Silicon Bronze Tig Troubles

[racer-john]

@ Dave Z.
Have you switched to the C25 tank for your TIG?

[Dave Z.]

no...but as I understand straight Argon is the proper gas...Argon Helium mix if you want to weld hotter..I been doing practice beads and concentrating on being steady, arc length, and keeping the rod where it belongs. I think I rushed into my tank project to fast. Hopefully tomorrow Ill get more practice in...I think I run beads in my head even when I'm not doing it for real!

[qkiss]

Silicon Bronze using TIG on Stainless Steel header flange. Machine set on DC using straight Argon. It flows vary nice and have never had any problems with it.




The Bronze is more forgiving with vibration cracking. Weld inside the flange and Silicon Bronze the outside.

[Dave Z.]

I can only hope one day I can lay it down like that!

[Dave Z.]

Steve..Is it easier to lay a nice fillet weld on something as thick as that flange vs. 16 or 18 gauge sheet steel? Seems I over heat the base metal and my weld flows out like lead solder. If I do practice welds on a flat piece and get a "bead" it looks more like a worm than a weld. Not to cold but no "dimes". I know...get pics...maybe I can figure out how to resize pics also to post here...

[crystallographic]

Originally Posted by SoCalShaper

If you soaked the bronze through. That's your problem. Silicon bronze is used for tig brazing which just like brazing with a torch is not welding. You should only heat the base metal enough for the bronze to bond to it, not melt together. When you first welded it pin holes or not it's joined, the bronze should have been only to cover it. You shouldn't melt the base metal and bronze together. And my two cents if I were you I would practice till I could get a leak proof weld, and forget the Silicon bronze altogether. Brazing has its place in welding but I wouldn't want to use it to fill holes on my gas tank. Good luck and don't give up, you'll figure it out eventually.

Kyle

Excellent point, Kyle.
Thanks for pointing out this essential distinction.

[qkiss]

Originally Posted by SoCalShaper

If you soaked the bronze through. That's your problem. Silicon bronze is used for tig brazing which just like brazing with a torch is not welding. You should only heat the base metal enough for the bronze to bond to it, not melt together. When you first welded it pin holes or not it's joined, the bronze should have been only to cover it. You shouldn't melt the base metal and bronze together. And my two cents if I were you I would practice till I could get a leak proof weld, and forget the Silicon bronze altogether. Brazing has its place in welding but I wouldn't want to use it to fill holes on my gas tank. Good luck and don't give up, you'll figure it out eventually.

Kyle

You need to fully understand what Kyle has mentioned about it being a brazing process and not a welding process. After the bronze puddle is established it is manipulated with torch and filler rod to stick and more or less flow on top of the metal rather than penetrate through the base metal.


The expanded metal tread on the pedal pad is only .020 thick and .030 wide. The trick hear is to run the bead on the pedal pad and wash the bronze puddle over and pick up the expanded as we go around the perimeter . Hope this helps you visualize the process.

[Dave Z.]

I guess with trying to make a wide cover of bronze I over heated to whole area. My intention wasn't to melt both together but after it was all said and done that's what I had. I didn't know that was possible until you guys said its what I did. What I practiced on today is a length of 3 1/2 inch by .065 wall tube that I steel welded a pipe fitting and two ends onto. Now I can put a few psi in and check for leaks. I'm going to use bronze on it also. I can keep frankensteining it to practice. To me....its a good idea for a practice piece...

[qkiss]

Oh ---- I forgot to mention the above stainless steal header flange is 3/8 thick and the tube is 18 gauge .050 stainless.