MTFCA Forum

I was going to order some silver solder on line. Can’t really tell by the tiny pictures on my phone, which solder appears as brass? Also, will Mapp gas be hot enough to melt the silver solder? I’m a little afraid to take the big torch to it as this is my first attempt at using silver solder (repairing a crack in a radiator shell).

David I have some extra silver solder thatI have used on brass lamp rims and can send you a few sticks. I use my big torch with a small medium flame, not too hot.
John Kelso
Email me at Firststeaman@gmail.com

I used Harris Safety-Silv 45 as it’s also brass colored. I never tried it with MAPP but had good luck with acetylene and was able to repair a brass horn.

I have often used what I believe is “jewelers” silver solder to make repairs on thin brass parts. It has a low melting temperature and will work with mapp gas as long as there isn’t much mass to the part. I tried another alloy that is used for refrigeration repairs but found that it required too much heat and was difficult to use.

TMiller6 wrote: ↑

Sat Aug 03, 2024 1:48 pm

I used Harris Safety-Silv 45 as it’s also brass colored. I never tried it with MAPP but had good luck with acetylene and was able to repair a brass horn.

I have used the same. Depending on the mass of the part you're silver soldering, propane can sometimes work as well.

Controlling the heat is important. I have purchased a turbo tourch and a jewelers tourch for fine work, a good investment I made over the years.

The key when soldering is heat control no matter which solder you use. You can do a good job with Oxy/acetelyene or a propane hand torch or everything in between. Practice for heat control on an old piece of brass or something similar FIRST before you try it on your part you want to repair.
You mentioned you're trying to repair a radiator shell. If it’s nickel plated shell or a brass radiator it won’t take much heat. Just remember not to get it too hot as too much heat will cause the solder to spread out on your piece. If it’s a steel shell use a brass brazing rod as it will be stronger on the steel than solder. Good luck.

I found it much easier to get a good job if I used solder with the highest silver content, 45% i believe. It flows very well, seems to require less heat, but it does cost way more. The key, as with any soldering, is get the surfaces absolutely clean, and use the correct flux.

Allan from downunder.

Just getting back to the forum...... The shell is one soldering project, it's a '26-'27 brass shell that will be replated. I also have a couple brass horns that need cracks repaired, a brass headlight rim etc. I'm guessing some of the silver solder has a silver color, and some has a brass color. What do I need to get for the brass colored solder? It doesn't matter for the shell because it will be plated, but the other brass pieces will need the brass color.

Silver solder, when polished, is hardly noticeable in a crack in brass. Under the nickel in a radiator or headlight rim it is hidden anyway.

Allan from down under.

schwabd1 wrote: ↑

Sat Aug 03, 2024 10:29 pm

Just getting back to the forum...... The shell is one soldering project, it's a '26-'27 brass shell that will be replated. I also have a couple brass horns that need cracks repaired, a brass headlight rim etc. I'm guessing some of the silver solder has a silver color, and some has a brass color. What do I need to get for the brass colored solder? It doesn't matter for the shell because it will be plated, but the other brass pieces will need the brass color.

TMiller6 gave you the answer.

Oops..... Thanks for pointing that out Jerry, I was focused on the gas used and read right over the "as it’s also brass colored". Thanks, Tom for the answer.

schwabd1 wrote: ↑

Sun Aug 04, 2024 12:08 pm

Oops..... Thanks for pointing that out Jerry, I was focused on the gas used and read right over the "as it’s also brass colored". Thanks, Tom for the answer.

No problem.

It's good stuff! Just be sure you don't get the relatively thin rad shell metal too hot and warp it, as others have cautioned. Also, use the appropriate flux.

Practice on a piece of scrap FIRST to get the heat right you want to use!! No kidding, you’ll be surprised at the difference it can make.

Hi David,
As I understand you have a 26/27 brass/nickel plated radiator shell. You plan to repair cracks in it & have it re-plated. You are looking for a brass looking solder to do the repair with before taking to the plater? I'm thinking you should consult the plater. Plating doesn't always look the same with dissimilar alloys. I found this out when I was restoring antique motorcycles. Even steel parts would show repairs when chrome & cadmium plated. Many platers do repairs ( yes it will probably be expensive but plating is not cheap either)
Craig.