Silver Solder VS Lead Solder

[kathy45]

I'm going to have a slide and leadpipe re-soldered and a 3rd slide stop added. I've talked to several technicians who use 60/40 lead and tin, and another that uses silver solder. I'm leaning toward the silver solder, especially if it will look good when finished and I won't need to re-plate.

Any cause why not to go with silver solder? My understanding is that it's actually stronger than lead but harder to work with. I have a very experienced tech that's recommending silver solder so quality shouldn't be an issue.

What are the pros and cons of lead and silver solder especially quality, fit, finish, and playing characteristics if any? I'm not really concerned about silver being harder to work with since I'm having someone do the work for me.

[IanB]

I guess you are talking about a musical instrument?

Silver solder usually refers to a stronger solder used for mechanical joins (compared to lead solder which is soft and relatively weak). However, silver solder has a higher melting temperature, which means the parts have to be heated to a higher temperature to make it work.

When I have seen silver solder used on brass it generally required the parts to be heated almost to a dull red color, which caused tarnishing and oxide formation and required significant cleaning and polishing afterwards. This is an area where you need to make sure you are consulting experts in musical instrument repairs who know exactly what they are doing. This forum is not that place, IMHO.

[IanB]

In case you are interested, here is an example of silver solder being applied to join some copper and brass parts.

If you are asking questions like fit, finish and playing characteristics then I think you really need to go to a musical instrument forum and not an electronics forum...

https://youtu.be/M9c4civZYvs?t=4m24s

[David Hess]

If you are referring to low temperature silver solder like the common Sn62Pb36Ag2 which is used in electronics, then it should always be used in mechanical applications in lieu of Sn63Pb37 or Sn60Pb40 simply because it is a lot stronger.

Silver brazing requires a much higher dull red temperature using a solder which is about 50% silver.  This would be required for any joint which requires mechanical strength.

[Gregg]

There are a number of low temperature lead free soft silver solders available.  I personally like the Allstate 430 available in the US, but with some comparisons to other brands, I'm sure other manufacturers offer almost identical solders.  It melts at 430 degrees F or 221 degrees C and is considerably stronger than most lead alloy solders plus it remains shiny silver colored similar to 316 stainless steel.  Most high temperature industrial silver braze alloys are slightly golden in color, but there are a lot of alloys that the jewelry industry uses to mimic the colors of silver or gold. 
Here is a link: 
http://www.esabna.com/us/en/products/index.cfm?fuseaction=home.product&productCode=1107
Stay Brite also makes a variety of lead free soft silver solders.