Technical Sheet Metal Gurus Input Needed

I am in need of some sheet metal mastery or magic.
I have a louvered panel I am trying to install on a '31 Ford Model A sedan.
The rear body panel is convex both vertically and horizontally.
The panel is flat.
I do not have an English wheel.
The Question: where to make the relief cuts?
Help is appreciated!
thanks

 

Concave or convex, it would fit either sex, but oh what a bastard to clean. . . Part of an old Rugby song, never mind.

actually, I would make a cardboard/poster board template. The paper will tell you where it needs to be cut, just like the metal.

 

probably something like this...



and if you stare at that picture and think about it a while, you'll see that you want to shape the panel, before you punch the louvers.

 

Along with the above I would make it like a skin, folding the edges over on the sides and bottom.

 

You can do it by working the edges, no cuts needed

 

Louvers add strength and less flex to a panel. I'd hate to try to make a plain flat panel fit, and now with louvers in it I don't think it can be done unless you make drastic cuts like Squirrel shows. Just trying to shrink the panel outside the louvers will be futile.

Those original back panels can be unbolted from the body and brought right up to a louver press. Then you've got ZERO welding.

 

I agree with alchemy that is going to be a nightmare to make look good. Even without the louvers working the outside edge of a panel that size is never going to change the shape in the middle and your are going to end up with curved edges with a big flat spot in the middle.

 

I don’t have any suggestions, but is this functional or decorative/style/themed?

 

What if you shape the panel first, then louver it?

 

maybe not much help, but when my boss added these, the hood lost almost all its contour.
To fix that I painstakingly stretched each one by hammer and dolly work.
I set a round piece of pipe under the hood, I put pressure on the hood with straps. Then I used a homemade piece that fit between the louver and hammered. Then moved the pipe about 1/8 of an inch and repeat.
It eventually returned to its correct contour.

On a side note. There is no filler in this hood.

 

I hope it's functional because I don't care for the style at all. Not my car, though.

 

If you start hammering in the middle, between the rows, it should start raising that area.
That will start adding contour.
Possibly turn the panel over, hold a flat dolly on the outside of the panel and hit with a contoured hammer on the inside of the panel.
Just a thought.

 

either shrink the outer parts, or stretch the inner parts.

But starting with the correct shape piece, then louvering it, usually works out better.

 

^^^yep^^^
Even a flat piece with no louvers would do the same, only now the louvers add more stress or strength to the panel.
An English wheel is not needed to contour a panel, it just speeds the process. A bowling ball secured to a sturdy table along with proper hammering can shape it nicely. Or hammering over a contoured stump.
My planishing hammer is an acetylene bottle cap welded to a bench.

 

the yellow arrow area was contoured over the acetylene bottle cap.
The red arrow is where the two pieces that make the wheel house join. The joint area was contoured by hand tuck shrinking that was hand planished over the acetylene bottle cap.

 

The problem I see here is, if you make relief cuts vertically between the louvers, you're going to lose the spacing layout. The top row of louvers will be closer together than the center row once it's all tacked into place. Plus, the amount of welding and grinding you're going to have to do to tidy up the seams is likely going to warp the panels unless you take an incredible amount of time and effort to weld and grind, and then you're still likely to have to do a lot of bodywork in between the louvers, which will be difficult.

It can be done, but it would be less work to make a new panel, shape it, then louver it, or remove the current panel from the body, and louver that.

 

Agree with the others, not going to be easier than starting over.

Set it over a camp fire with some bricks on top...

 

Maybe you could shape or make a couple of dies for a bead roller that would act like an English Wheel and roll the areas between the louvers.

 

Wow. Thank you all for the valuable input. Now I am thinking of having the rear panel louvered and use the flat panel for something else. Thank you all for the feedback.

 

Oh, to answer one of the questions, the panel is decorative.

 

Here is what I was thinking, just with more louvers. I can cut the panel into manageable sections.

 

Louvering the original A bone panel is the way to go, but since your flat panel is at hand rodderings photo looks like a viable solution & the aircraft, &/or industrial look is isn't all bad provided the riveting thing isn't over done.