Outdoor Panel & English Wheel Question - Professor Hammer's Metalworking Tips

Written by on January 19, 2010
Outdoor Panel & English Wheel Question - Professor Hammer's Metalworking Tips View All 1 Photos

Q. I have a question on door panels and forming them with an English wheel. I bought two doorskins from an aftermarket supplier (they're reproduction), and they are lacking the proper shape (which is contoured a bit like a pumpkin seed). I am starting to wheel them, using a 12-inch radius, 4-inch diameter wheel, 2 inches wide. I'm cautious, so I'm approaching this slowly, but I'm being told I could do the same thing with a bench or post dolly.

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I figure I will use a little hammering, but mostly the wheel for this project. I can't seem to picture a 34x28-inch panel being held and hammered by one person. It seems like a huge challenge to get this shape on a post dolly, with a free hand to lightly tap the shape into it. Can it be done? It seems whoever makes the reproduction panels uses deep-draw metal. Paul Zuhosky Via the Internet

A. Yes, door panels, or virtually any other panel can be made with several different types of handtools, including a hammer and post dolly. While this is possible, if you have an English wheel, that is a much easier way to produce a low-crown compound curve over a large area, and it will almost certainly have a smoother finish than a hand-hammered panel.

The primary principle that enables an English wheel to dome metal is stretching the metal. If the gap between the wheels is smaller than the metal thickness, the metal contacted by the wheels gets compressed somewhat, which causes the metal to dome. You can accomplish the same thing by hammering on-dolly. This can be done with a handheld hammer and dolly, with a hammer and post dolly, with a planishing hammer, or with a variety of other tools.

Doming a small piece of metal by hammering on-dolly is fairly easy, but the larger the panel, the more difficult it is to keep the doming consistent, and it's more difficult to correct any deviations, too. A 2x3-foot panel will be quite a challenge to shape uniformly, but it can be done, and has been done many, many times.

Someone told me of an alternative to using a post dolly for hand-shaping large panels. The trick is to draw a grid of lines on the backside of the panel, with the lines spaced about 1-inch apart. The panel is laid face down on a clean, smooth, heavy steel plate, and then you start hammering on the backside, with one hammer blow at each line intersection. Once you have covered the whole surface, check the contour. If it needs more doming (and a doorskin probably will), start another round of hammering, but this time aim each hammer blow at the center of the squares you've laid out on the back of the panel. Again, cover the whole panel, hammering once in the center of each square, and when you're done, check the contour. It will likely take several rounds of hammering, alternating between the line intersections and the centers of the squares, but if you work slowly and carefully, you can develop the shape you need, while maintaining good control. Any small areas that don't have enough contour can be raised by hammering a bit more in those areas, but be very careful to bring up the whole panel evenly, since it's extremely difficult to bring down any area that gets over-stretched.

While you can do pretty much the same thing by working with a hammer and post dolly, I much prefer working against a large flat plate, and for large panels, it's easier to balance the panel, and to orient it so there is no air gap under the section you're hammering on. Obviously, the grid drawn on the panel is simply a guide so that your hammering pattern will be uniform. While in theory you don't need to draw a grid, I've found it really helps me keep the doming more uniform than when I hammer without a grid.

Many, but not all, patch panels are made from drawing-quality steel. All of the techniques I've listed will work on both drawing quality steel, and "regular" cold-rolled steel.



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