Completing the underside of the deck

Couple things were up for this week: I cleaned up the excess hybrid hanging over the edge of the gunwale.

Once that was done, I applied protection patches on the underside of the deck wherever a soldier or t-soldier would hit the deck. I also put a strip down under the mast. A couple notes on this:

• The pieces were circles six inches in diameter. Rounded squares would have been as good (and easier to cut).
• Don't sand down the surface too far.
• It probably would have been better to put a blue dot on the glass, and a red dot on the hull exactly where the centre of the glass should be - then you just align the two dots, and all is good.
• There should have been the same protection patches on the hull. Oh well.

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Glassing the inside of the deck

Got everything ready for glassing this week, and even did a couple other things.

First, I figured while I had the hull upside down, I might as well fair out the underside of the transom bar. (This is hard to do right side up because the epoxy drips.) The stern edge and the bottom took most of a three-squirt cup. I mixed in 1/2 tablespoon graphite powder and a whole lot of 407 fairing filter (thus the grey colour).

Next, I cut the hybrid. I laid the piece down on the garage floor - a well vacuumed floor - but another possibility would have been to suspend the roll on a line and pull it off. (I mention this when doing the hull.) The floor worked well; three cuts and I had the deck ready to go.

I decided I wanted to fair in the bow area a bit more; there were indentations on the inner edges the hybrid wouldn't have easily filled.

Next up, I did the actual sanding work on the transom bar. Because of all the 407 I added, it sanded very easily - and the resulting surface is very fair. It looks awesome. I sanded into the underlying glass a couple times (particularly on the gudgeon), but overall I'm happy with it.

I had an evening to burn, so I figured I would make backing plates for the chainplates and spinnaker rail. This involved about 10 layers of scrap s-glass and two layers of scrap hybrid: layers 2 and 9 are hybrid, and the outermost and most of the inside layers are s-glass. Most of my layers had some overlap of some kind (i.e. they weren't entirely 12in x 12in pieces of solid glass). I laid this all out, put in plenty of epoxy, covered in plastic, and clamped. Trim the edges, and all is well. The most interesting bit of this was that the plastic, which had a crease, left the impression of that crease in the finished product - despite all the clamping pressure. Something to watch out for when building centreboards.

Finally, it was glassing time. I trimmed the hybrid before the epoxy this time (the hull was different). We pulled 8 10-squirt cups, and wound up needing another three for the entire deck. I went through and poured in the initial application of epoxy and wet out the hybrid; then Max came back through and removed excess epoxy.

Once the entire deck was wet out, we added in the carbon tape along partial bulkheads, along the centreline up to the centreboard trunk, and made an X with tape between the chainplate location and the mast step. I wet all these out with epoxy/206 (or 205) and painted them on, then pressed them down with a squeegee.

After that, I went back along the gunwales with a brush and painted the hybrid on to the gunwales. This worked perfectly - I had debated not putting the fillet until after the hybrid; that wouldn't have worked nearly as well.

Then wait a couple hours and apply a second coat (epoxy/205 this time). I used a regular 1/4" fuzzy nap roller for this coat. At this point I stopped on the hull, but there were still a few unfilled spots on the deck, so I did a third coat, this time with a thin, 1/8" West System foam roller (and again epoxy/205).

Overall it went very smoothly. I wish I had had Max over for the topside of the deck. I remember now Bram had said when we glassed the exterior of the hull "having two people makes this a lot easier - I'm having you over when I have to do this next". There was very little outgassing - perhaps only four or five bubbles showed up which we had to remove. There are a couple spots where the hybrid pulled away from the step - mostly in the angles. But overall it looks great.

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Filling holes on the deck

And so I began the long process of gap filling the underside of the deck. I learned from the hull that it's worth spending time filling bubble-generating holes. This surface gets a layer of hybrid, and it's really hard to see bubbles in hybrid - so eliminating their source is worthwhile.

