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Q. I hope you can help me with a hood fitment issue on my '55 Chevy pickup. Your insight into pie-cutting the hood 11/2 inches was invaluable, and I'm very pleased with the results.
The hood to cowl gap tapers from 1/8 inch to 0, and there is no forward adjustment, as the front of the hood and fenders are aligned. To achieve a 3/16-inch bare metal gap, my thought is to scribe the hood-to-cowl gap, remove the rear hood cross support, and hammer a new edge to correct the gap. What I don't know how to do is hammer and dolly a new folded edge over an existing 90-degree folded edge.
Any of your valuable time will be very much appreciated.
Via the Internet
This month's article is about correcting the hood-to-cowl gap after pie-cutting the hood o
A. You're on the right track for getting the rear hood gap established properly. With a scribed line on the hood sheetmetal, you can use a hammer and dolly to make a new flange on your scribed line.
Honestly, this is a job that requires a high level of hand skill to do well. Unless you are highly proficient already, you would probably benefit from doing some trial runs on a scrap piece of metal. It's not hard to position the hammer correctly, but since the dolly is hidden under the metal you're hammering, it's hard to know exactly where the dolly is touching the metal, and that will determine where the new flange is being formed.
The size, shape, and weight of the dolly are important, too. Of course you need a dolly with a flat edge, a slightly curved top, and a pretty sharp edge between them. Most dolly manufacturers make a dolly of this style. In the Martin line, the "toe" dolly has exactly this shape. A dolly needs to weigh at least 3 pounds to be truly effective-so don't bother trying to use a "thin" toe dolly.
Nobody can position the dolly exactly on the first try, so you will be making small corrections to the dolly position based on the results you got from the previous hammer blow. With a little practice, you should be able to start on one side of the hood, and work slowly and consistently toward the other side, positioning the new flange properly as you go, right on your scribed line. After the flange is formed, you can make small corrections with the hammer and dolly. If you drive the flange toward the front of the hood, holding the dolly so it touches the top of the hood skin, but has a slight gap against the flange, the flange will move (and get longer), increasing the gap against the cowl. If the gap against the cowl is too large, you can fix that by holding the dolly against the top of the hood skin, centered on the flange, and driving the flange up against the dolly. This makes the flange shorter, and closes the gap against the cowl.
You are correct that the old flange will present some difficulties, since you'll have to flatten much of it out with your hammering. The key thing to keep in mind here, is that you need to do enough hammering to flatten the base of the old flange, but once the metal has moved enough to touch the dolly completely, further hammering will stretch the flange, which can distort the curve of the hood right to left. Even if you get a little distortion here, it can be corrected, but ideally you'd like to do as little correction as necessary.
Your job will be eased if you trim off a lot of the excess metal on the rear edge of the hood before you start hammering the new flange. I'd leave a minimum of 1/16-inch extra metal, but where the current gap is 0, and you'll be making a 3/16-inch gap, you can safely cut 1/8-inch off the flange, which will make hammering the new flange easier. Once you have the new flange positioned to your liking, you can sand the height of the flange to make it uniform from side to side, and reattach the rear brace.
Let me know how well this works for you, or write again if you have any further questions.