sheet (MSDS) for any RCF or household cleaner before using it. This is a good way to obtain the list of all the ingredients (active and inactive) and their potential hazards.

G2. Parting Shot

It is my fervent hope this primer will provide you with the basic understanding to undertake the task of cleaning your treasured LPs with confidence and safety. As this piece was put together with some haste, your questions and help in pointing out the unavoidable deficiencies and errors will be greatly appreciated. Thank you for your time.
justin_time
Well I know its been a few years since this post but I'm wondering why (maclogan) said that Justin Time his remarks are wrong in plasticizers. Do you care to elaborate and help us understand better. 
an old thread but excellent indepth read!

Its interesting to note that pretty much all types of cleaners (alcohol free or not) might have the potential to leach plasticizers. Its my view that many so called safe alternatives to alcohol could be explicitly more damaging and likely to do so. At least isopropanol has been tried and tested for many years, the threat of heavily diluted alcohol based fluids seems negligible, certainly safer in my view than many other unknown concoctions.

I personally use a RCF called Clear Groove http://cleargroove.co.uk and have done for many years, its IPA based but have never noticed any deterioration even with records cleaned several times.

I think as pointed out in this article  - The key is to ensure the fluid is not left on the vinyl for longer than necessary and that a final rinse with di ionized water can be be beneficial.
09-25-12: Maclogan
Justin Time may have known something about the chemistry of solvents and surfactants when he wrote this. But he didn't know very much about what goes into the mix that we call "vinyl", and he is apparently ignorant about what happens during the pressing process. His remarks on plasticizers and mold release are wrong.
Rather than make a accusation that someone is just wrong, which is kind of a thread crap, maybe you could enlighten us on what you believe is true and what your credentials are for knowing this. It is not that someone couldn't have misspoke, however unintentional, but it is that you have shown nothing to validate your assertion. At this point, I think Justin_Time's intentions were admirable and delivered far greater technical information than many of us had before this article was written. Understand also, it is seven years plus old without modification.

Happy Listening!
I have heard second-hand that the "mold release" is actually blended into the vinyl and not a surface application to the mold. Would be nice to get a definitive answer since that would seem to have a direct bearing on the chemical requirements for a RCF.
Maclogan, please inform us of the truth of these matters and if you are able, tell us how this effects the recommended RCF.
Justin Time may have known something about the chemistry of solvents and surfactants when he wrote this. But he didn't know very much about what goes into the mix that we call "vinyl", and he is apparently ignorant about what happens during the pressing process. His remarks on plasticizers and mold release are wrong.
Justin ,thanks for a great article. I want to make my own RCF and was wondering how much EDTA I should add as a preservative? I plan to use Triton X114 as a surfactant.
Justin time, seven years later, thank you for sharing a most exhaustingly comprehensive, relevant, and informative topic with all of us vinyl lovers!

Happy Listener!
Using enzyme based cleaning fluid I found a claim on Walker Audio which said
"That It is important to understand that the enzymes remain active for only about eight to ten hours before they die".
So does that mean the 1 gal of VPI cleaning solution I made up last year is doing sweet FA when it comes to cleaning my albums?
As I am no a chemist and no nothing about enzymes and there life span can someone elaborate?

Does a record cleaning fluid that uses enzymes only have a working window of 8 hours, or is this statement just marketing bull?



04-10-08: Jamnperry
No, it's true. I work with enzymes. We keep them refrigerated as well.

Punkuk
So after they die are cleaning fluids that use ennzymes ineffective?

If so this is huge for all those sellers of enzyme based cleaning products.
How does this affect liquid concentrate vs. solid based cleaning products?
Justin_time, Wow, thanks for taking the time to give us an excellent primer on RCFs. It was very interesting and informative - the best I've read on this subject. Being an retired engineer with a chemist best friend, both audiophiles, I'm going to try these.
.
Justin_time,
.
Thanks for the time and effort you put into this post...a great help and greatly appreciated.
.
Rgds,
Larry
,
Thanks Ketchup & T_bone...wouldn't have been aware of this without your posts.
I'm resurrecting this thread. Nice post, FWIW! Someone mentioned Micro concentrated cleaner. I happen to have a jug of this. Would this work well as a surfactant?
Sorry I shouldn't have jumped ahead, i realized from reading some of the responses indepth that my access is more in line with the tween-20 and x-100 questions, than the specialized surfactants you have created. never the less, Thanks for a great and informative post! I really enjoyed it.
Hi justin time, I have access to laboratory grade surfactants, alchohols and ddH2O de-ionized and what not, do you have any recipies/protocals that you prefer? I enjoyed your post, and was thinking about formulating my own solutions, but thought perhaps you might already have a few jems you could share.

