Silver Solder

[Cold Rolled]

I getting into build steam engines. There are countless references to silver solder. I have solder that has silver in it but it is a small percent. How much silver content do I need? If there is special solder for boilers and fittings where can I buy it? Thanks again everyone for your responses.

[SGW]

Small Parts Inc. www.smallparts.com sells various grades of silver solder. They typically melt in the 1200-degree range, give or take depending on the exact alloy. The process is probably more correctly called "silver brazing." Another mailorder source is Brownell's www.brownells.com but Small Parts had a better selection, last time I checked.

The low-percentage silver solder you have, which I assume you can use with a regular soldering iron, isn't suitable for boilers, at all.

[darryl]

There's a lot of solders referred to as silver solder, or silver bearing solder, that are no good for metalworking. Electronics and plumbing, sure. Real silver solder is good solid wire, nowhere near as flexible as ordinary solder. It's not generally found in hardware stores. You won't find it on a tight little roll, like the other solders.

[This message has been edited by darryl (edited 03-28-2003).]

[George Hodge]

C.R.,you can get the silver solder you need at the welding supply in your area.They'll have it in wire or strips of flat sheet,and it will be pretty near pure silver.Get a small jar of the flux at the same place.A propane torch or Oxy/Acet. torch will work great for melting.I have a Halogen heat lamp which claims it will work too.The welding supply should have free instructions on how to use silver solder. Be sure to stop at the bank first,silver is pricey.Ask if Sil-Phos rod is strong enough for what you will be doing. It might be cheaper.

[Oso]

Sil-phos has some problems with certain fuels and longevity. Not what I'd want for a boiler.

See the chaski live steam board, and check the archives. Lots of info.

[darryl]

A small tip on silver soldering- when applying the flux paste, try to 'rub' it on, to work it into the pores of the metal surfaces. I find that it does it's job better, and allows the solder to flow more quickly and evenly.

[Cold Rolled]

Thanks again for the replies! I have order some from brownels. Along with flux and Heat Stop that I have wanted to try. I like dealing with brownels but every time $100 or $200 disappears from my wallet?!?
Also I went to that Steam BB very good info!

[Techtchr]

Musical instrument keys are silver soldered together, and so are the tube and socket braces on brass musical instruments. You can also purchase silver solder from Ferree's tools in Battle creek MI. ferreestools@aol.com

The best tip to give anyone in silver soldering is to make sure the parts (i do mostly brass and nickle)are clean before you put the flux on. It is similar to soft soldering in that the silver solder flows towards the flux, and towards the heat. Dirty parts won't solder.

Another tip for silver soldering, when you are sure you are done soldering, and you want to remove the flux quickly, dunk the part in a solution of muratic acid (diluted)while it is still warm. if it doesn't remove it all the first time rewarm the part and dunk it again.Be sure to rinse the part with lots of water when done. If you are patient, you can just let the part sit in water overnight.

Matt

[Dave Fiscus]

Just read your question about silver solder and can add a little information to the posted replies. Silver soldering is used in jewelry making and is usually called hard soldering. Unlike soft solder which is made of tin, melts at a low temperature, and only sticks to the surface of metal, hard solder is made of alloys of silver and zinc and melts at 1325-1425 degrees F. You melt it with a torch, and it enters the metal making a very strong joint. As another reply mentioned, the metal must be very clean for it to work. It is pricy but very little is used, little chips about 1/8 inch square being most common. You can buy it at any jewelers supply store. It is sold in sheet, chip and wire forms in Easy, Medium, and Hard grades. Easy has the lowest melting point. Art metal workers use it to solder copper, brass, nickel-silver, and silver. Most jewelry making hobby books give details on good soldering techniques.

[Cold Rolled]

Thanks again for the replies. Dave I am going to take your advice and find book on soldering boilers. I tried a test sample piece and failed miserably. I did not have enough heat. I have welded before (gas, tig, mig) and done some brazing. I even silver solder one time, two disks, some wings and a blade made from silver and brass called it Art!?! But I do not currently have an oxy-acetylene torch. I just bought a lathe, see other posting http://bbs.homeshopmachinist.net//Fo...ML/001070.html so I can not buy a torch for a while. I will borrow one next time I am ready. Thanks again.