Wednesday, May 28, 2014

The Zip takes one step closer to reality

Last night, I assembled the breasthook and stem assembly for my Glen-L Zip. From my previous experience of having built stems and breasthooks for two other boats, I decided to use a different technique this time.

In the past, I would assemble the two pieces of the breasthook and let the epoxy cure. Then, later on, I would attach the completed breasthook to the stem. This time, I assembled all three pieces together at the same time, using only one batch of epoxy.

The reason for doing it this way was to avoid having to deal with the bead of hardened epoxy that forms along seams where the epoxy is squeezed out from between two parts. I’ve learned that it’s a good idea to scrape away any squeezed-out epoxy before it cures by using a small, flexible putty knife. Still, if a bead of hardened epoxy forms on an inside corner, (such as in the notch of the breasthook), it can be difficult to remove. It can also cause problems when you’re fitting pieces together.

By putting all three pieces together at the same time, this problem is easily avoided. 

I decided to assemble the breasthook and stem with the same batch of SilverTip epoxy that I was using to encapsulate limbers and underside parts on the Utility. Not much epoxy was required for this small bit of encapsulation. I had a small amount of #2 silica ready to add to the remaining epoxy when I was done. The Zip parts were disassembled and staged, ready and waiting for the epoxy.

Limbers & underside parts of the Utility needed to be encapsulated before I attach the bottom planking. I won't be able to reach these places once the planking is on.

All the Zip parts set to go: stem, mixing cup for epoxy, kitchen scale in a freezer bag, chip brush, screwdriver, putty knife, awl, small container for #2 silica, mixing stick, rag, and both parts of the breasthook.
After encapsulating some small areas on the Utility, I mixed the silica with the remaining epoxy to thicken it for gluing. I spread this mixture on both mating surfaces of the breasthook and on the top of the stem as well. I used an awl to quickly align the holes on the two parts of the breasthook, and screwed them back together. Then, I fitted the breasthook onto the stem, pressed it down firmly, and used two 2.5-pound weights to hold it down into position. Then I scraped away all the epoxy squeeze-out with the putty knife.

The Zip's stem
Stem and breasthook assembled, waiting for the epoxy to cure. These parts are all made from 3/4" marine-grade Douglas Fir plywood.

Sunday, May 25, 2014

Completion of dry-fitting starboard bottom.

With the first forward panel dry-fit, and the Raptor staples sanded off the transom, the next tasks ahead of me were:
  1. Decide how to finish the transom.

  2. Fit one of the aft panels.

  3. Drill & screw the remaining holes in the forward panel.
I had originally planned to stain the transom before fiberglassing it. This is mainly because I felt that Meranti had too much of a dull brown look to it. I wanted the bright finish to have a good bit of red. I was having a hard time finding the right type of stain to do what I wanted. I was also beginning to get the idea that staining and finishing plywood is a bit different than staining and finishing solid stock. Another boatbuilder, with far more knowledge about woodworking than I have, convinced me to at least try a large sample swatch of epoxy over some un-stained Meranti to see what I thought. I did, and was happy enough with the result that I decided to abandon the idea of staining it first.

Un-stained Meranti with a layer of SilverTip epoxy.
Un-stained Meranti with a layer of SilverTip epoxy.
Next came fitting one of the aft bottom panels. Compared to the front, this was quick and easy. Since the aft end of the forward panel is so far back on the boat, the aft panels only needed to be 33 inches long. I cut 33 inches off of one of the full-size sheets of plywood, then cut that in half. I used the factory-cut straight edges to align the panel on the keel’s centerline and to butt up against the forward panel. It fit together very well & I started placing screws every 6 inches, just like the forward panel.

Aft starboard bottom panel fitted into position.
With both pieces fit, and the overhanging edges trimmed down considerably, I looked for any humps or hollows along the surface. Fortunately, I did not see any that I could discern with the naked eye. So, I decided not to shim the chine any on this side.

Thankfully, I did not see any visible humps or hollows on this side.
Lastly, I placed all the remaining screws in the forward panel. Now, there are screws located every 3 inches, so I will not have to worry about trying to do that at the same time as I epoxy the panel down permanently.

The next step will be to remove the forward panel and use it as a template to cut the forward port panel.

Tuesday, May 13, 2014

Raptor staples? WHAT Raptor staples?

While pondering my next move on the bottom planking, I finally got around to trimming and sanding away the rest of those Raptor staples on the transom. It just took a few minutes, and I was done. Those things sand away in seconds.

I’ve hand-sanded the transom with 220 grit, and am currently smoothing it with 400. I’m trying to decide what I want to do about staining the transom before fiberglassing.

Monday, May 12, 2014

Finally, the first bottom panel is dry-fit.

In the end, I wound up not removing the panel to trim it after all. Instead, I trimmed and fitted it in-place. This method is a tedious and painstaking process, but I found that it worked quite well. The key, as with so many aspects of building a boat, is to take your time.

A “multi-tool” oscillating saw is really an indispensable tool in this process.

First, I had to tackle the transition joint. This really wasn’t too difficult. I had already determined where to place the transition joint, and had sanded & filed its portion on the side planking. Using the crayon-marked line on the inner surface of the bottom planking as a guide, I marked and cut a perpendicular line near it’s aft end. By sheer accident, I got very lucky, and this perpendicular cut wound up being dead-on for the transition joint. 

The crayon-marked line on the inner surface of the panel shows the position of the side planking.
The next part of fitting the transition joint was to cut away enough of the horizontal line to begin fitting the butt-joint between the bottom planking and side planking. I did not have enough working room to cut from the inner surface outward. So, somehow, I had to transfer that crayon-marked line to the outer surface of the plywood. To do this, I simply used my handy spring clip. I clipped it onto the edge of the plywood, then visually aligned the clip’s edge with the crayon line, then marked the plywood along the clip’s outer edge with a pencil. I used the multi-tool to cut along this line, and to remove the excess bits of plywood. I continued this process, about 1-1/4 inches at a time, until I had enough cut away to fit the plywood to the chine and screw it into place, forward of the transition joint. I used the multi-tool saw to bevel the plywood edge as needed for fitting.
Next thing you know, the transition joint was done.

Fitted transition joint.
From there, I used the same “mark, cut, fit” procedure, inch-by-inch, all the way to the stem. I continued to place screws with plywood washers every 6 inches along the chine, stem and keel. It took a while, but in the end I was pleased with the fitting.

The panel's fitting along the underside of Frame #2. So far, so good...

Making inch-by-inch progress forward of the transition joint.

Almost ready to fasten to the stem.

Finally fastened to the stem.

Overall, I was pleased with the fitting along the chine.

I was also pleased with the fitting along the faired surface of the stem.