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Tig braze or not

Posted: Sun Jun 26, 2022 11:18 pm
by dunkster
Doing a little resto on a mower deck here. Needing to weld in two of these shield gizzy's, front and rear:
DSCN0984.JPG
DSCN0984.JPG (4.32 MiB) Viewed 3871 times

Deck itself is around .060/.070 thick and shields are .075 thick. Came close to burning them in today w/ some ER70 till I thought about what the back side (top of deck) will look like after the fact and thought this might be a good candidate for tig brazing w/ some Aluminum Bronze. My goal is to avoid or at least minimize the distorted crowning affect that always seems to happen on the backside of thin T joints. I really just want to hit it with a DA afterward and call it a day.

I ran a lot of SiB some 20+ years ago, but that was on copper pipe pie cuts, so I have no idea how a carbon steel T joint will react to it.
Any input on that and maybe some heat #'s to start with would be greatly appreciated.

Re: Tig braze or not

Posted: Mon Jun 27, 2022 7:01 am
by ESENTI
map gas silver welding 40% silver

Re: Tig braze or not

Posted: Mon Jun 27, 2022 9:58 am
by cj737
You can TIG weld it with ER70 and some proper heat control. Or, use SilBr and TIG braze it. Steel-steel joints are suitably strong with SilBr.

But the deck has to be super clean for either process.

Re: Tig braze or not

Posted: Sat Jul 16, 2022 6:59 pm
by dunkster
Sorry guys, been a while I know...life has a bad habit of doing that.


At any rate, I've since picked up some 1/16" AlBr filler. And as always, my results on scrap resembled absolutely nothing like what shows in Jody's videos. So onto next option.


I got to thinking about cj737's comment on "proper heat control" with some er70. My machine does have a pulse feature but have never really invested the time in messing with it...until today. All I can say is hell yeah! Ran some tests on some scrap 14ga left over from the shields I made and was both super surprised and pleased with the result. Backside warpage was virtually undetectable and had zero burn thru on backside as well. Super happy. I'll try a few more tests before the real deal to see what more of my parameters are and go from there. Hopefully it'll be something worthy of posting pics.

Thanks guys.

Re: Tig braze or not

Posted: Sun Jul 17, 2022 6:06 pm
by Gdarc21
Yeah its like that. Its easy to get busy working skating coding etc. There is always some activity.
I sure you are aware that aluminium bronze on run on ac. Due to ally content. Silicon bronze on dc and can run on ac aswell. Usually only albr on ally kinda jobs. Silbr on steels coppers etc. Gas lens helps lots. Hope you get there in the end
I start at around 50 amps dc for 1.6mm filler silbr. 7-8ltrs per min argon.