Silver solder--what wattage soldering iron?

I need to solder some new Cardas cartridge clips onto my Rega RB600, and I'm having trouble using a Radio Shack 40W soldering iron with the silver solder that came with the clips. Doesn't seem like I'm getting enough heat, even after I cleaned the tip with sandpaper. Does this iron have enough wattage, and if not how much do I need? Thanks, Will Herrera
I hate solder with silver period. It always need extra heat to operate and doesn't shape up correctly plus you have a chance of 'frying' the tiny tonearm wires
IME, this is somewhat delicate and you need a better iron. I can recommend Weller, with a 1/32 tip about 650-700 degrees F. This kind of tool is what provides that "simple, quick touch" solder.
Try using some flux which is 'acid based' to clean the metals. It is made just for soldering. I haven't soldered or brazed with silver for about 35 years but without the flux it will never make a decent solder/braze joint.
40 watts is MORE than enough. Are you heating the wire first, then adding the solder? Make sure to use alligator clips for heat sinks so as to not melt the dielectric. If your out of practice, practice on some spare wire of the same (or close to the same) gauge.

I do power cord soldering w/40 watts.
I would get a better iron. There are ones with variable power available now that I wish had been around when I could see well enough to use them. I also used Weller, usually 25 watts.
When I learned electronics in the 60's, acid flux was a no-no for electronics. It would cause corrosion in the weeks following the solder operation. Acid was for plumbing only.
I struggled with the same problem when I had a 40 watt Radio Shack soldering iron. A 25 watt Weller made an enormous difference. It seemed hotter despite a lower watt rating. If you plan to do more projects, get a better soldering iron. You'll save yourself a lot of time and cursing. I've heard excellent comments about this $15 station from Parts Express:

Stahl Tools Variable Temperature Soldering Station
Mingles, that one even looks like a Weller. For that price it would be hard to beat. It would be nice if it had a temp readout, but that would probably drive the cost up. :-) Heck, that would make a great backup iron.

Yep, I had one of those Rat Shack irons a while back. It is not the power rating that makes it not perform, it is just a cheap tool. I found it required longer contact time to heat anything up, then found that the soft material the tip is made from doesn't last very long and they don't sell replacement tips for it. I mean the tip literally burned away to a stub. In honesty, the poor thing was probably overworked with all of the projects I've done in the last few years.

With cartridge clips and fine wire you want something that will do the job fast so there is less chance of the heat traveling. Just my .02 based on my experiences.

I can highly recommend the Cardas silver solder. I bought it from Michael Percy Audio, but it can be found other places. The Cardas solder does seem to take a bit more heat, but once it begins to flow it works beautifully.
Thanks everyone for your comments and suggestions. I finally got the clips soldered, after spending the day trying 3 different soldering irons (2 40W ones and one 15W/30W). The solder ended up flowing fine using the dual wattage iron on the 30W setting. The enclosed ends of the clips where the wires attach ended up getting completely filled with solder---I ended up applying the solder quite liberally to make sure I got a good weld. Which brings me to the next question---is it possible to have *too much* solder on a cartridge clip? I've since remounted the arm on the table and everything sounds as it should, so apparently my solder joints are competent, but still I wonder if the amount of solder has any effect on the sound (typical audiophile nervosa question) any case the whole ordeal was a major PITA and I have no plans on soldering again any time soon...wonder if I should've just gotten that Incognito rewire afterall...;) Will
is it possible to have *too much* solder on a cartridge clip? I've since remounted the arm on the table and everything sounds as it should, so apparently my solder joints are competent, but still I wonder if the amount of solder has any effect on the sound
Will, as long as the joints are good, a little extra solder won't harm the sound. For what it's worth, the Incognito requires soldering the cartridge clips.
Hi Mingles---I wouldn't have attempted the Incognito rewire myself, I would've sent out to get it done.
I am with Marakanetz. I used to use silver solder, but no longer do. tough to get a good solder joint, and its not a eutectic solder. Sometimes can sound bright too.

I switched to Koester 63/37 with a 285 flux. much nicer sound, less corrosive flux and good solid joints.
One thing to note is that with silver you have a chance of making the connection brittle. Take care to not overheat the joint.
One more thought - consider a temperature controlled iron. These have a thermal sensor near the tip and vary power as required to hold the selected temperature, which is settable.
Glad you found an iron to get you by, Will. I can offer that if you get accustom to checking your solder joints with a lupe or strong magnifying glass you will teach yourself a lot about how it is working for you.

Anyone want to comment on this statement about this brand of silver solder? I realize there is some marketing going on, but I can't say if this is bollocks or not. I am simply a satisfied user of the product.

"Some of the best connections are soldered connections. The problem is only one type of soldered connection is truly a joint, most are as the word states, a connection. Many solders, such as the popular 60/40, are a slurried mixture of Tin and Lead. In making the joint, the Tin/Lead mixture melts, but as it solidifies it does so one metal at a time. It goes into a slurry state where one metal is liquid and the other is very small solid particles. Next, the other metal solidifies, and creates a multitude of small connections. This type of connection is not particularly favorable or permanent. When a phone company had to use this type of solder on their main frames, every joint had to be reheated once a year to insure reliability. Even then, the "cold joint" was a common occurrence. Noisy or open joints were the main cause of failure in early printed circuit boards and electronic equipment until sometime in the mid-sixties or early seventies. Then it was learned that eutectic joints were perfectly reliable. By the mid-seventies or early eighties most electronic equipment was being soldered with Eutectic solder (63/37). The reliability of printed circuit boards went up nearly 1000%, and solid state audio gear began to sound almost tolerable. Today, all printed circuit boards use Eutectic solder. The melting point of a Eutectic solder is lower than any of its component parts, so there is no slurry state in these solders. They solidify as one creating an actual solder joint. The only wires used in high-end audio are Copper and Silver, so George Cardas developed an ultra pure Tin/Lead/Silver/Copper eutectic or Quad-Eutectic solder. This solder is now used in the vast majority of all high-end cables and equipment. Properly done, Quad-Eutectic joints reliably provide the best sound with the lowest noise and contact resistance. (The above was taken in part and paraphrased entirely from George Cardas' paper Soldered vs. Crimped Connections). "
I use Cardas Quad Eutectic in all my work. It flows and works beautifully and produces great looking solder joints. The newer Cardas solder without lead doesn't seem to work as well. I would try to get the older "Quad" formulation.