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  #1  
Old 03-10-2012, 02:21 PM
Strum Strum is offline
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Default 1934 Chevy Rear Panel

This rear panel has been a disaster. Some one cut holes in it to put in tail lights that didn't belong. I had to weld some sections on the flange at the bottom edge that were rusted off. After all of that, I had to use way too much filler to save it. It's a long story, but I would like to cut it out where the tape is, and replace that section with a new piece.

So, how should I make this? As you can see, it curves both directions. There is a flange at the bottom that nails to a piece of wood and it is folded over a 1/8" steel reinforcement bar at the top.

I really don't know where to start. Davids DVD showed making a low crown panel by hammering all over it. Or would I use a buck? Or shrink the edges? I have no idea.

P1010349.jpg

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Old 03-10-2012, 02:38 PM
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Kerry Pinkerton Kerry Pinkerton is offline
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Eric, what do you have to work with and what is your skill level? Us telling you to do this or do that won't make any sense if you don't have to tools we're talking about.

Putting the low crown in the panel is pretty easy with an Ewheel. Some folks can do low crown work with a planishing hammer. I can't. It can be done by hand with lots of patience.

The lips and flanges will be the hard part. You'll probably want a Lancaster style shrinker/stretcher for those although they too can be done by hand it's not trivial.
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Old 03-10-2012, 04:14 PM
Strum Strum is offline
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I am working with hand tools only. I have access to a slip roller, if that would be of any help. If a wooden buck would need to be created, that would not be a problem. If it helps any, I have a lot of experience doing metal shaping the wrong way
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Old 03-10-2012, 05:52 PM
ShawnMarsh ShawnMarsh is offline
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I would stay away from the slip roll, it's not much use on this project. Also, a wooden buck would be overkill for a panel like this. You will have to stretch like David shows, and be patient. Like Kerry said, this type of panel is quite easy and quick with an English Wheel, but if you don't have access to one you will have to work it slowly with the hammer and steel table.
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Old 03-10-2012, 06:16 PM
Strum Strum is offline
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If I use the hammer and metal table method, is the idea to space my blows closely together towards the center and further apart as I get towards the edges?

After I achieve the crown I need, what method should I use to form the flange at the bottom and roll at the top?
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Old 03-10-2012, 07:13 PM
Einar_S Einar_S is offline
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If I remember right David shows how to make the flange on his DVD hammering it up against a piece of steel. I think he used a dolly as well as a piece of rail. I have a heavy chunk of steel with the edge slightly rounded for this.
I understand the upper edge is bent over a round steel bar? Then you can hammer it over the bar in situ if you support the bar against the hammer blows using a heavy chunk of steel.

And you are right on the spacing of hammer blows. You should also buy/make a slapper to spread/shrink down any puckers you might create.
And if it does not go as expected, don't fight the impossible. Sit back and figure out why, then cut a fresh sheet and try again.
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Old 03-10-2012, 08:39 PM
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Draw a grid on the panel so you can space your hammer blows evenly along the panel. It won't take as much stretch as you probably think to produce that shape. May light hammer blows are better than a few heavy hits. You will learn a lot about how the metal moves with this project.

A lancaster style shrinker stretcher would be a big plus for this project. Neal Dunder, Gitzit, has the best bang for the buck with his stippled set.
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Old 03-10-2012, 09:20 PM
Barry Barry is offline
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On the hammering, follow what Joe said about the grid pattern. Go for a hammer that gives you about a 1/4" - 3/8" contact area. Smaller will leave marks, bigger (ie flatter hammer face) will need too much effort to move the metal.
Work methodically, using the grid to guide you. Aim for a comfortable working position that allows you to work in a repeatable, constant, sligthly overlapping pattern. You don't need much force at all - allow the hammer to do teh work. With good posture and hammer technique you can keep this type of hitting up for hours - Although I'd be surprised if you even need 1 hour to develop that amount of crown.

Work the entire area (leaving about an inch all the way around unworked) first and then decrease the work area to develop more shape in the areas that need it.

Not sure what you're describing on the flanges but either a simple tipping (and then hammering on it's edge to shrink it) or working it around a bar of the correct radius should get you there.
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Old 03-10-2012, 10:22 PM
Strum Strum is offline
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How do I control the shape with the hammer method? Lets say I need more stretch along the vertical axis. Would I concentrate my blows more tightly along the horrizontal axis to cause it to crown along the vertical?

Once I get the crown right, will tipping the flanges likley change the crown? The bottom is just a 90 degree by 1/2 flange. The top curls over top of a 1/8 thick piece of steel wiith about a 1/2 inch overlap.

I have a 9" shrinking disc. Would it be useful in any way?
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Last edited by Strum; 03-10-2012 at 10:37 PM.
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Old 03-11-2012, 05:51 AM
kfs kfs is offline
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you work the center more than the edge

picture are of a boot lid, but method are the same



picture are taken at Norway Winter meet, two newbeginners making a skin for a 32 cupe boot lid 1,25mm alu
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