Thanks

Ben
Thank you, Justin_time.

I have long advocated (well, for a few years anyway, my theories are ever evolving) multiple cleaning steps and fluids to effectively clean a record. I have saved this treatise and expect to refer to it many times in the future!

I also applaud your lack of commerical brand reference; very professional.

I have posted my record cleaning regime a number of times at AA, which I will cut and paste here for sped redding sake:
[b]
It might be best to think of records as plate glass rather than pots and pans, but the point must surely be: they have a lot more on them than you think, and it takes SEVERAL steps to get it all off. Anyone thinking otherwise is deluding themselves.

Yes, my regime is probably a bit excessive, but five minutes once at the beginning of a relationship with an album seems a small price to pay. Less than that and you will be listening to dirt.

1) alcohol-free pre-rinse solution (I use RRL SDC and distilled water)
2) vac off sludge
3) DD fluid
4) vac off sludge
5) Pure 2
6) vac off
7) RRL SVW
8) vac off
9) distilled water (triple distilled and filtered)
10) vac off
11) rack dry one hour

Pre-rinse intention is to remove the big debris, like dust and etc.
DD is an intense, sudsy, scrubby bit to loosen and remove the larger portion of dirt.
Pure 2 is a less sudsy, less intense, solution intended to remove the remaining DD fluid and sludge
RRL SVW is suds free, very low intensity, solution intended to remove the Pure 2.
Distilled water to remove the last bits of any of the remaining.

You will note that each step is designed to remove the residue of the previous step.

After that, the record is clean, no ifs, ands, or buts. You should never need to do this again for that particular record.

Do you wear glasses? Have you ever cleaned a car windshield? You will know what I mean about cleaning glass.
Sirspeedy. Most though not all surfactants used in RCF are bio-degradable. So most commercial RCFs use a preservative to extend the product shelf-life from several weeks to several years.

Most common preservatives used are EDTA or citric acid. If you make your own RCF, it will usually last from a few weeks to a few months without preservatives. You'll see some cloudiness and eventually grayish flocculants indicating decomposition and bacterial/fungal growth. So make up a small quantity at a time.

If you use a preservative, please stay away from harsh chemicals such as ammonia or acetic acid (vinegar). They work but their long-term effect on Vinyl may be harmful. Your LPs are too valuable to take this kind of chance.
Oregon—The best way to keeps your records free of clicks and pops is to take great care of them while they are still new—you may want to read my more recent thread on how to care for new records. Once the noises are there, they are very difficult to get rid of.

One way to reduce or eliminate the pops and crackles is to use a deep cleaning system, such as the RRL the Super Deep Cleaner followed by the RRL Super Vinyl Wash. There are similar commercial product out there that I am less familiar with. Some love the quiet sound of LPs treated this way, others—a small minority I must say—claim that the treatment deadens the sound a little. For very noisy albums, I feel deep cleaning is well worth any minor drawback.

The type of brushes to use rush is a controversial topic—like most audio topics—I would rather not get into. It is essential though to use a brush with very fine bristle—the high frequency grooves are exceedingly small, in the order of 0.1 micron in the top end. While applying the RCF, brush vigorously back and forth along the grooves to help dislodge small imbedded particles and contaminant film and help the surfactant do its job. Mechanical energy (elbow grease) AND chemical energy (RCF) are needed together for a thorough cleaning.

To provide easy, effective and safe cleaning, a record cleaning machine (RCM) is absolutely necessary. There are many fine RCMs (Nitty-Gritty, VPI, Loricraft) available within a wide price range ($300 to $2000). I feel that if you have more than 100 records, a RCM is a good investment. Some manual cleaning kits are far less expensive but not nearly as effective or easy to use. For general articles on record cleaning, you may want to check the following sites:

http://www.musicangle.com/feat.php?id=54
http://www.smartdev.com/Cleaning-tutorial.html

