Cowl extension cleanup

So the last two nights’ work has been doing lots and lots of sanding on that extension piece I grafted not the cowl. The basic idea here was to sand a scarf, lay up multiple layers of cloth, and then sand the overlapping area back down flush. This was, to put it lightly, quite a bit of sanding. Especially since resin and cloth makes for some pretty hard stuff that doesn’t exactly sand easily.

It also makes it more fun that this is a contoured surface, though at least it’s not a compound curve. Still, that means my normal tools for trying to sand a straight line, like a nice sanding block, are no good here. I ended up wrapping sandpaper around a deep socket – yes, you’re reading that correctly – to make a sort of round sanding block. Then I went to town with that thing, for…a lot of time. I think it was about 45 minutes in that I really wanted to go tell Past Philip that that old gap really wasn’t that bad after all…too late now, though.

Tonight, I finally got things sanded down to a relatively flush point, so I switched to a soft foam block and 60-grit paper to finish the blend between the old and new glass. The result of all that work was this:

Next up was getting started on re-trimming that extension. I basically repeated the initial trim steps – laying the cowl in place, marking a conservative initial cut line, then gradually sanding the edge to fine-tune the fit. After a couple iterations, I was able to pin the two cowl halves together again. The gap still needs some work, but I think I’m going to go with the approach of riveting all the hinge halves in place before I remove any more material:

Oh, and I’m still not done sanding here, even ignoring the gap itself. I took a wild guess that eight layers of cloth would be about the same thickness as the rest of the cowl, but that looks to have been too many layers. The new grafted edge is a decent bit thicker than the rest of the cowl, to the extent that I can’t pin the upper cowl to the firewall right now – too much misalignment. So I’m going to have to work on thinning that extension down some before I can put this whole task to bed.

In retrospect, it probably would have been smart to do some test layups to get an idea of the finished thickness of different layer counts. But, much like the whole “that gap wasn’t so bad after all,” that ship has sailed, and there’s not much to do except…more sanding…

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