Warped metal :(

[vijay]

Hi all,

Just wondereding if there's anything can be done if the metal has warped while welding. Some 1mm steel had to be welded onto my car and the guy went a bit mad with his welder (so called expert). He basically welded the whole thing in one go withought letting anything cool down. From what I remember reading on the forum, you have to spot weld in stages, letting the metal cool before starting again, is that right to stop it from warping?

Thanks

Viay

 

[s.cummings]

That is right small welds about a cm long and stagger them so while one part is cooling you are welding some where else. Then you should have very minimal warpage

 

[vijay]

Cheers, that's what I thought and said to him, guess there's no telling some experts I assume nothing can be done to straighten up warped metal?

 

[s.cummings]

No once she warps she is done I assume it is like ocean waves eh. If possable use a plasma cutter and cut out the warped pannel then weld in a new one using the proper technique.

 

[rtbcomp]

A panel beater could sort it, but I doubt whether you'd find one these days willing to work on anything less than a Rolls Royce.

Basically you bash the metal between a hammer and a dolly, pushing the lumpy bits into the hollows until it's all flat.

 

[fingers99]

as above. It may be recoverable with a hammer and dolly, but that will depend on you being able to access both sides. Pics?

 

[vijay]

Can access both sides easily but even when it's straightened out, it kind of flops back. I'll try and get some pics over the weekend.

 

[ozzman]

you need to get a peice of 2-3mm stainless and cut it to the size of a grinding disc. attach it to your grinder then skim over the panel it will heat all of the high spot up.

then while the panel is still hot quench it with a wet tool and the high spots shrink.

if u use a hammer and dollar on an already warped panel you will make it worse. as your streching the material further.

its is possible to hammer of the dolly o get the sheet smoothish but it will have a bow in it. then if you've got an oxy aceteleyne kit you can heat all the panel and shrink with a wet cloth.

have a look on u tube theres some good vids on there on how to do it.

 

[vijay]

thanks, that looks quite interesting, just watched a video on Youtube as you suggested

Is there an easier way of heating up the metal, would a plumbers torch work?

Vijay

 

[Drains]

As ozzman says, heat and shrink. You're looking for cutting torch heat. Heat the centre of the panel that's warped, or the centre of the warped area, than spray with water.

To be more precise, heat the area of excess metal, then shrink it.

Try the plumbers torch. It might work on thin stuff, but probably not.

 

[vijay]

I'll have to give the plumbers torch a go cos I don't have access to a cutting torch

If that doesn't work, I'll give the metal on a grinding disc

Vijay

 

[rtbcomp]

This links may be interesting

http://www.diracdelta.co.uk/science/source/h/a/hammer/source.html

http://www.concepttools.co.uk/Products/CatalogueItems.aspx?rangeID=22&Category=397

Look down the pages for shrinking hammer.

 

[vijay]

Can't get my head around beating a piece of metal would shrink it, how does that work?

 

[fingers99]

Whether it does or not is a moot point even amongst pro panel bashers!

Shrinking hammers have a sort of grid pattern which is supposed to gather the metal, so it becomes thicker (rather than thinner). Shrinking of any kind is maybe the trickiest of all panel beating tasks, and the harder the metal, the trickier it is and the longer it takes.

Some of the tools involved in the FROST catalogue.

You might be better off cutting out and re-welding.

 

[rtbcomp]

Can't get my head around beating a piece of metal would shrink it, how does that work?

I can't explain it - as Fingers said it's a strange concept. Perhaps a bit like working pastry so it becomes a bit thicker in places, thus gathering up the material.

A panel beater told me "the metals all there, just in the wrong places and you have to push it back again."

 

[vijay]

Ah, that kinda makes sense

Cutting it out is kinda last resort as it has some cut outs that I had made especially in them

 

[GeorgeB]

That is right small welds about a cm long and stagger them so while one part is cooling you are welding some where else. Then you should have very minimal warpage

Your weld would therefore be a series of 1cm lengths, to some extent joined up. Leaving aside the issue of warping, is this piecemeal welding much less strong than welding a joint all in one go?

 

[fingers99]

Your weld would therefore be a series of 1cm lengths, to some extent joined up. Leaving aside the issue of warping, is this piecemeal welding much less strong than welding a joint all in one go?

Done properly, it's just as strong. When you've finished the weld runs all become one, anyway.

 

[vijay]

Guys what can I say but a huge thanks for your help. It just about worked with a plumbers torch (with propane gas). Here's a pic of it back in place. A quick skim of filler and all should be good

Have a good weekend everyone.

Vijay

 

[peterd51]

Hi,

erm, that looks pretty horrible...

Is it just welded across the bottom with a couple of tacks at the top?

Is it supposed to look like that or is the job only half done?

You did say a 'professional' welder did it? :-)

Regards
Peter