Tooling up for silver soldering

[erikmannie]

Hi erikmannie,
I'm not just being ornery but again I have to disagree, the reason being I had a MAJOR disagreement about this some 30 odd years ago with the manager of the local vehicle testing station who failed a friends mini chopper motorcycle because he had Bronze welded the frame together. I should note that my friend had a business building custom racing bicycles and was well equipped with a vapor-flux unit, frame jig etc and very experienced,( he was the one who put me onto Castolin products). I got involved as he knew I had some literature to back up his claim the motor bike was safe.
Upshot was the manager chucked my books on the floor and called both of us nasty names. A business acquaintance at the time was the national manager for Reynolds Tubing Company and I got him on the 'phone. Testing station manager told him he was an idiot.
Result was testing station guy lost his job a week later. Reynolds Tubing Company specifically state that Brazing with a slip joint or Bronze welding is the preferred method of joining their high strength tubing as it does not affect the UTS or temper like fusion welding and that with Bronze welding the fillet provides more strength by spreading any forces over the joint.
Somewhere I have the Reynolds Company's 'Handbook of steel Tubing' and could scan the relevant pages.

Bronze not having enough strength? There are many types and many of the Admiralty Bronzes in particular make most of the common steels look like 98 lb weaklings. Bronze Lloyd's Register marine rated screws and bolts are expensive for a reason and tougher than nails.

At the end of the day as long as a joint is well designed and properly made it will most likely be stronger than the surrounding material and isn't going to break and that is all that matters.

Yes, brazed or welded properly, the joint will be stronger than the base material.

 

[Dabbler]

I have tried TIG brazing with very poor results!

I'm curious too! We'll see what I get: I usually silver solder (with oxy acetlyene) instead of braze, and that works fine...

 

[royesses]

I set my tig on AC for silicon bronze for the cleaning action. Here is video from Jodi of Welding tips and tricks web forum:

Roy

 

[NortonDommi]

For Propane/Mapp usage I would also highly recommend TS8000.
I looked for that Meco Midget up here but no luck, other than Meco, I have heard so much about another torch called HENROB 2000, it is supposed to be light weight, throws a lot of heat and also saves gas, I think the basic model is around $300 USD ,I think it looks a bit too big and uncomfortable, this is a video on a few good torches, he mentions the Meco and likes it a lot.

I bought a Henrob a couple of months ago. Had to make new hoses as we use a different fitting than U.S.A. I wouldn't call it light but the weight is in a small package. Takes a bit of getting used too after years of a full size conventional unit but I was amazed at just how easy it is to use and most times no flux necessary! The smallest tip is fine for jewelry and the No.3 I have welded 3/8" Cast Iron. I find they cutting a little awkward mainly because of the tip distance and I have a few decades of cutting with a conventional torch and a guides when necessary. Sure I'll get the hang of it. Very impressed with how frugal on gas it is.

 

[rwm]

Jodi has another video where he destruction tests TIG brazed joints. Pretty weak. I think the problem is that if you get ANY melting of the base metal you get brittle inter-metallic alloys in the joint. Theoretically, if you could get no melting of the base you should have the same result.
Robert

 

[stioc]

I have pretty much the same setup as @francist. I use 56% silver Harris filler ($24 on Amazon) because the more silver the lower the melting point. The idea is the part has to be hot enough to melt the filler. Basic propane, a couple of firebricks and it's plenty strong for joining small household parts. Cost about $35 if you already have a propane torch. By all means get a victor portable oxy/acyt setup if you need it.

I have a TIG, MIG and Stick but for small stuff why break out the big guys? It's like why break out my plasma cutter if a few licks of the cutoff wheel will do the job or why break out the SnapOn Verus if the Autel can do the job, or why break out the CNC mill if the 3D printer can mange a part or why break out the Gibson if the Yamaha can play the tune stuck in my head. OK enough humble-bragging for a while, it's the cabin fever!

EDIT: A good, short read on silver soldering vs bronze brazing http://www.thewelderswarehouse.com/blog/silver-solder-braze/

 

[rwm]

Stioc makes a great point about silver solder is the melting point. The lowest MP silver solder is the 56%. If you go with a lesser Ag concentration like 45% the MP is higher and you may need a hotter flame or a better torch. For straight propane or MAPP I would only use the 56% and only for small parts.
Robert

 

[dbb-the-bruce]

So I kinda started this thread and then charged off and got distracted.....
I ended up with a small/medium air/acetylene torch. Got all the larger tips that it can handle.



I'm getting better at the solder/braising thing. Only on my fifth or so attempt at building a cube and getting better. Here is my full "hot table":


Six different types of solder, barrier flux, flow flux, pickle pot, third hand, multiple hot pads, a cool touch to light your torch thingy....
And also got a bunch of enameling to mess around with.
Sorry this isn't much about machining, but my SouthBend 9 is in the background, and there's a mini-mill off to the right.

Thanks so much for all the good advice.

 

[rwm]

I love it! I wish I had space to dedicate to something like your bench.
Robert

 

[dbb-the-bruce]

I love it! I wish I had space to dedicate to something like your bench.
Robert

It's also my dirty bench - teardown and clean up. And in the very distant past, it was my kitchen table!