My progress the last two days have been frustratingly slow. So there's not too much to report. After shuffling airplanes around in the hangar and getting the B-24 it's semi-permanent spot for the winter, I started back on fabricating structure for the tailgunner's section and didn't get far before I broke my shrinker.

So after a few choice words, I moved on to fabricating the tunnel gun position. The pictures below show how I went about starting this. I'm sure that there are just about as many different ways to do this as there are different sheet metal guys out there. I am by far, not a sheet metal expert. I learn something every time I do sheet metal work and with every piece of scrap I make. So, without anymore excuses, here is my description of today's work...
The first step for me was to take the old piece that I removed and place it on a new sheet of aluminum. I back drilled a couple of pilot holes and used clecos to hold the old sheet in place on the new sheet. I then traced the outline of the old sheet so that I could cut out the new piece.
Since we don't have a sheet metal shear large enough to cut this out the easy way, I had to resort to cutting it out by hand...sort of. I used a pnuematic shear to cut this piece out. This is .040 thickness, so cutting it with hand shears (which I prefer on thinner aluminum for accuracy) just would have been too time consuming. I'm sort of sloppy with this gadget, so I'll have to just even it out with a file later in the process.......
The next step for me was to transfer the holes from the original piece to the new piece. I just used those previous pilot holes to realign the two pieces together and started drilling. The reason I use the original piece is because I know for a fact that it fits the airplane. After all, I just took it off. The new piece's holes should be virtually perfect when putting it in place. I only transferred the outboard holes, however, as I will be cutting the hole out of the center of the new piece (tomorrow morning) to duplicate the tunnel gun port.
And after making lots of little metal shavings, the new piece has all of the rivet holes (that I will be using) duplicated.
I hope to have another update for y'all tomorrow. You
real sheet metal guys out there please take it easy on me. I know there are better ways to do this, but I'm just trying to shed a little light on how a dummy like me gets things done to "inquiring minds that want to know."
Gary