Hello everyone!How critical are the tolerances over the whole length of the chassis,as I have just started to fully weld my chassis, and I have noticed a lot of distortion.
The chassis is clamped to my work bench, and after welding the floor section and allowing it to go cold I have released the clamps to find it has warped slightly from corner to corner by about 20mm.
How critical is this, and most importantly will it effect handling?

are the susspension brackets on ? if not you can position them to suit your "warp" if you know wot i mean, a local fabricator who knows his job should be able to put some heat in the rite places to pull some of the warp out too.......no pulling n bending, just heat in the rite place's
My self i would think 20mm is a fair bit... others........ ?

No, the brackets aren't on yet and I think I may be able to compensate by positioning them acordingly.
I suppose my only other option is to try to persuade it back with a big hammer and then go over the whole chassis squaring it back up?
I have only welded the floor section and all the rest is tack welded so maybe all is not lost.

if it's not fully weld'ed yet, you could, with shrewed welding pull it back into shape, get some one local who is an experienced welder to take a look, he will know which welds to put down 1st to get the desired result, to check theroy out, weld to bits of scrap togethor, watch it move as it cools, you will see it with the naked eye...

Oh dear! - the old warpage.

Here are some of my experiences if it is any help.

I leapt into my chassis with great gusto and forgot what it said in the book about only tack welding: Result - one banana shaped chassis floor!

However still convinced that I need a good rigid base I re-built with tacked joints whilst thoroughly clamped down turned it over and tacked again before repeating the process with full welds - it was flat and has remained so. I don't know if this helps to reduce warping in the fully welding stage but it might.

I have also welded the diagonal braces in first now I have started to fully weld, in the hope that this would help - so far so good whether that has anything to do with it or not I don't know.

Finaly - as it says in the mighty tome I am welding alternately accross the chassis and also alternately across the sides of each joint.

As I have said so far so good and it hasn't been clamped to the table during this process beacuse of constantly turning it to weld around all sides.