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Back To Static!

We had a long discussion on the possible causes of static electrical charges on records in another thread. We just had a real good cold snap in New England dropping the humidity to under 20% so I was able to run a set of qualitative experiments documenting some surprising results that I hope will clear up a lot of the mystery and help people contro static charge and the accumulation of dust on their record. 
Static field meters are expensive.  The cheapest one I could find cost $260. I had to find a more sensitive way to measure static as it became apparent that using your own hair is very insensitive. Studying the Triboelectric series I noted that polypropylene is at the opposite end to PVS.  I have polypropylene in the form of suture material, the blue thread that many of you have seen. I tied a length of 6-0 Prolene  to a wood dowel and it worked beautifully. The PVC attracts it like a magnet and the Label repels it. It will pick up very small charges that otherwise go undetected. I can now define four conditions; No charge, Light charge, Charged and Heavily charged. It turns out that completely discharging a record is not easy. The label will actually donate electrons to the vinyl over time reaching an equilibrium point. Totally discharging a record required using a Pro-Ject conductive record brush wired to ground. If I suspend a discharged record (no thread activity) by it's hole within 30 minutes it will develop a slight charge (vinyl attracts the thread, label repels it). This will appear to us as an uncharged record. 
Does playing a record increase the static charge?  Yes absolutely, and the charge is additive. Playing the record over and over again progressively increases the charge from slightly to heavily charged. 
Does how you store the record effect charge? Yes absolutely. Records stored in MoFi antistatic sleeves come out with the baseline small charge. Records stored in paper come out with a noticeably higher charge. These are records that have been totally discharged prior to storage. A record that is charged when you put it away will come out at least as charged even if you are using anti static sleeves. Do conductive sweep arms work? Sort of. If the sweep arm leads the stylus charge will still accumulate. The brush has to track with the stylus. 
Unfortunately, I could not get hold of a Zerostat to test it's effectiveness. Regardless, a charge will accumulate with play.
The single best way to totally discharge a record is a conductive brush wired to ground. Just holding it will not work as well. The impedance of your tissue is in the megaohms. You want a dead short. Even so, a small charge will accumulate over a short period of time. The safest assumption is that there is always a charge on the record attracting dust. So, don't leave records out for any period of time. In regards to the hot topic of dust covers, a properly designed Dust cover does not affect sound quality. If your dust cover does effect sound quality in a negative way then you have a choice between sound quality and dirtier records. Your records, your choice. 
I would love to be able to stage voltages. If in the future I manage to come up with a static field meter I will repeat all of this in a quantitative way. Humidity is a huge factor. Those living in more humid environments have less trouble with static accumulation. I suspect everything occurs in like fashion just the voltages are lower. Lower to the point that they do not need any device to lower the charge?  I don't know. 

128x128mijostyn
elliottbnewcombjr
5,112 posts
 
Thanks, I will start using the anti-static sleeves I bought.

wand demagnitiser?

just curious, I have wand demagnitizer for my R2R deck. 

Any advantage relating to static to use on nearby TT, or LP's just placed on the platter?

Avoid anything?
tubegb's avatar
tubegb
187 posts
 
It would be good practice to keep any tape head demagnetizer well away from your phono cartridge, especially a moving magnet design.
antinn
369 posts
 
@mijostyn,

No arguments that there may always be some static charge under some conditions.  Someone over at the Steve Hoffman site has been doing some cleaning agent comparisons (with some input) and has a static field device, and after full wet cleaning the record surface measures <0.200 kV but his background humidity is in the 30's. Once the background humidity gets above 45F dewpoint (same as 40% at 72F) the moisture layer that naturally forms on the record should be enough to dissipate most static charge; noting that what condenses out of the air is slightly ionic.  So, in you current situation with humidity <20%, the static that is forming is likely just the consequence of the record spinning in the very dry ambient air.  

Not sure how the label that is bonded to the polyvinyl-chloride-acetate (PVCa) transfers electrons the record.  Either way for my application, with the paper in contact with the metal spindle, any charge should be  dissipated.  I also have a reflex clamp that is plastic in contact with the label w/metal top/threads that could help to dissipate the charge from the label.  One thing you have to consider is that when controlling static, the term anti-static includes materials that are conductive and dissipative.  Very often in ESD control, ESD ground straps will have a 1 meg-ohm resistor built-in to control how fast the static charge is dissipated; and the time duration is just a few seconds.  For work surfaces they do not want fast discharge - it can damage a microchip when placed on the mat, so they slow down the discharge to be dissipative. 

So, although by convention the record material is considered an insulator, and static develops on the surface, that does not mean it cannot dissipate charge through the material - but very slowly.  The ESD mat top surface is vinyl - but it is dissipative across its surface and through its surface to the center conductive layer.  But, the heavier ergo thicker record, dissipation through the record will much slower.  Also, the high static charge that forms is not uniform, the articles measured it as islands.  


slaw's avatar
slaw
20,403 posts
 
My reason for posting was to show that proper grounding is a big factor to getting static under control, as @antinn  wrote in the link he provided. My mentioning of my use of MyMats was to show that with proper grounding, I'm having no issue using them.

@mijostyn, asked me to try the ESD mat. Why would I want to when I'm getting excellent results?
lewm
12,456 posts
 
Magnetization and static charge are two different things, even though both result in an attractive force between two objects. But don’t expect a demag to have any effect on an existing static charge, except where the charge might jump from the object to the demag-er, just by chance and proximity. (In response to Elliot's post.)

Mijostyn, Besides the fact that paper and vinyl may be at opposite ends of a tribo-electric chart, what is the basis for your hypothesis that the charge is ping-ponging between them? Have you experimented with an LP from which the paper label was carefully removed? That might be useful.

In the white paper on static charge vis LPs, published in the 80s, Shure Corporation scientists pointed out that if you remove the charge from the surface of an LP sitting on a platter, the reverse side, which sits against the platter, will retain whatever charge it had a priori. As soon as you remove the LP from the platter, any residual charge on the non-playing surface will re-distribute itself evenly over both surfaces. I think that rapid process of charge re-distribution is what sometimes one hears when removing an LP from a platter, as a faint tinkly sound.
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