Drilling the remaining F-705 bulkhead parts^3h

Today I continued drilling various parts of the F-705 bulkhead.

First, I made an arbor to mount a counter-sinking bit in a drill chuck. There were few a times when I wanted to counter-sink without the cage, so I thought this little adapter would come in handy. It's probably 1018 mild steel, which doesn't machine nicely if you don't make an effort (and I didn't -- as you can see by the surface finish 😁), which is what I have in my scrap steel supply box.

Then I moved on to drilling various other holes, drilling all four sides of the bulkhead plus doublers together, and drilling seat stop parts to the top channel.

I used my rivet fan to drill the holes in the seat stop angle (if I understand its purpose correctly). I made a couple of small mistakes here. First, I drilled #30 (well, #31, I now drill all new holes slightly smaller, then use a reamer) instead of #40. However, the fan is drilled with #40, so I had to use silver clecoes to attach it. Since the initial two holes were #30, the fan wasn't positioned as precisely as it could have been. Second, instead of drilling through the fan (which is what fan instructions tell you not to do, though), I marked the holes with the sharpie, then center-punched and drilled them. This allowed a couple of holes to migrate slightly. It's all good in the end but could have caused issues with a more critical part.

The angle needs to be spaced at 0.125" from the channel, and they give you the spacer for that: the center bar F-705B is exactly that thickness, so that's what I used.

The final result is not too exciting, but here it is.

The one part that is remaining for this bulkhead is an F-705K plate. It needs to be bent in the middle, and I don't have a bending brake to do so. So I keep thinking if I want to clamp it between two angles and "eyeball it" with the mallet or go to the Harbor Freight store and get their brake. Likely, the latter.