Help with full penetration on 12ga.

[BOBBYLEE Junior Member Find all posts View Profile Close BOBBYLEE]

There **** bent on tig. So not really sure how its going to turn out. I'll mention gaping it and beveling it for the mig process. I'll post back when the works arrives. Thanks for everyone's replies.

[piniongear Senior Member Find all posts View Profile Close piniongear]

BobbyLee..
Since they INSIST that it be Tig welded about the only thing you can do is remove the galvanized coating.

So if it were me I would use an 80 grit flap wheel on a 4-1/2 inch grinder.
Grind both sides of the 12 gage material to remove all traces of the zinc.
Be careful with the grinding so you do not reduce the thickness of the 12 gage material any more than necessary to get the zinc off.

Then wipe down all surfaces with lacquer thinner.
I bet the material will now be ready to accept the Tig. Maybe not as perfect as clean metal but I bet you get full penetration so that it is leak proof.
And hopefully they will be satisfied with your effort you have made.
Let us know how it turns out.
pg

[snoeproe Senior Member Find all posts View Profile Close snoeproe]

Tig is not the best procedure for this job. It would be my last choice to be honest.
12g is just a hair less than 1/8" thick material. This can be welded with 3/32 stick rod with no issues at all. 6010/11 will cut right through the galvi as stated. Myself, I'd remove some of the galvi and weld it with 7018.
I weld a lot of 12g hot rolled steel sheet (non galvi) with 3/32 7018 stick. To achieve full pen with a tight fit up (no gap) I have to weld hot. A very slight gap will allow full pen with a little less heat.
The problem with trying to remove galvi prior to welding is you never get all the galvi removed. This is where welding with stick is your friend and tig is not your friend. Since you only get one pass with this material, stick would be my choice.

[BOBBYLEE Junior Member Find all posts View Profile Close BOBBYLEE]

Well, we got the sheet metal in. It wasn't to bad, we ground the zinc off about 1" on both sides of where it was going to be welded. Had to Tig it, it was the procedure they wanted. The inspector is supposed come tomorrow. We'll see. I didn't think it turned out to bad for what it was. Tried to upload pics but it said the file was to big.... Any thoughts on that?

[piniongear Senior Member Find all posts View Profile Close piniongear]

Thanks for updating us on how it went. Glad to hear it turned out OK.
I cannot recommend a way to reduce the pic size, but I am sure someone here can offer a way.
I would like to see what you did.
pg

[ryanjones2150 Senior Member Find all posts View Profile Close ryanjones2150]

What I ended up having to do, after many frustrating attempts, was transfer the pictures from my iPhone to the desktop, open them in Microsoft paint and use the resize tool (in pixels). Seems like 700 the long side and the other one adjusts itself. To me it's a pain in the rear. Which is why I don't do it much.

[Ltbadd Senior Member Find all posts View Profile Close Ltbadd]

What I ended up having to do, after many frustrating attempts, was transfer the pictures from my iPhone to the desktop, open them in Microsoft paint and use the resize tool (in pixels). Seems like 700 the long side and the other one adjusts itself. To me it's a pain in the rear. Which is why I don't do it much.

I'm just the opposite, give me a desktop to work with, why anyone wants to mess with a small screen and limited controls but I digress. It is easier to set the image size on your phone before (of course!) taking pics you want to upload, just select a much small size.

[BOBBYLEE Junior Member Find all posts View Profile Close BOBBYLEE]

It's pissing me off, i can't figure it out!!!

[BOBBYLEE Junior Member Find all posts View Profile Close BOBBYLEE]

Ok maybe I'll try that tomorrow.