Brass oak leaf cluster

Repousse & Chasing | | | |
Brass oak leaf cluster

This is my latest and unfinished project. All that remains is to solder all the indiviual leaf stems to a common branch stem (gulp). I'm mostly worried about previous solder joints coming undone, any helpful commens would be appreciated. There are additional pictures of this and other projects of mine at:

http://s810.photobucket.com/albums/zz24/mark-gallo/Repousse-Chasing/

Thanks for your time, enjoy!


Rich Waugh's picture

If you're going to hard

If you're going to hard solder them using something like Sil-Fos rod and an oxy/acetylene torch, you should have no trouble at all. Brass and bronze don't conduct heat so quickly that you'll have previous joints come apart when doing the subsequent ones. That might not be the case if you're planning to use soft solder, though. Using a torch that is not hot enough, like a propane hand torch, can mean you spend too much time heating and the heat conducts too far from the intended joint. To prevent this, you can add damp clay or wet asbestos around the stems next to your solder joint to keep the heat from flowing. There are special proprietary compounds like "Kool Jool" that jewelers use for this sort of situation, but you don't need to get that fancy.

You can do it.

Rich


mark gallo's picture

Rich Thanks for the wet

Rich

Thanks for the wet clay/asbestos tip. I'm still in the low dollar hobby range so no oxy/act is available. To date i've used 445 liquid point acid core solder with a very small flame propane torch. To prevent heat transfer I've used rags soaked in ice water and it's worked.

I'm considering using low temp 63/37 circuit board solder for these last joints. Something like Kester 44 Rosin Core Solder 63/37 .031".

Mark


Rich Waugh's picture

If you're forced by

If you're forced by circumstances to stick with the low-melting point solders, I'd suggest you look into one of the silver-bearing solders such as Harris' "Stay-Brite" or similar. They add a percent or so of silver which raises the melting point up fifty or a hundred degrees, still easily attained with your torch set up, but it does increase the joint strength considerably.

One of the problems with low-temp solder is that it really is intended for use in either no-load or low-load situations, or for uses such as plumbing where there is a large surface contact area to distribute stresses. Your wire-to-wire joints have very little contact patch area but could be subject to some stress so I'd take advantage of the silver-bearing solder. It works the same as regular lead solder but you will want to use the proper liquid flux with it - I don't believe it is available in a flux-cored version, though I could easily be mistaken about that. Ammonium chloride (sal ammoniac) is the active ingredient in the usual flux for silver-bearing solder.

Your rosin-core electronic solder is intended for use on clean copper wire/terminals, and is not particularly good at removing oxides. I don't think you'll find it very satisfactory for your purposes on this project. You really need an acidic flux like the sal ammoniac or tinner's flux.

Hope this helps,

Rich


visitor's picture

Rich, thanks for the tip,

Rich, thanks for the tip, the silver solder worked great!