First I filled the gaps in the darts in the wings. These had a bunch of unevenness, mostly because the three different woods had slightly different widths. Epoxy/407 mix did the trick. Both side of darts needed at most two squirts, and around two spoonfuls of 407. (407 has the strange property of seeming to never get to the mayonnaise stage - since it's a fairing filter, you might expect it to stay runny, so I suppose that make some sense. But when you apply it in thin layers, you realize you added too much...)

Then I did a third application of epoxy in the staple holes, and sanded it down.

Next up was a full sealer coat. Sealer coat epoxy doesn't add any strength, and I'm just filling in gaps. So I added 407 to the mix. The 407 seems to stop the epoxy from sinking all the way through to the wood, so I should need less epoxy. This entire side took 15 quirts of (the interior of the hull took 24). I did it in batches of five, and batch I added two spoonfuls of 407.

Once cured, I marked all the bubble locations, so I can return later and re-fill the bubbles. Sand. Another coat, this time focused on the bubble locations.

Next up, I cut an "inverse fillet" tool, and filled in the groove between the mahogany and cedar strips with a nice rounded edge.

Sand everything down again. Almost there.

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On gluelines

I've talked a bit about glue lines before. I still have some glue lines in the completed, glassed deck. I've come to the following conclusions:

• Glue lines are impossible to remove. Avoid them like the plague.
• The only way to remove glue lines is with the scraper, which also hacks away at your wood. Sanding tends to sand down the cedar instead of the glue, and so you have to come back with a scraper anyway.
• When you install a strip, on the visible side you should see absolutely no glue squeeze out. If you do, you put too much glue in the cove of the strip. When applying the glue in the cove, there shouldn't be a bead of glue, there should be a thin film.
• Better too little glue than too much, since the cedar will be encased in epoxy and glass anyway.
• You should use tape to pull together adjacent strips everywhere - everywhere. My wings don't have many glue lines - and almost all the strips there I used tape to pull them together. This slows down building, but you get better results.
• Scraping away rock hard glue leaves dings all over the cedar. Best is to wait until the glue forms a thick skin, and remove it then.
• Wiping away wet glue smears it all over, which is then sucked up by the cedar, leaving a "glue smudge". If there is extra, wait until it forms a skin (but is not rock hard) and remove it then.

VMG solved this problem by not using glue at all - they gave all their strips a pre-coat of epoxy before assembling them on the forms. Makes for pretty results...

Deck removed from the forms

I removed the deck from the forms (just like the hull before it) and began work on the underside. I started out by scraping everything down and taking off all the dribbles of glue. Next, I sanded everything down with 60-grit, but quickly switched to 40-grit (when I realized how long 60-grit would take...) Already after a single sanding pass many of the station lines had started to disappear.

I figured I would spend a bit of time cleaning up the front edge of the step. This was mostly work with the rasp; rasp off the initial bit and then switch to sandpaper to get the right surface.

Next, I put fillets around the edges of the gunwale and the inner edges of the step. This was a pass with epoxy/405, and I used a 1/2" radius washer for all the fillets. Bram did these fillets while the deck was on the forms (from the bottom), to ensure it was strong enough to move. I figured if I was careful I could do them afterwards, and save myself a lot of cleanup time. No problems.

Then I did a bit more sanding and a bit of planing.

Next up, I figured I would strengthen the bond between the gunwale strips. Using a syringe, I laid a line of epoxy down the entire length of the gunwale. This mostly got sucked into the crack, and I came back and re-filled areas which needed it. Gloved fingers can pop the bubbles easily. All the extra I used to fill the screw holes with.

We're getting close now. Another pass with the sander, and I then filled all the big holes I could see with straight epoxy. Then I worked on all the staple holes. For the hull, I used a paintbrush to paint on the epoxy; this time I used a stir stick and pressed it in with a squeegee. I'm not sure which works better; the stick seemed fine. During the first epoxy application for the staple holes, I went back twice over everything - first time the strips soak up the epoxy, return while still uncured and go over a second time to actually fill the holes. I think this worked out pretty well.

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