 Though the shears were pretty...  Though the shears were pretty good at following the contours of the shapes we traced, we left some room around the edges. It seemed to be better to have extra material to trim away in the final fitting process than not to have enough. Plus, our cardboard templates weren't made to exacting tolerances. |  We used our bench grinder...  We used our bench grinder to trim away the excess material. It takes a little time shaping and adjusting until the pieces fit well. |  Prior to welding, we cleaned...  Prior to welding, we cleaned up the control arms and the reinforcing plates with a Scotch-Brite pad on an angle grinder. The best welds are made on clean metal. |
It can be tricky welding two pieces of metal together that are of differing thicknesses because the heat setting for the thicker piece can cause you to burn through the thinner piece. In experimenting with the heat settings on our welder, we decided that 100 amps worked best. We aimed the torch more at the control arm, since it was the thicker piece, and started a weld puddle. Then we slowly added the filler rod and moved along the seam. In places where the fit between the two pieces wasn't very tight, we had to bridge the gap with a couple of extra passes of filler rod. A hundred amps sounds like a lot of heat, but remember that you control the TIG welder with a foot pedal. Like the throttle on your car, it varies the power output. You'll often need more heat to start the weld. But once the puddle forms, you can usually back off the pedal and still continue to weld using only as much amperage as is needed. We're using ER70S-6 filler rod, a good general-use filler material for welding mild steel.>
OK, these welds aren't that great-looking, but we're still getting the hang of TIG welding. After the control arms cooled off, we sprayed them with a few coats of Eastwood's satin black wheel paint. It dries quickly and offers good protection against chipping.