Can you "crown" sheetmetal without an English Wheel?

How would a guy put a crown in flat stock without an English Wheel or a shrinker/stretcher? Is it even possible?

I had some rust repair to do on the lower jambs of my '60 F100 door. The skin was really beat up so I decided to remove it about 1/2 way up. I fixed the rust in each lower corner and now I'm planning on skinning it myself. There's very little crown to the panel but I assume there has to be some to keep it from oilcanning.

How would you do it without any specialty tools?

Here's a pic to give you an idea of the scope of the job.

 

A way my brother did a skin like 15 years ago was cut a sheet of metal in half and welded it all the way around and welded a nipple in the corner and aired it up.

 

could ve done wirh a hammer and dollie./

 

yep

 

You can get a gentle crown by rolling the sheetmetal with an oxy/acet. bottle.
I've seen Model A hood tops curved with the bottle method.

 

Could be dangerous for the inexperienced. Any suggestions on where to start? A pattern to follow? There isn't much crown to it at all so maybe rolling it over a bottle might do the trick.

I'm still open to pointers.

 

For some curves you can make a wooden buck, heat the piece to soften it and use a shrinking hammer for the primary crown, then a leather bag full of shot under it to smooth down the ridges. Or you could hammer weld it by attaching the top and using a buck heat it down and tack it using the heat of your weld to chase the crown into shape. Not for amateurs though. The English wheel is better though because pretty much any other way is going to thicken the crown and thin the attaching edges to where they will be a bitch to weld without the crown sagging when you put the heat to it.

 

I'm late...i gotta run. Damn Hamb!


Jump up and down on it! Ha....

Media blasting, can put a crown in it that way too!

 

That's not a crown. It's a roll.

Just been looking at some John Kelly vids. He shows how you can do it with a shrinking disc. You shrink the edges rather than stretching the middle. Can't say I have ANY first hand experience in it though. Check the post currently on page one about the shrinking disc and check out John's links on there.

Pete

 

Hammer on dolly the center, to stretch it....not for the inexperienced, or "tuck" shrink the edges. Do a search to find out how..but not really a great technique for a beginner either.
Ya'know...there really ISN'T an "easy" way for a beginner to make a gentle crown.
It's not too easy for experienced, either, sometimes.......

 

There may be a slight crown front to back on that door. It has a simple roll up and down. You could use a good body hammer with a wide low crown on its face, and set your metal on a flat steel work surface. Hammer on the metal where it is in contact with the work surface to stretch.

This would take a long time, and be a bit tricky. If you roll the up and down curve first and then start stretching, you would have to re-roll the curve every time you wanted to check how much shape you have generated.

If you fail to get the up and down curve each time before checking how much front to back curve your stretching is making, you will not get an accurate idea of what is happening because the curve in one direction directly affects the curve perpendicular to it. You may think you have achieved the right amount of curve front to back only to find that once you roll the up and down curve again, the front to back curve has flattened out. This would mean you need to stretch more. Pretty tricky.

You might try a smaller piece first to get the idea of how much hammering is required and how to control the contours.

John www.ghiaspecialties.com

 

Go to the junk yard with a hammer and wide, sharp chizel and a pair of gloves and cut the roof panel out of something.

 

I'm with Kev on this, roof panel or big trunk lid.

 

A gas bottle can be a good tool, I made the lower grille chin on my 37 by gradually shaping it over the top of a gas bottle valve cap.

 

It looks looks like the panel is basically flat and rolls in towards the edges. I think the guys are right by using a oxygen bottle or something a little smaller to form the radius along the lower edge.

The middle part of the panel looks like it would have probably no more than a 36" Radius. If your going to try to put that light of a "crown" in the panel without a wheel its going to be pretty unpredictable and hard unless you have a Powerhammer? Just shrinking the edges will have little effect on the middle of a panel that large. But With a english wheel it should be pretty basic as long as you are careful......Make sure the lower die is 36" or larger radius. Keep the tension Super light because if its to tight the wheel will tend to put ridges in the panel where the wheels make contact. Then to smooth out those ridges you will wheel it more and put to much "crown" in the panel....Then your screwed because its super tricky to take "crown" out once it is there.

My tips would be to go super slow! And sit down on a stool or chair so the wheels are eye level and you can see where the dies are contacting the metal. This will help you make sure you are making even & level passes through the wheel. It will also help you know when the "crown" is right and when to stop......

