warping. How to stop it?
 

How can I stop this warping? Are the welds too hot? Do they look ok? I welded then sand blasted then welded abit more, thats why it looks burnt.

I was thinking about clamping it to a 15mm steel plate. But will it work?



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figured out how to do the pics now

Tis difficult to aviod some distortion on this type of weld

I kept distortion to the very minimum by just tacking the square tube to the plate, I didn't fully weld untill the whole upper mounting assembly was all in place.

The only things I welded fully before assembly were the weld nuts & shock brackets.

The shock bracket does hamper things when fully welding in situ but with the right Mig welder set up, a meaningfull weld is possible :)

Looking at that top picture, have you fully welded both sides of that square tube ?

Yep both sides are fully welded, should I of done that? I'll give it another go but bolted and clamped to a thicker plate. If that doesn't work I'll just tack it like you have done then.
Do the welds look good enough? I know it's difficult to say without testing. But should there be abit more wire going into the weld?

Like you say, it is difficult to inspect a weld from a photo but I don't see anything that would have me unduly worried & judging by the distortion, you have managed to get some decent heat into the welds :)

Clamping to a plate may help a little but it will still spring when you release the clamps.

If you turn the welded plate over & find that the mill scale has blistered or the surface above the weld has wrinkled .... It is a good general indication that the weld on the other side has made good penetration & all is likely to be well ;)

You only need to weld up the one side of the square tube ( Bracket side ) The opposite edge can be welded to the triangular plate that forms part of the top mount.

hi
A method I used to use when I worked at the shipyards was this :-
where distortion has occured due to a straight weld, turn the item over then heat the back of the weld (oxy/prpane or oxy/acety) and as you move along the length of the weld cool it with water a couple of inches after the torch the metal then bends back toward the heat source effectively straightening it.... this is called heat line bending