TIG Braze problems on cast iron

[MountainBuck]

Here is a cast iron (most likely) chuck that cracked and was fixed but not well enough.

I've decided to make it into a welding positioner by brazing a 3/4" hot rolled pipe to it to make sure it cannot be chucked into a lathe ever again.

Cleaned all parts, angle grinder wire wheel, then acetone wipe on all parts and silicone bronze 1/16". DCEN tig starting at 30 amps but kept cranking it up and ended up at about 50 amps. 20 cfm pure argon. Also preheated the cast iron with propane torch.

But could get any better than this goat droppings of a weld!

Anyone can tell me what when wrong??

Only thing I really wonder is that after I was done, it looked "sooty" and hit it with the wire wheel and it looked the classic bronze color.

Under the helmet I kept moving forward but the filler metal would drift back into the last bead and continue to bubble up.

My gut said a flux might have helped more evenly wet the base but never heard of that with tig.

I feel that 50 amps was about the most I want here because I was starting to melt the base cast iron at that.

Don't think I'll "fix it" cause it will hold parts and such but I would like to be able to weld better than this!

 

[Shield Arc]

Next time buy some of this A2 Aluminum Bronze Tig rod. Don't use enough heat to melt the base metal. Heat the base metal just enough that the Tig rod melts into the base metal. Real easy to run!
1/16" A2 Aluminum Bronze Tig 36" Rod - 1 Lb - AWS A5.7 ERCuAl-A2 | eBay

 

[airrj]

Shield Arc,

Can you explain a bit when you would use Aluminum Bronze and when you would use Silicon Bronze? I have a pound of Silicon Bronze and I have used it a few times with good success for light duty applications, and I have read about both AL and Sil-Br but the piratical difference still eludes me.

Thanks. R.J.

 

[Shield Arc]

R.J. this is from the eBay ad for aluminum bronze.
Washington Alloy Aluminum Bronze A2 is a copper based filler metal containing about 1% iron used for gas-tungsten arc welding and gas-metal arc welding of
copper, copper-nickel, brass, bronze, steel, galvanized steels and also cast iron. Most common applications would include marine maintenance and repair, ship propellers, pump housing, rigging jacks, piston heads, bearings and excellent for build-up or overlaying wear/corrosion resistance applications. Combinations of Copper or Aluminum Bronze base metals to steel are very common with this filler. Exhibits high mechanical properties and hardness.

In the 1970s I worked out of the Sheet Metal union. We used Silicon Bronze in our Mig welders to weld galvanized sheet metal. Seems as I remembered we used 98% argon, with 2% oxygen for gas. I tried to run every thing vertical down hill.
Really this is over my pay grade. I was a structural welder, building bridges, container ship docks, and ferry docks. We ran a lot of self shielded flux core wire.

 

[airrj]

Thanks. I have heard about both, but I am trying not to have a sample of ever TIG wire ever sold hanging out on my bench. I'll stick with the Silicon Bronze until I use this package up.

 

[yomax4]

ALB is a very cool product. I used to sell a ton of it when I worked for JW Harris. We sold ALB1 for overlay or repair of worn bearing surfaces etc. And ALB2 for joining. Tig and Mig. Bother were very popular on the coasts due to salt water corrosion..
Read up on it and Silicon Bronze. All are under utilized products.

 

[MinnesotaDaveChalmers]

Next time buy some of this A2 Aluminum Bronze Tig rod. Don't use enough heat to melt the base metal. Heat the base metal just enough that the Tig rod melts into the base metal. Real easy to run!
1/16" A2 Aluminum Bronze Tig 36" Rod - 1 Lb - AWS A5.7 ERCuAl-A2 | eBay

I found it easy to tig braze with Alum-bronze as well. Enough heat and it kind of wicks into the surface.