The tailgate was in reasonable shape when I got the truck except for the top rail that had a nasty crease in it, the two outer uprights had creases where the tailgate had been let fall across the rear bumper, but the worst part and the bit that concerned me most was the fact that the centre of the tailgate was stretched. This is also known as "Oil Canning" essentially it is where the middle section of a sheet of metal is stretched making it larger than it was. This then leads to it springing into a concave shape, you could press the centre and it would pop out, but as soon as you let go it would spring back again.
The tailgate as it was when I got the truck, you can't see the crease on the top rail as it is on the top inside edge.
Other than the crease and a few dents in the top rail it was pretty straight, so rather than try to work the dents and crease out and risk damaging the tailgate further, I decided to lead fill them. This was a fairly quick and effective repair.
I wanted to take the tailgate down to bare metal to see exactly what I had. So I decided that the best way to go about it was to use Paint stripper. Because of the complicated shapes and the pressed lettering it would have been a real pain trying to sand the paint off. After 3 coats of stripper it was down to the steel. I then steam cleaned it to get rid of any stripper residue and wiped the entire tailgate with thinners to help prevent it from rusting.
Oil Canning in the centre of my tailgate was the next thing to tackle, it would
spring into a concave shape, you could press the centre and it would pop out,
but as soon as you let go it would spring back again. I did a bit of reading on
the best way to try and resolve the problem and came to the conclusion that the
best way would be to heat shrink the metal i.e. Heat a small area in the centre
of the oil can and let the cooling metal then pull the stretch out.
I was cleaning up the tailgate getting ready to take on the task when Roger (Old Guy I rent the corner of my garage from) came by asking what I was doing. I explained what I was about to do and he winked at me and then proceeded to tell me how I SHOULD do it. He told me to find a lot of old newspaper and make myself some paper mache. Then make a doughnut out of it around the area I was heating, effectively making a heat shield for the rest of the tailgate. This ensures that all of the metal around the heated area remains cool and the heated metal has nowhere to expand other than in its thickness.
It was a very simple thing and fairly obvious, but I never thought of it.
After cooling the tailgate was as taught as it has ever been. There was just a small amount of plannishing required to dress the centre section and that was it.
The corners of the tailgate are not the nicest or neatest. There are gaps and the welds are not very neat. I decided that I would have a go at neatening things up by filling the corners and smoothing everything off. I used Lead as the filler as with all of the other body mods.
I had a bit of a re think over the Christmas holidays. I decided that I would try to make the tailgate a lot smoother than it was. The main area I wanted to change was the corner sections as the joints are really uneven. I had already filled the big gaps with lead to try and neaten things up as can be seen from the pictures above. But this still did not look as nice as I wanted.
I decided that if I welded in some new sheet metal at an angle on the two ends similar to the top and bottom it would look a lot nicer.
Here you can see the the corner pieces, they do say a Picture is worth a thousand words. The first pic shows the magnetic clamps holding the new sheet metal in place. They are very useful for holding bits like this that you just can't get a normal clamp onto.
At the same time as neatening the inner corners, I decided to fit some internal hidden latches. I had already cut off the tabs that the external latches and chains hooked onto. It was now time to weld up the ends of the top rail and then fit the new latches.
Here is the end result. It still needs a little tidying up but you get the idea. The latches are spring loaded outwards, so that they locate into holes in the bed sides. There is a slight problem in that the top rail was badly dented on one side. Unfortunately the dent is right where the latch goes. So I need to modify the small latch knob on that side to make it slightly longer, to allow for the extra thickness where I lead filled the area.
I have ground all of the welds down ready for the filler work. I just need to do all the boring bit now, spreading filler then rubbing it all down again, before a coat of high build.