Welding Tips and Tricks

Hi I got a job making some aluminium tool boxes for a guys new truck, they are 2meters 400 long x 1.4 tall. I'm having trouble welding the two halves together over the 2.4 I'm getting quite a bit of distortion. I'm not clampingit I'm letting it move around. I've done this before and got little distortion but it was like half the size. I'm only welding like two inches at a time then I let it cool and go again. Any help greatly appreciated.

I'm certainly not a pro but things I've seen work before and might be worth trying...

Can you back it up with something to control the heat?

Have you tried pre-heating before welding?

Have you tried to anneal the alloy first? (not sure what grade you are using so it might not matter)

Good luck,

Andre B.

If you're not going to clamp the two halves together, you really ought to consider placing tacks every several inches along the entire lengths. This will help lock it in and prevent the sheets from distorting away from each other.

Do you have any internal structure inside the box? I usually tack every few inches to limit distortion, is this 6061 Diamond plate?

Thanks for the replies everyone. I did put tacks every two inches or so but it really seemed to make it worse. What I'm doing is turning it over and welding the other side which seems to help but not really great. I also tried putting a piece of10mm thick plate under it as a heat sink but it was painful moving cause it's only about 9 or 10 inches long. Anyway it's nearly done done now. I'll try and post a pic. Again thanks to everyone who made suggestions I appreciate it.