Brazing 4130

[mofosheee]

Hello again forum

I'm trying to step up the appearance of my brazing of 4130 chrome moly (approx 1/16") sheet and tube.
The appearance and results of my practice brazing on stainless is rather epic. No so much on 4130. My finished product shows room for improvement.

For brazing 4130 I'm using; 1/16" (sometimes 3/32") 2% thoriated electrode, 60 ish amps, proper pre and post flow and SiB rod
Is there someone out here in forum land who can relate to me what has worked for them?
Thanks again!

 

[jwmelvin]

It'd help to see your stainless and chromoly results. I'm no expert, but that would give people something to comment on and would enrich this thread.

 

[rwm]

I have said this in other threads but I have never had good results with TIG brazing. The results looked good but were weak and failed on destruction testing due to melting of the base metal and it mixing with the braze filler metal. I would love to see some of your results and especially if you stress tested them. I personally have gotten much better results (mechanically stronger joint) brazing with OA or Oxy Propane. I used SiB rod on chrome molly tubing with very strong tensile strength.



These joints were oxy propane brazed and see a lot of tensile force in use. They are still intact. Ignore the TIG welds at the top of the image; those are factory welds.