So, I have been referred to by friends as having A.D.D. For those not familiar with this condition it is a disorder that.....ohh look at that, it's snowing! Wait, what was I talking about....oh yeah. Anyway, I tend to have quite a few projects going on at once. Usually, I am working on three or four projects at the same time and jump back and forth between them when I get bored.
One of the projects currently is a gas tank for a '40 ford truck that I am working on. This truck started from a cab that I traded for a set of headers I built about a year ago. I'll cover more on both of these in the future, I promise. For the tank, I wanted it as large as I could make to fill in behind the passenger side of the cab in front of the rear end. I took some measurements and made a quick and simple solidworks drawing.
I transferred the measurement to a piece of 3/4" particle board and cut two piece to use as forms for the sides. I didn't want the lip on the sides to have a sharp bend, plus it would be difficult to manage the corners, so I opted to take a router and radius one side of the forms.
Once I had the forms ready, I cut the sides out of 18ga. I used 18ga primarily because that is the stock I had in inventory. 20ga is much easier to work with but 18ga will hold the shape much better. I do not work with anything less than 20ga just because I find it difficult to weld. I added about 5/8" extra material around all edges from the forms I cut.
In order to prevent the side from deforming as I hammer the lip, I sandwich the side between the two forms. I started to hammer the at the corners. This is because in order to get a nice clean radius corner, the material has to be stretched. I do not want to simple beat the corner down but I want to pull and stretch it over the form. This pulling is done with your hammer strokes. I do not hit with the hammer straight up and down but with glazing blows in the direction that I want the material to go. Once the corner has begun to take shape a move onto to the straight sections. You want to work the edges down with several passes. Each time you hit the metal, it is stretching it. Stretching is what we want in the corners, not on the straights. Here are some pics of what i am talking about....