There is much useful information in these articles to help you get started on record cleaning. Just beware that some information is outdated, some is controversial, and some is plain wrong. You may have to dig a little deeper to get a broader view and make up your own mind about what to do. Look for the science, not the hype.
Good Luck and Happy Cleaning.
Justin-time,
Thanks a bunch. Lots of this is over my head, but I read every word with interest and a desire to find the best way to care for my precious LPs. Your time and effort is greatly appreciated.
What lead me to this thread, specifically, is how can I get rid of those annoying pops and crackles. You mention deep cleaning, micro particles etc. But which approach is best for removing the cause of the pops and crackles.
When you say "vigorous brushing" do you mean to say back and forth pressure with a soft cotton cloth, or a type of brush? One direction swiping? Please explain in detail the physical aspects of cleaning along with the ingredients, if possible (for us boneheads).
Is vacumming a must (I don't own one) or will manual/physical drying with soft cotton cloth be sufficient?
Any audiophiles are welcome to email me with their ideas/opinions, don't be shy!
Sincerely, Oregon
Excellent discourse and expository, Justin. Thanks for your efforts and your illuminating post.

Best regards,
Paul Frumkin
Wonder what Art du Son is, with the partially dissolved solids, not unpleasant odor,...

Nice piece; thanks.
Answer for Mikelavigne

Thank you very much for your aprreciative words. I have used the Nitty-Gritty and VPI record-cleaning machines and have been very satisfied with them, especially the VPI.

I have not used the Loricraft machine or fluids so I cannot comment on them. Sorry.
Justin_time,

I hope you have some success finding a way for us to get some of the surfactants you think would be good. I appreciate your willingness to come up with some formulations for us as well! I would imagine if the volume required to purchase is large, like the quart of Triton mentioned by Stylinlp, there would be people here who would be willing to split the cost etc. to make it sensible. I would be willing at least. Thanks again.

Matt
Dear Justin: Great , great post. I think that is the most complete ( a bible ) information about wet cleanning LPs.

I use the dry technique to clean LPs that I take from Dr. Van denHul.
I use the wet way only in the new LPs or second hand " new " comers LPs.
My everyday clean-up is always: dry way. I'm happy with it. As a fact I think that the best LP cleaning procedure is what the stylus makes during playing. So, it is critical to maintain in pristine condition the cartridge stylus.

Well, this is what is working to me.

Regards and enjoy the music.
Raul.
A big thank you for this thread Justin_Time! Your right that the audiophile community needed an article like this. One of the audio websites should post your article or sticky it somewhere. Extremely valuable information.

In my quest for a diy record cleaning fluid I called around for Triton, distilled water, etc at differant suppliers locally and nationally. I had a really tough time trying to order in lesser quantities to make it worth it. I think the lowest quote for a quart of Triton was like around $40. Just to add a few drops to my RCF. Ouch. Then calling around for better distilled water than they sell at Walgreens was almost impossible to.

So I gave up on it and just went with 4 parts distilled water, 1 part Electronics grade 99% ISO Alcohol, 1 drop of Dawn dish detergent. From reading your article I guess this is a good formula. Then suck it all off with my DIY vacuum machine quickly. :)
thankyou!! i appreciate a real expert taking the time to shed light on this very important issue for us vinyl lovers. even though your initial post was long; i felt that you gave the proper background so even a klutz like me can get a feel for cause and effect. i'll now go read the ingredients of all my various fluids and decide which to use when.

your communications here are particularly timely for me. i've been collecting records for about 10 years and have around 5000 so far. up until a few years ago i was constantly cleaning them (i've cleaned about 3000 so far).

due to other audio related projects and the noise level of my record cleaner i have not cleaned many for a couple of years. i have just purchased the Loricraft PRC3 (to replace my VPI 16.5) and plan to begin again in ernest cleaning prior to playing on a regular basis. i went with the Loricraft to get a quieter machine and i bought into the idea that their different approach to vaccuum cleans better.

i have a question for you since you seem to recommend a strong vaccuum;

do you have an opinion about which vaccuum approach is better......VPI or Loricraft?

Loricraft info

with the Loricraft i purchased a 'group' of chemicals that are recommended for use in various situations. i wonder how close their chemisry will match the logic of your post.
Jyprez: Thanks. I am familiar with old RCFs like the First and Last fluids, and some newer RCFs like the VPI, DD and RRL. But I have not used the Audio Intelligent fluid.

