Sunday, January 4, 2015

Day 106 - Cowl 2.0 demolding

Today, I spent most of the day's daleking demolding and working on the cowl.  I took special care not to damage this second cowl attempt, unlike the first one.  I added a number of slender wooden stir sticks all around the mold to separate everything evenly, instead of slamming wedge after wedge of thick plastic spreaders and risk warping and cracking the part.

Despite the fact that multiple pulls are supposed to get easier, I managed to literally "break the mold" this time!  I don't think the mold is beyond salvaging; however, it would be wise to just make a brand new mold from a nice, cleaned-up fiberglass cowl.  That is if I ever feel the need to explore this damnable part of Rainier ever, EVER again!  This is the last bit of fiberglassing I needed to do, and for the foreseeable future, I am done working with that itchy stuff!  I'll still be using resin for a couple things, but no more glass fabric!  (Maybe.)

The cowl took quite a while to separate from the mold, but eventually, it did come loose.  The name tag inset made with the cut-up PAX badge came off with it, but it was easy enough to remove, carefully, with a razor blade.  I trimmed most of the fiberglass "fur" off of it with scissors.

I spent the next couple of hours using 80-grit sandpaper to even out all the ripples, bumps, and uneven surfaces.  I haven't yet done this step with the dome; it still has all its unevenness and such.  But the work on the cowl gave me confidence when I get round to sanding the dome.  Much of the gel-coat came off, which is why it looks so patchy in its current state, but once sanded smoother and primed, it should look great.

I was especially proud with how even the multiple layers of fiberglass and resin turned out to be.  I intentionally made the parts that were meant to be cut out much thinner than the rest of the cowl, so that my Dremel tool would pass through all that nicely and easily.  The rest was quite thick and sturdy.  There now appears to be a uniform thickness to the interior walls of the cowl where the eyestalk will eventually protrude.

I was completely covered in fiberglass and gel-coat dust by this point, so I also spent some time sanding the underside edges of the cowl so that it would lay as flat as possible on the dome.  Once done, I carefully aligned the position of the cowl on the dome and used my calipers to make sure the top was centered and that the right and left sides were evenly spaced from the front dome insets.  I used the calipers once more to determine a nice, secure, symmetrical place in which to place the four bolt holes so that the wouldn't be too near the edges (to prevent accidental cracking).

I used a 1/4" forstner bit in my hand drill to make the holes in the cowl first.  Then, holding it in place on the dome, made the first hole I've drilled into the cowl.  I was a nervous wreck (never having marred the dome before now), yet I managed to drill a corresponding hole into the dome.  I pushed one of my 1/4-28 steel button head screws through both the cowl and the dome, and made a pivot by which I could align the other three in place.  Before long, all four bolts were in place.

There were a couple of air bubbles on the cowl that revealed themselves during the sanding process, so I just need to do a bit of Bondo work to clean up the rest of it, and also to smooth out the front a bit more.  Then it will be ready for its eventual paint job.

(I also made plunger number 7.)

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