Well, it looks like the theme of doing fiberglass stuff repeatedly is sticking around. Last week, the day after adding the glass, I took a deep breath and tried popping the tips off. I was happy when both came off with no drama at all. Next, I got to work on one tip, blending the nee glass into the old tip to complete the scarf joint, then trimming the overhang to fit.
It was about this time I discovered an issue: the glass around the front of the counterweight sat very proud of the adjacent counterweight skin. I’d thought that my glass would have a nice little lip that I could sand flush to the skin, but nope, wasn’t going to work that way. Basically, there were a few different problems that came together here. First, the tiny bit the counterweight was inset compared to the skin wasn’t enough to accommodate the glass wrap. Second, three plies of glass was probably way more than I needed. Third, I think my layups were way wetter than they needed to be, exacerbating the excess thickness of the glass.
The fix for this was pretty obvious: I needed the counterweight set back further from the skin. That meant spending some more time sculpting the front of the counterweights, to provide more room for the glass wrap, plus cutting the glass off and redoing that entire area.
So today I did the cutting on the tips, along with the drudgery of sanding a taper into the edge yet again to allow for the scarf joint. Then I got to the fun part of the program, working on the those counterweights. This time I tried a different technique for the shaping; last time I did all the work with files, but found that to be pretty tedious. This time, I decided to try using a sharp (but not valued) knife to shave bits of lead off, and it worked pretty well for rough shaping. The knife also gave me a decent way to shape the lead near the skin without damaging the skin – much easier than when using a file. After roughing with the knife, I did still use files to finish and smooth things out, and especially to round the corners off.
In the end this amounted to carefully shaving about 1/16” off the front of the counterweight. This should provide me enough room to get a thin glass wrap around the front; when I do the next layup, I’m only going to add two layers instead of three, and make sure to do better at squeezing out excess epoxy. Another thing I’m going to do differently is to trim the glass at the counterweight-skin junction (after giving it some time to partially cure); this way I can tuck the edge of the glass into the inside corner between the weight and skin, which should help prevent it ending up proud when it cures.
My intent tonight was to finish re-taping the counterweights to be ready for laying up tomorrow, but…I ran out of packing tape. Guess I’ll run out tomorrow and pick up some more, I’d like to get working on this layup pretty quickly after work tomorrow.
In other news today, I decided to pick up on the rudder bottom cap again too. Come to think of it, I think that was the part that got me started on doing fiberglass in the first place. For that, I just mixed up some of the System Three epoxy I bought, and added a skim coat over the area of the taillight that I reshaped previously. That should take care of any pinholes from the micro, and get me in pretty good shape to go ahead and cut the hole for the taillight and get the bracket epoxied in place inside. Then hopefully I’ll just need a few coats of primer to get rid of any remaining imperfections, and that piece will be ready to install.