Team Seacats

After about 16 hours of coaxing, soaking, coaxing a little more, soaking, trying air pressure, trying water pressure, letting it soak overnight, coaxing a lot more, etc. I finally was able to release the mold from the plug but not before the plug was in pieces. I made several blunders that ultimately led to pretty substantial damage to the plug and a less-than-perfect mold. After finally reaching the point where damage to the plug was an acceptable alternative, I drove wooden wedges between the mold and the plug. Amazingly, the wooden wedges did very little damage to the gelcoat on either the plug or the mold but it did result in the plug coming apart leaving the center section of the plug still firmly planted in the mold. Another hour and three bleeding knuckles later, the center of the plug finally separated from the mold. In hindsight, contrary to my usual style, I went into the layup of the mold without enough preparation. I’m going to write this detail so I can look back to it for the next go ‘round.

I first mixed up 4 ounces of orange tooling gel coat (which was plenty when I went to coat the plug with blue) and it managed to only cover about ½ of the plug. A second round of 4 ounces covered the rest of it – but it could have stood to be substantially thicker. More like 12 to 16 ounces total would have been about right. With my measuring syringe plunger melted from previous MEKP usage, I had to count out the 64 drops in each 4 ounce batch for a 2% mixture. With the ambient temperature at about 78 degrees in the shop, this worked out to about 45 minutes until the gel coat started to set (just right)…except that I got antsy after examining the gel coat in the cup that had solidified and was concerned that I would run out to time (in reality – I probably have hours before the gel coat cure would be affected). That brings us to the first blunder; I started to apply glass too early and ended up rubbing away some of the gel coat on the stern. Second blunder; I didn’t prepare / precut enough fiberglass and working with random mat was horribly messy once my gloves got resin on them. Third blunder, I underestimated the amount of resin required and just barely ran out of resin resulting in a couple of dry spots in the laminate. And the fourth and final blunder, which I think is due to the fact that I had to remove the wax from the plug (wrong type?), is that the plug was impossibly stuck inside the mold.

The good news is that the mold did come out with only one major blunder in one top edge where it was a bit dry and the gel coat was left unsupported. Due to some dry spots in the lamination I don’t think the mold is durable enough for vacuum bagging, but I should be able to repair it enough to pull out a new plug, do some light refinishing, build a second mold, and take a muligan.

Things I took away from this;
1) Don’t get impatient with the gel coat.
2) I’ll spray a test blob on something with equal thickness so I can test it with a finger and not worry about messing anything up.
3) Pre-lay all the fiberglass to reduce the handling.
4) Use a slurry of milled glass fibers and resin to fill in the sharp corners in the mold – the glass didn’t like to bend around the sharp corner and left the one spot unsupported.
5) I might even use the sprayer to lay down a coat of polyester resin on top of the gel coat and start laying glass on that before wetting it out to ensure a void-free layup.
6) Wax the ever-lovin’-crap out of the plug before the PVA goes down.
7) Maybe look at putting in a tiny air port somewhere on the bottom of the hull…like where the rudder post might emerge. This would allow me to pressurize the joint at the point where things stick the worst.

In hindsight, it’s painfully obvious that I have very little experience with wet hand layups … I can’t wait to get to the vacuum bagging part since I actually know what I’m doing there.