Friday, May 13, 2016

Utility and Zip updates: Varnish & Mahogany

— The Utility —

I sanded the deck with 220 grit sandpaper, in an effort to level off some of the ridges of epoxy that were left from squeegeeing the 2nd coat. I decided that, for the third coat, I would simply roll on the epoxy as thin as I possibly could, and leave it to cure.

Once I rolled on the third coat, the epoxy had tons of air bubbles in it... a byproduct of rolling the epoxy. Left as-is, the surface texture was likely to be rather rough. I did not want to ruin one of my good brushes by using it to "tip" the epoxy. So, what I wound up doing was  passing the roller very gently over the surface of the epoxy a few times. The effect wasn't as clean as the regular "roll and tip" method, but it worked well enough.

Surface of the deck after lightly sanding with 220 grit.

Surface of the deck after lightly sanding with 220 grit.

Surface of the deck after 3rd coat of epoxy.

Surface of the deck after 3rd coat of epoxy. You can see a FEW air bubbles, but overall... not bad.

From some angles, you can clearly see the 8oz fiberglass tape in the center of the deck. Perhaps I didn't sand it enough? Perhaps I should have stuck to my original plan of covering the whole thing in 4oz deck cloth?

From other angles, the fiberglass tape is all but invisible.

Once the epoxy had cured for a full 24 hours, I again sanded it lightly with 22o grit. I wanted to knock down the few air bubbles that remained, before coating the deck with its first layer of varnish.

Half the deck sanded, in preparation for varnish.

Deck after its first coat of varnish.

2nd layer of varnish on the port quarter knee.

One thing I learned when I used my varnish brush for the 2nd time was that I had not cleaned it sufficiently. The bristles were extremely stiff. Fortunately, I was able to work them loose enough to use a 2nd time. 

The second time around cleaning the brush, I used more mineral spirits to fully saturate the bristles. I also worked longer at cleaning the brush. I found a good video online from Jamestown Distributors, showing how to clean varnish brushes. It's a great reference, so I'll share a link to it here:

Video on how to clean varnish brushes

— The Zip —

Another great thing I've been watching on YouTube lately is a superb video series on building a Glen-L Zip. If you're interested in building a Zip, or if you're interested in building a boat in general, I'd certainly recommend watching this video series. It's detailed, in-depth, and is currently up to 26 videos, and counting. Here's a link to the first one:

I got pretty inspired by the series, and have learned several things from watching. So the other day, while on a routine trip to the cardiologist, I stopped at a local lumber supplier and bought another board of mahogany. Since I've got the transom drawn out, and the 2 side frame members cut and shaped... I thought I'd continue working on the transom.

With an improvised fence, I'm ready to cut the Zip's motor board.

I decided to start by cutting the motor board. It's important to me that I cut the motor board and the bottom frame member from the same piece of wood, so that they will be the same thickness. If they're not the same thickness, then I will have to cut a notch in the transom knee so that it will fit properly. I'd rather not do that.

One of the thing I learned from watching the video series is that I can get a cleaner, straighter cut with my circular saw if I use some type of improvised fence. I measured the distance from my circular saw blade to the outer edge of the shoe: exactly 1–1/2 inches. 

After drawing the line across my mahogany board for the transom motor board, I drew another line exactly 1–1/2 inches away. I lined up a straight piece of 2x4 (left over from building my motor stand) on this line, and clamped it into place. Then, using that as a guide fence for my circular saw, a straight, clean and accurate cut was quick and easy.
Preparing to trim half an inch from the motor board.

The Zip motor board, as designed, is 12 inches wide x 11 inches high. My mahogany board is just over 12.5 inches wide, so I needed to trim off about half an inch. Again, I improved a fence with a small piece of pine, and the cut was clean and easy.

One last note on the Zip: After I had coated the Utility deck with a 3rd layer of epoxy, I had just enough epoxy left over to finish adding a 2nd coat to the back of frame 5-1/2.

Zip frame #5-1/2

Current Status of Zip Parts
Stem & Breasthook Assembly2 coats of epoxy
Frame 5-1/2Forward face has 3 layers of epoxy. Rear face has 2 layers.
Frame 4Side members cut, but have not been planed or notched for sheer.
Transom KneeCoated with 3 layers of epoxy
Transom FrameSide frame members cut 1/4" oversized on outer side. Motor board cut.
TransomTransom drawn onto 1/4" BS1088 Meranti plywood.

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