Welding Tips and Tricks

Hello!

I recently created a 1.5"x1.5"x0.125" angle iron frame to mount a ventilation fan to a connex container. I added 1/8" plate "walls" to the frame to give me some depth, given the corrugated nature of the construction of the connex. With that said, I TIG welded the frame itself, and it was very flat and square. I then stick welded the "walls" for expedience, and (like a dummy) I assumed because the frame was already welded and square and flat, that it wouldn't distort much. I was VERY wrong!! The frame is now bowed by probably 1/2" from corner to corner, and two corners are about 1/4" out of square.

With all of this, is there any way to save this thing, or do I need to just start over? Given the cost of metal, I really hope I can salvage this thing.

Thanks in advance!

This is one of those things with welding that is useful and horrible, when you get used to predicting.
You can, using a stong clamp put packers under the edges and pull it down with the clamp. Its important to note that the bend moment needs to be found. For instance a beam that is 6 foot long and looking curved may only be actually bent on 2 to 3 spots and they are usually welds. So give a bit of space either side of it and pull it down.
Adding heat from a gas torch even a plumbing one will help to localise and control the repair with out making worse.
1/8 inch could even be secured to bench and hammer-assisted
Photos, for us, of how it looks would help too

Having just modified a few of these containers for the Navy, and building one for my eldest, I will wager that the frame distorted because when you cut the corrugated sheet, you did not tack in stabilizers from side-to-side. Without a “restrictor” the corrugated name will billow and bulge from the welding.

Can you fix it? Yep, cut out the frame, tack the stabilizers in, then tack and weld the frame back. You can test the flatness of the frame once cut free. You should be tacking that frame around the perimeter every 12” or so until the side panels are secure and stiff. Once welded and everything is cooled fully, cut the stabilizers out.

@Gdarc21

I'll see if I can get some pictures of it, but I'd be embarrassed to post them! LOL

I was using a new welder and trying to feel it out. It was real amateur hour... too cold, way too hot, 3/32 seems too small, 1/8 seems too big, etc., etc.

Are there any tricks, without having a 1/2" thick fixturing table with 50 clamps, to prevent this kind of thing? I've seen a ton of Jody's videos, and he addressed distortion, but I just don't have enough experience to know how much something is going to move based on filler material, size of bead, etc., etc. Also, what is a "packer"? Apologies for my ignorance.

@cj737

I have not even attempted to install this thing in the container yet. It is so bowed that the fan that I want to install on this thing wouldn't even come close to sitting flush on the "flange" of the frame. When you talk about adding stabilizers, are you referring to putting them on the frame itself or on the corrugated wall of the container?

This is my first time trying to "fabricate" something square. I have done a ton of repairs and making small little gizmos, but this process of trying to make something square has been kind of a nightmare.

Thanks for the input, folks!

I see, the frame loose when welding on the “walls” racked your frame. You don’t need to fully weld the seam if that’s what you’ve done when adding the sheet/plate to the angle. Doing so will warp your frame. Stitch welds about 2” long every 12” is ample to hold it together.

But when you weld things like this, yes you need clamps. Kind of like an orgy; the more the merrier. But mostly patience, skipping around the perimeter evenly and avoiding excessive heat build-up in a single area is the best trick.

Stabilizers are from front wall of Connex to rear wall. This holds the corrugated panel in place once you cut it open and weld in the frame. Else the walls will taco and curl on you.

cj737 wrote: ↑Thu Apr 21, 2022 3:15 pm I see, the frame loose when welding on the “walls” racked your frame. You don’t need to fully weld the seam if that’s what you’ve done when adding the sheet/plate to the angle. Doing so will warp your frame. Stitch welds about 2” long every 12” is ample to hold it together.

But when you weld things like this, yes you need clamps. Kind of like an orgy; the more the merrier. But mostly patience, skipping around the perimeter evenly and avoiding excessive heat build-up in a single area is the best trick.

Stabilizers are from front wall of Connex to rear wall. This holds the corrugated panel in place once you cut it open and weld in the frame. Else the walls will taco and curl on you.

Thank you for the information. Yes, I was fully welding the seam to try to make it as water tight as I could. I had not thought of welding on stabilizers, but what you are saying makes sense! Do you have any recommendation for how far away from the weld site to place the stabilizers? I'm thinking that if I use angle, I might be able to clamp on some chill bars to at least help in the areas where they make contact.

I grabbed a couple of pics to show how bad the bow is…

Yeah, that’s pretty bad. I might suggest eating the expense and getting some 2.5x2.5x3/16 and start over.

Cut that other thing up and sell it as scrap to recoup some money. Your time to “repair” that frame will be vastly more than the cost of newer material you only have to miter and corner weld.

cj737 wrote: ↑Fri Apr 22, 2022 7:58 am Yeah, that’s pretty bad. I might suggest eating the expense and getting some 2.5x2.5x3/16 and start over.

Cut that other thing up and sell it as scrap to recoup some money. Your time to “repair” that frame will be vastly more than the cost of newer material you only have to miter and corner weld.

Ugh... I was afraid of that. I guess I'll order some more angle. Thanks for the input.

cj737 wrote: ↑Fri Apr 22, 2022 7:58 am Yeah, that’s pretty bad. I might suggest eating the expense and getting some 2.5x2.5x3/16 and start over.

Cut that other thing up and sell it as scrap to recoup some money. Your time to “repair” that frame will be vastly more than the cost of newer material you only have to miter and corner weld.

Had to get 3"x3"x3/16" angle, and this time I coped the corners vs mitering them. I also, switched to using pulse-MIG on the joints, rather than stick... which I was using before. Throw in a dozen clamps, and I was able to get a pretty decent frame. Thanks for all of the help with this issue. I appreciate it!