I have refrained from making direct comments about commercial RCFs and will continue to do so because I want the primer to be about general understanding of how RCFs work and not an indictment or endorsement of any commercial products. Let me just say that they all have their strength and weakness. If you quickly review my summary in the primer, I am sure you can pretty easily draw the correct conclusion yourself about any of those products. I hope you don't mind.

While I was not busy doing real R & D work in the lab, I messed around a little with several common as well as exotic surfactants--I get most of them as free samples--and came up with quite a few outstanding RCFs. Unfortunately, I am your typical reseach scientist and have no head for business. I have no intention or desire to commercialize any of these products. I thought about patenting the formulations but didn't because I didn't think there would be much of a market for RCFs.

I am checking with a few people to see if it's possible for individuals not associated with R & D labs or companies to buy some common surfactants directly from lab suppliers. If this is possible, then I will recommend a few simple formulations and let you guys make your own RCFs that will be effective, safe and inexpensive. Let's keep our fingers crossed.
Great post. I learned a lot. Tell us more about your views on the current RCF's out there such as Audio Intelligent and Record Research. I use both for different purposes.

I, for one, would be interested in purchasing some of your custom RCF's for evaluation.
Thank you Scott for your words of appreciation.

I really did not mind the negative responses. It's just not possible to please everyone and not everyone have the patience to read long writings these days, especially about arcane concepts in surface chemistry.

Unfortunately, my aim was not simply to offer tips about RCF; my main goal was to explain basic concepts that in the long run are more helpful to readers as they can make their own informed decision in a wide variety of situations. This kind of discussion requires space. No doubt this primer could have been considerably shorter but this meant spending a prodigious amount of time editing which, I must admit, I was loath to do—mental constipation usually causes verbal diarrhea.

In the whole scheme of things, if the information above helps just a few fellow LPs lovers get clean sound out of their Vinyl beauties and keep them safe for years to come, I consider my time writing this primer well spent.

Once again, thank you very much for you support.
You went to alot of effort for the sake of others and their prized albums. Yet a few Losers post what I would consider rude responses!?

I appreciate the education. Thanks again.
Scott T.
Answers for Zmrs13, Mab33 and Oplachip

Answer for Zmrs13:

With your background—frighteningly similar to mine—you won’t have any trouble making up your own RCF. I think your best bet is with the Triton.

Triton X series are nonionic surfactants (ethoxylated t-octylphenols). Like all nonionic surfactants, they work on the principle of hydrophilic-lipophilic balance or HLB, which is just a fancy way of defining the balance of solubility in oil and water. An HLB of 12 is in the middle of the range. I have worked extensively on these and similar surfactants (e.g., the Igepal CO series with a straight nonylphenol rather than a t-octylphenol tail) but I have not tested these surfactants specifically for their effectiveness in record cleaning.

The Triton X-100 may work just fine but you may have to try and compare three different Tritons to find the one that works best. They all have the same tails (branched octylphenol) which give them oil solubility and different heads (ethoxy groups or EOs) which give them different water solubility, solubilization power and foamability.

Triton X-114; tail = 7-8 EOs; HLB = 12.4
Triton X-100; tail = 10 EOs; HLB = 13.5
Triton X-102; tail = 12(?) EOs; HLB = 14.6

By the way, I think the Aldrich website makes a mistake and gives the formula for Triton X-301 (a sulfonate) instead of Triton X-102

You should use about 0.1 to 0.2% by weight of active surfactant. Though the tail is slightly branched (less chance of making viscous phase with oily contaminants), you should still use 10-20% IPA to help reduce bacterial growth and biodegradation of the surfactant.

The Tween is a sorbitan monolaurate, also a nonionic surfactant. It has a polysorbate or polyoxyethylensorbitan head (POE). I think Tween 20 may be too water soluble to be very effective. You may consider two other Tweens:

Tween 21; head = monolaurate; tail = 4 POEs; HLB = 13.3
Tween 40; head = monopalmitate; tail = 20 POEs; HLB = 15.6
Tween 20; head = monolaurate; tail = 40 POEs; HLB = 16.7

I have not used these surfactants myself for RCF but nonionics work similarly and I can’t see why one of the Tweens shouldn’t work, especially Tween 21.

Please remember that all these nonionic surfactants with ethyleneoxide (EO) groups are actually mixtures with Poisson distribution of EO groups. There are small fractions that are very oil soluble which could cause problem with extraction of plasticize given enough timer. So don’t leave the RCF on the Vinyl longer than necessary.