 

Some Italian Coachbuilders used to create low crown panels without fancy equipment.

If you draw a grid on the inside of the panel,lets say 2" squares.
Then with a low crown body hammer and anvil,you hit once at the
intersection of the grid lines.Then see how much shape you have.
Need more shape,? Hit those spots again.Eventually the shape will
start to develop,then you can hit in between the intersections.

By spacing the grid lines differently,you can create different shapes.

Learned that trick from Ron Fournier.He discovered evidence of this
method while doing some restoration work on a high end Italian car.

 

Find a nicer door, or pull a skin off one.

 

Hey,

' given that you have few , if any metalshaping tools, I'd go with Unk Ians
suggestion.....or: First take a straightedge and hold it up to the other un-
damaged door skin. At this point I'd take some templets off that door in
thin cardboard, say donut box cardboard. Use these templets to guide your shaping. All the wheeling, beating & or powerhammering will be as usless as
mule cum, if when done the panel isn't the correct shape! I'd next blank out the repair skin from flat sheet say 18-19 gage cold rolled steel, turn a
ninty degree flange on the three edges that fold over the door shell, leav-
ing a 1.1.5 flange of material on these flanges. The 'Lancaster-type' shrink
ers will pull a nice controlled crown into a panel like this. The fuckin Chi-Comms sell repoped copies of these for less than a "C'' note! but I'd pop for a real 'genuine article' for my money. When you get one of these, pratice pulling radius shapes in sheet, to see what's possible with this tool.
If you start your shrinking in the middle of the flange on each side of the
panel, you'll see how fast controlable shape can be produced.
Yeah, you could beat a crown into this panel, by clamping a universal dolly into a vise, and with overlapping hits form the crown you're after,
but why?

Swankey devils C.C.
"Meanwhile, back aboard The Tainted Pork"

 

+1

save some dough on high buck equipment......

 

I was gonna say the same thing. I saw that method being taught years ago. I have tried it in small areas in a pinch and it worked well..

I think you can just hammer the edge with a hammer and dolly to get some crown for a patch panel.

Also keep in mind on that panel you cut off if will tend to want to sink in. You need to push it back up where it belongs before you weld on the new piece.

 

Wow, This place rocks. Where else can a regular guy put up a question, and have it answered by a master like Jesse james. I love the HAMB!

 

I really appreciate all of the advice given here. I will consider each (though I never thought of finding a better door! ).

I do have your basic body hammers and dollies (even a new-fangled shrinking disk), so I just may begin with the grid idea and see where that leads me. I've been messing with beating out panels for awhile, trying different techniques and reading as much as I can find but nothing is a substitute for experience. Thanks for sharing yours with me. I'll keep you updated and let you know how it turns out.

 

Hey Todd, get a hold of Frank. He's five minutes from your place and if his toe is better would most likely be more than happy to help you out. He's got lots of metal working tools. He made some crazy 1/8 scale 32 fenders a little while ago. He'd be the guy to talk to.

 

Hey, who you calling a regular guy?

Actually, if you consider this entire thread, there's an impressive list of names here. A lot of talent, including you Mr. Sibley.

 

His toe is better. I saw him at Midland today. Didn't talk to him though; he was pretty busy. He's tough to keep up with when he's not napping.

 

you are not wanting to just put a crown in metal you need the exact same crown as the door had before you cut it up.

 

Thats funny shit. LMAO

 

Really good stuff. I was hoping you might speak up. Your bike tanks kill, those shapes are at the edge of metallurgical and human possibility. And, no I'm not kissing your ass, you are an artist with metal, and I respect your stance on building things to be safe to drive and ride.

 

One tool that really works good is a stump. I stump with a small hollow will do a crown. You don't need much. I would suggest no matter what method you use lay it out on the panel. Draw a grid pattern on the peice so you can stay consistant. You can use a few small test peice to cut down on the scrap.

I have a wood stump, but I also use this tank end...


What gage steel are you working? Do you plan on welding across the middle of the door? That could be tricky. Your next thread may be hammerwelding?

Jeff

 

go with 14 gauge metal so it doesn't 'oil can' weld it in flat and bondo that baby and sand till the cows come home. ha.. j/k dont follow my advice. I was just reading and thought someone needed to give you the lazy mickey mouse way If you can't find a good skin, ask around for a friend with a wheel.
Anthony