I was WAY nervous, especially about wasting a gas tank. I bought a rusted up piece of crap for $10 from a guy, and practiced on that. The best way I can tell you how to do it, is simply sit on the bike in your normal riding position and take a sharpy and outline you legs for the pattern.
A lot of guys say that using a dead blow hammer will make the "indention" go outside the lines a bit, caused from cave in, but this wasn't the case for me what so ever.
-I outlined the tank.
-Sat it on a stool, for height purposes, and it also had a good soft cushion to help absorb the impact. With the gas tank on its side, doing one side at a time
-But here is the key.. I never hit the tank harder than I would a good firm knock on a door.. Kind of like you know someone is in the back room watching a football game at a reasonable volume, and you are trying to get there attention. Just a good firm, solid wack.
-Start in the middle, and work in circles. Counter-clockwise/Clockwise, it does not matter.
-Work you way from the center to around the edges of you marks/template.
-Once you get to the edges, angle the hammer slighty, to conform to the contours/depthness you're trying to achieve and do this all the way around the edges.
Surprising I don't have a lot of divets from what I have seen from other posts and other forum pictures that require a lot of bondo. I believe this was due to the consistency of impacts, and using the same amount of force all the way around.. You may think it is not getting anywhere, but after a while you will slowly see the results. I would rather achieve slow suddle movements, than drastic, OH MY GOD, indentions..
Also my deadblow hammer was of light weight/ounces. And it consisted of a rubber mallet on one side and a plastic mallet on the other side. I always used the plastic side of the hammer. I believe it is a 12oz hammer. I'll post again this afternoon with hopefully better pictures and the exact oz of the hammer.
This process also only took me about 15 minutes.. Not to bad for a unique one off gas tank that brings some flare and curves to your design.
Also, the bottom edge where the weld is that meets up with the bottom of the tank. That's is where the only crucial part of the task is. You're only indenting the center, and creating a look and function. Hitting to much on the bottoms could result in flared edges, and quite possibly damaging your petcock, which I did on the practice run. I believe one of the pipes that stick up inside the gas tank fell off. So just try and pay close attention to the bottom edges.. Just take your time, stop ever so often and hold the side up to the light to survey the work. And dents are easier to make than they are to unmake.
I hope this helps. I am very happy with the results, and it beats having to pay hundreds of dollars for another gas tank with the same look. This way you are only out $15 bucks for a good deadblow hammer, and atleast you can say you did it!
JAG