Finally, if you have access to product from Aldrich catalog, there are many other surfactants that are also worth considering.

Answer for Mab33:

Zmrs13 has access to Triton X-100 and Tween 20. You may want to contact Zmrs13 directly. Aldrich may let you order surfactants directly even though you are not with R & D or University labs. I got all my surfactants for my R & D work as free samples or synthesized them in the lab and never had to purchase them myself. Sorry I can’t be more helpful.

Answer for Opalchip:

I use surfactants as cleaning agents and alcohol as additive to ease vacuuming (less viscous phase) as well as to retard bacterial growth and surfactant biodegradation. They seem to remove most contaminants I’ve encountered on Vinyl, including mold and mildew. I have never used enzymes on Vinyl. Enzol and Medzyme commonly used in the medical field may do the job but I have no experience with them.

As for Alconox, I use it all the time in the lab as detergent for cleaning glassware. But I have never considered it for record cleaning because this is a commercial product, not a reagent-grade surfactant. The main surfactant is a dodecylbenzenesulfonate, a good but not great surfactant for record cleaning. It also contains sodium carbonate, tetrasodiumpyrophosphate and sodium phosphate as additives which are definitely not good for Vinyl sound.
Any thoughts on using enzymes in the mix to remove mold/mildew that (supposedly) alcohol and surfactants are not too good at? (Such as Buggtussel's Vinyl-zyme, Audio Intelligent, or Phoenix cleaners)

Also, how about the medical grade detergents - some of which are specifically formulated for REPEATED use on expensive flexible plastic and rubber instruments such as endoscopes. Many of these are a potent combination of surfactant and enzyme. I would think that any significant removal of plasticizers would have been considered in formulation as a big No-No. Here's a couple of examples:

http://www.sterrad.com/products_&_services/cidex/enzol/faqs/index.asp

http://www.sipcobio.com/products1.html

Or from the Alconox catalog: "Concentrated, anionic detergent for soak, manual and ultrasonic cleaning. Free rinsing to give you reliable results without interfering residues. Mild cleaner prolongs instrument life. Ideal for cleaning oils, particulates, silicon mold releases, buffing compounds and contaminants from glassware, metals, plastic, ceramic, porcelain, rubber and fiberglass. Excellent replacement for corrosive acids and hazardous solvents. USDA authorized. Dilute 1:100. pH 9.5

Any thoughts?
I'd be interested in trying some of these surfactants you've found to be good for vinyl. Any way I can get some???
I'm a retired PhD in Chem E with 25 years R&D experience at a major chemical company.
The sigma aldrich catalog has most everything I think we need along with properties.
http://www.sigmaaldrich.com/Area_of_Interest/The_Americas/United_States.html
Mab33: I don't have my reference books with me at home and I do not recall the exact structure of the Tween 20 or Triton X-100. But I think they are both commercial nonionic surfactants of the nonylphenol ethoxylate types that are high purity. There are other similar commercial nonionic surfactans available such as Brij, Igepal, etc. which will also work. I think they differ in their alkyl chain length as well as in the number of ethoxy groups.

Generally, these Tween or Triton surfactants should work fine (at 0.1 to 0.2% active concentration in water) but they come in a huge choice of EO (ethoxy group) numbers with give them different oil/water solubility balance(HLB). Some will work much better than others for record cleaning but I have no way to telling which ones without looking up their molecular structures and running a few tests. They are definitely better than household cleaners.

Make sure you add some aclohol (10-20% IPA) to reduce the chance of making viscous goop with oily contaminants and also to help prevent biodegradation and bacterial growth (these surfactants will do that in a few months).

By the way, could you tell me how you can get these products? I usually got them as samples for R & D work in the labs but I never had to buy them as individual.
Mab33: Thanks. As incidental byproducts of my R & D work (totally unrelated applications) I have discovered several nearly ideal surfactants for record cleaning. They work at extremely low concentrations (less surfactant, less residue), provide ultra lower tensions (deeper cleaning) and can clean all kinds of oil including mold release without problems (no need for alcohol or two-step cleaning). Best of all, due to their highly unusual structures, these surfactants leave no sonic signature so they don't really require additional rinse with water.

