Sheet metal warping...

[Brandy]

Hi guys, I have a problem on the header panel i'm fabbing up for the "Express". I cut the first 8 inches from my '67 Coronet hood for the header and I don't want the contour lines that flow in from the front outside corners so I hammer and dollied them flat. Bone head move. That stretched the metal and put a bow in the sheets edge. I need to unstretch those two areas while still keeping the flat surfaces I created.

Help please? Any creative suggestions appreciated. Thanks!

 

[5.7 hemi]

Unless you have a shrinker/stretcher your left with a few options.
1. Get the metal hot and cool it rapidly,
2. Cut some slices in the warped area and weld back together.

 

[Mocajava]

I agree with 5.7 and would recommend the cutting slits unless you are very experienced in using the heat/contract method....you could cause more damage then you already have. Cutting the slits will relieve the stress you have already caused. As you probably already know....Cut the slits, reposition the header panel, tack back together after you are satisfied with the spacing and look. Weld with SHORT, 1" beads, skipping all around and letting the welds cool in between passes. You can always dolly the welds lightly to impart stretch if you get too much contraction. PS....I really like what you are doing with that header panel.

 

[747mopar]

I wouldn't do 1" beads, you can get away with it next to a heavy contour but it will warp the panel on something like that. Tack it every 1" then skip every other one putting another tack in between. Keep skipping around not to build up heat in any one spot until you've fully welded it with nothing but tacks. Then grind it down and hold a light under the panel in dim light to find any missed spots. Good luck, warped metal is a real pain.

 

[Brandy]

Thanks guys, I sorta thought the slits would be it. Now, hot to cold is not something I have ever done so I don't think i'll take the chance of screwing up further, the only hood I have. Thanks for the idea though.

Yah, I was sitting on the 'ole HD bucket and thinking about all of the crap I'd have to do to flip the hood forwards and miss the grille etc...and had an idea. I think it will work out much better to have only the thin front edge of the hood next to the header to need to clear the edge. I'll give it a whirl tomorrow and take pics. Plus it is less weight to lift forwards too.

 

[1967coronet]

torch with a small braze tip, start in the area you wish to shrink , in the center of that area heat it cherry red and then slow circle while expanding out to the edges of your wanted shrink area. pull the heat and slap a wet cool rag on that area.
wala........... you have just shrunk you panel.

You will want to experiment on some scrap panel to get the feel of heat/time and how cold and time to apply the cold wet rag.
Its pretty easy to shrink body steel but do practice some 1st.
we fix oil can areas like this pretty often.
Not trying at all to step on any toes , everyone has their own ways of preforming panel repair,
But myself I would advise not to cut it in strips / slits ect and start welding, I afraid you will just end up with a brittle mess that can not be worked, your .030 weld wire and that hood are two complete different animals.

Get a piece of scrap body steel and dolly and beat a nice old dent , oil can area and play with hot and cold.

 

[snakeoil24]

Cutting slits will not work, you have to shrink the steel with a tourch just like 67 said. If you can not do it ask someone for help who can. The slit cutting will harden that steel and make it worthless.

 

[Pistol Pete]

I'd go with a shrinking disc first myself. Here is a demo:
[video=youtube;X8cruauERmI]https://www.youtube.com/watch?v=X8cruauERmI[/video]

 

[Brandy]

Hmmm.....will have to buy one and try it out. There are several places I could use that. Thanks guys!

 

[Cmmopar]

I'd go with a shrinking disc first myself. Here is a demo:
[video=youtube;X8cruauERmI]https://www.youtube.com/watch?v=X8cruauERmI[/video]

Thanks for posting, going to order a set of discs. Found this interesting video on wolfs website:

http://youtu.be/rt07pLebQwQ

 

[Brandy]

Thanks Cmmopar, I got a lot from that video. I'll watch it a few more times. It's amazing how much change can be made through this method. I think many body shops would have cut that out and used an English wheel to shape a new piece and weld it on. That finished area looks nearly perfect.


Update..

I now have the two half's of the front header welded back together after priming the inside surfaces. It is bolted in place for mockup. Did some shrinking and I think I can make it work better after I fabricate the back edge that goes down and bolts to the radiator frame top rail. That drivers side fender still needs a bunch of work too. Thoughts?