Help with full penetration on 12ga.

[BOBBYLEE]

Ok maybe I'll try that tomorrow.

[BOBBYLEE]

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

[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.

[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.

[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

[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?

[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.

[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

[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.

[aametalmaster]

We have some 12ga galv sheet metal that they want welded up with full penetration. They told me to try GMAW which didn't pen at all, 70s hard wire. Then I tried GTAW and that broke it down but what mess. Any suggestion's would be great. Thanks

I was a union sheet metal welder for 8 years. The only way you are going to get full pen is either gap the parts or bevel the edges. Then weld away with a mig and .030 wire. No problem...Bob

[ryanjones2150]

I agree with piniongear. Even when I attempt to tig after grinding off the zinc, I always end up finding a place with some of the foul stuff left. It's really easy I think you've ground enough off and just burnished it back a little. I am not very experienced with O&A outside of cutting and a little brazing, but could be a solution I guess. I'm still leaning towards stick. Any way you can get some test pieces and work through a welding process ahead of time? Good luck my friend. Let us know what you work out.

[piniongear]

Pulsed Tig is not going to make any difference at all.
What you are fighting is the zinc coating on the 12ga steel. That crap boils and then fouls the weld.

Take a piece of 12ga bare steel and it will weld with complete fusion as easy as drawing a line.
Galvanized is never going to be weldable with the Tig process in my opinion.
And like others have said.....Those zinc fumes will make you very sick. Your boss needs to be told this.

[BOBBYLEE]

Wonder if I pulsed Tig it would it work better? The machine is a XMT 304. So they would have to rent or buy a pulse control for it.

[mcostello]

Braze it.

[BOBBYLEE]

Wonder how'd that would work out?