If it sounds too goo to be true, it sort of is. Many of these surfactants are propietary molecules that we synthesized ourselves in the labs in small quantities for research purposes. A few are available in commercial quantities; they are very expensive specialty surfactants, although you need only about 4 or 5 drops per gallon of water for record cleaning so their material cost is basically irrelevent. The real cost is in the R & D work to study their properties, which is free for me.

I have used these very simple and very safe fluids to clean my own records for years with great success. I have patented several surfactants for other applications but I have never thought of producing commercila RCF because I am your typical research scientist who has no head for business. Besides, I don't think there is much demand for RCF to make it worthwhile. I may be wrong.
Many thanks for the informative post. Can you assist those of us who do have access to reagent grade constituents so that we can minimize our leaning curve? Some recommended surfactants and detergents would be appreciated. For example, I have access to both Tween 20 or Triton X-100 along with deionized water and reagent grade isopropanol. I also have a bottle of Micro cleaning concentrate which says no residue and safe for plastics. Should I use it?
Great post! I'm left wondering why you haven't started to produce a RCF for the rest of us???
Thanks for the post. It is long, but it's exactly as you mention in your opening statement - the punch line is in the summary for those not interested in the technical detail. I printed it out and have added it to my reference file.

thanks again.
Thanks for your well written and interesting piece. It made me wonder most about the balance between elasticity and brittleness. Wonderful!
Response to Rcziech about homemade fluids.

I agree with you that commercial RCF can be expensive. What you are paying for is not just the material but the expertise and the R & D work as well. That's why I make my own cleaning fluids.

Unlike most people, however, I have access to extremely pure water and alcohols (and any other solvents that I need) and a huge variety of esoteric surfactants to choose from which are structurally well defined, extremely pure and fully tested for performance.

I do not recommend that you make your own record cleaning fluids because like most people, you cannot get laboratory-grade chemicals and must rely on household products. When you do that, you cannot get the right ingredients, or the right purity, and you are also stuck with many known and unknown additives (colorant, perfume, solvent, enzyme, phosphate, etc.) that you don't want.

But if you must make your own cleaning fluid from household products, here is something that is pretty efficient for general record cleaning and pretty safe (disclaimer: the responsibility of using this product is yours alone):

1. 0.25 to 0.5% by weight of Woolite Fabric Wash (roughly 2.5 to 5 grams or 40 to 80 drops per quart of cleaning fluid). Woolite contains 20% or less of sodium laureth sulfate and sodium dodecylbenzene sulfonate and no enzyme or phosphate. You may also use Dawn or Palmolive dish liquid which are more powerful cleaners (30 to 60 drops per quart). Dawn and Palmolive dish liquids are mixtures of nonionic and anionic surfactants, I believe, with 40% or less activity. They do contain many other additives as well (10 to 20% alcohol and, among other things, blue or yellow dye and perfume). The final active surfactant concentration in your cleaner will be approximately 0.05% to 0.2%, which is a good range for most cleanings. You may adjust the concentration to get the performance that suits your need.

2. 10 to 20% pharmaceutical-grade isopropyl alcohol by weight or by volume. You can get this alcohol at any drug store. The alcohol serves to reduce the risk of viscous phases formed by surfactants and some contaminants that are hard to vacuum. It also helps prevent excessive foaming as well as delay bacterial growth in your cleaning fluid.

3. About 80 to 90% water. Use the best de-ionized/distilled water with low residue that you can find to make up the rest of the cleaning fluid. I think grocery stores (and perhaps auto-part stores) carry these products in gallon jugs.

Other forum members might know of places where you can get chemical-grade surfactants and ultra-low residue solvents. I can't help you there because I never had to do it outside of my labs. I want to re-emphasize that I do not recommend that you make your own record cleaning fluids from household products because of too many impurities and unknown additives, but it you must, above formulation should work well and is pretty inexpensive to make. Of course I cannot guaranty the safety of using it even though I know it works fine.

Just don’t forget to rinse everything with distilled water and vacuum one final time.
Justin time, Thanks for putting it down so we can all nibble at the text until we get it straight. Actually, many topics requiring a thousand word text do resist being reduced down to just a precious few words. That's what a picture is good for :>)
Bringing your information to this site from other places is great for those of us lacking time to search for ourselves.
Your much appreciated review does show nothing in life is ever as simple as it first appears.
Great post. But, how about some info on where the common man can get these ingredients(common names etc) to mix their own. Ready made RCF is very expensive.
Excellent post. Even though alot of it went over my head, I did get alot out of it. Thank you!