Monday, December 20, 2010

Wrapping gifts....

Around this time of the year, it is so difficult to find time in between all of the holiday and family stuff.  Sorry I haven't posted anything.

Anyway, the next step for the gas tank is to make the perimeter.  I do not like to simiply make each individual side and then weld them all together.  The problem that arises is that you end up with a lot of weld in an area of the sheet metal that is not stiffened by an edge or lip.  This can lead to warpage and leakage.  Also, this type of joint is not very strong and vibration resistant either.  So my solution is to use one piece and wrap it around the sides. 

Since this particular tank has rounded corners, I have to make the wrap follow.  I started by cutting a piece of sheet metal the width I wanted for the tank and as long as the piece that I had.  Unfortunately, I did not have a piece long enough to wrap complete around, so I will have to do it in two pieces.  I picked a point on the tank that I felt comfortable to have a weld and this will be my starting point for my measuring.  I did not want to see any weld of joint when the tank was installed, so I decided to make the starting point on the front where it would be hidden by the cab.  On the side pieces, I measured back to the first corner where the corner started and then wrapped the tape measure around the corner to where that same radius ended.  I transferred those measurements to my wrap.

I then had to figure out how I was going to bend the corner.  I thought about using a break and stepping though the corner but that would yield a bunch of unsightly break lines.  I couldn't live with that, so, I can up with this....

I "built" what you could call a temporary corner break...I guess.  What ever you want to call it, I worked great.  I started with a piece of tubing that I found that was slightly smaller radius than the corner.  I screwed two pieces of wood to table about an 1/8" wider than the part I was bending.  This is to help line the part up to keep the bend perpendicular to the edge.  I then used some more wood to clamp the tubing down.  Once everything was in place and clamped down tightly, I bent the piece around the tube slowly just using hand power.  You can help persuade the part with a hammer but take care not to put hammer marks in the part.  I usually use a piece of wood in between the hammer and the part to help transfer the force over a wider area than that of the hammer face. 

I continued with the measuring and bending until I ran out of metal.  Since I had to do this in two pieces and I did not want to have to contend with a bunch of warpage, I bent a 1/2" lip on the start and end of the tank wrap.

On a side note, a project like this make you realize that you will NEVER have enough clamps.