Metal magicians....

[BigIrish]

...help me out with this one. At the point where I joined the sheetmetal together on the top of the cowl, I have a slight ridge. I guess the metal warped a little.

How to shrink the metal and knock this down? I could slather on a bunch of bondo and cover it but rather not do that. Its 20ga steel.

I would just leave it but its not perfectly centered so looks silly

 

[rustybeercan]

Irish,
Try a shrinking hammer. Eastwood probably has them.

Beercan

 

[Unkl Ian]

Hammer and Dolly to smooth it out.

The so called "shrinking hammers" are marketing BS.

 

[Blue Eyed Devil]

Hammer and Dolly to smooth it out.

The so called "shrinking hammers" are marketing BS.

Yes they are.

Some good old fashioned planishing will get the majority of it out, but it won't be perfect. Be careful because the MIG weld is very hard and prone to cracking. Try to work the weld more as you go. Go slower and keep an eye on what the metal is doing. Work it with a hammer and dolly a little at a time and the end result will be much better. Good luck!

 

[Rev Tex Devlle]

shrinking wheel you can buy them for 50 bucks, works real well i had personally watch the demo up close , it was amazing look up shrinking wheel on the web!

 

[DJ3100]

Shrinking discs work well. It will shrink a couple thousands .002 at a time, so it take patience. Check out this site http://metalshapers.org/101/index.shtml
(I think I screwed up this link click on Learning center.)

However, the ridge is very likely caused by the metal shrinking from the weld, which means you need to stretch it. Hammer on dolly as has already been said. If the weld does indeed crack, you can anneal the weld with a torch which will really screw up the shape. But hammer and dolly until it comes back.

 

[ratdog]

When I mig welded all my patch panels they all came up like that no matter how carefull and slow I welded, but hammer and dolly worked it all out flat no problem,never had any cracks, just go slow and steady,don't hammer too hard,just a lot of lighter taps evenly along the seam worked pretty well for me.

 

[Donuts1]

I used a torch and cold rag to shrink mine down, but it can get ugly in a hurry!

 

[screw]

I remember in trade school, they told us a thousand times how to stretch metal, by hitting metal on metal but on the exam, the question was, How do you shrink metal and the answer was "with a wooden Mallet" So I'll suggest trying to dolly it out with a mallet and a chunk of 2x4 underneath to strike against. Let us know how it goes if you try this. Good luck!

 

[jfg455]

I used a torch and cold rag to shrink mine down, but it can get ugly in a hurry!

this will just harden the metal and make it harder to work and more prone to cracking. work the lows by hammering off dolly (dolly under the low spot, hammer around the spot without hitting the metal on top of the dolly) and work slowly. you will get there. you can shink it by warming a spot and hitting the center with a pick slightly. then as it cools it will bring the edges in. just my $.02