Welding Tips and Tricks

Hello All,

Working on a door panel. The material is steel 1" sq. tubing .083" wall frame that has 14 ga. panel inserted in inner dimensions of frame and welded all the way around ( has to 100 percent sealed). I used 3/32 cer., #7 cup, stubby gas lens set up. 160 amps with 1.5 pps, 30% peak and 5% background. Used .045 filler mostly and 1/16 filler where I had some larger gaps. I used whatever "chill bars" i could come up, 2 -3 inch welds at a time, allowing time to cool, and moving to different areas around the panel.
My question is - Can you really keep this from warping AT ALL?? The sq. tubing ended up a little wonky. I was able to "persuade" it back, but still not "perfectly" flat. Attached is my first panel, but I have a larger panel to do next - looking for some pointers to help keep it flat and any other constructive criticism.

thanks!
Ty

Another pic of the panel

Looks like you're on the right track, especially with the chill bars. Warping on things like that can be inevitable, though. Only thing I would do a bit different than what I see you doing (at least in the second pic), would be to get several tacks all around the perimeter first (alternating sides often), then do some stitches at the corners and a couple on each side while again alternating sides with each stitch. Then I would weld it out in 6-8" runs...again alternating sides each run. Just the way that I would skin that cat...lots of ways to do it, though.

I would think that would be really tough because it has no constraints in the vertical directions. My gedankenexperiment says you might need a super-tiny "root pass" with 035 filler to really kill the heat input, but that's above my pay-grade.

In this setup with a sheet inside the frame you are fighting multiple distortion effects from heat input to differing tensions in the sheet as the welds cool and they start to pull/draw on the sheet in different amounts/directions.

Welding any sort of sheet metal pretty much inevitably needs some 'massaging' to get distortion out with some traditional sheet metalworking tools like dollies, (shrink)hammers and such to get the tension out of it. Probably fixable, but may be time consuming.

A different setup with a sheet that has 90 degree folded edges and (partially) wraps 'around' the frame and is welded on the outisde edge/back usually has less issues as the bent edges already make it a lot stiffer and the weld distortion is in a different plane from the front sheet.

Bye, Arno.

Thank you all for the responses!

I started this project with 2 goals in mind: #1 to have a nice size project with lots of welding (TIG in this case for practice and learning) and #2 to build my own smoker. Definitely getting a lot of TIG work in and definitely learning things (related to welding) !!!

Spartan - I did tack about every 3 inches around the perimeter but its on the back side of the sheet metal (not visible in the pics). Did the same thing with the larger door panel - clamped down frame and best fit the sheet metal inside the frame and clamped it down. The radius on the tubing corners creates a little more gap than I planned for. Had 1/16" gap at the worst case in some places. Started tacking, going around the perimeter. Got finished and looked back at where I started and now had an 1/8" gap there!! WTH??? That was an eye opener on how much things can move! Figured that the tacks broke/cracked but I don't think they did, just stretched a little ( I think). Needless to say that has been cut apart to try again.

Arno - I understand your comment about the 90 degree bends on the sheet. I will store these thoughts away for future reference!

OK, so the next part of this panel:

I need to now weld 16ga sheet on the other side but it will cover the frame ( flush with the outside dimensions of sq. tube frame. High temp insulation goes in the space between the sheets.

I'm stuck with what I got on the small door panel (the pics I attached), but I have the larger door panel to do. Its roughly 20 by 25 inches. I'm thinking tack in the 14 ga., place insulation, then tack on 16 ga., then commence to welding - working both sides of the panel (flipping back and forth from 14ga side to 16 ga side). Any thoughts on this approach??

Thanks a bunch!!
Ty