Sunday, February 28, 2016

Glueing bottom of hull

Bottom of bow section
The Gorilla Construction Glue seems to work fairly well so far. I ended up using up almost the entire tube for the stabilizer floats and the deck, hull sides and bulkheads, as well as attaching the bottom of the bow section of the hull. A little excess glue ended up squeezing out here and there, but it was readily wiped off with a paper towel.
As can be seen from the top photo I used a variety of heavy objects and some clamps to form the 2 inch thick bottom piece against the other part.
After the bow section set and a fresh tube of glue obtained ($7 at Ace Hardware) the middle and rear sections were attached. Additional glue was used as a filler/caulking agent where gaps appeared between the pieces.
Bottom of central and stern sections
Once everything had set I then ran the orbital sander with shop vac attachment over the sides of the hull to remove high spots. This might have been a mistake. The alternative would have been to have filled in the low spots with some lightweight filler, say a mix of resin and microballoons, plus some light sanding. That would have potentially kept the hull shape a little more consistent, but would have added weight.
Glue has set
Regardless, the weight of the hull at this time is about 10 pounds. The fore deck wave splitter still needs to be added, which will probably be another 2 or 3 pounds, and then the glass will add a bunch more.

The bottom edges have also been sanded to a nice curvature (more towards the bow, less towards the stern. This was pretty quick and easy to do with a sanding block and long, even strokes. Yes - a longboard would probably work better to keep things more even, but I don't have one (yet).

Monday, February 15, 2016

Skeleton is taking shape

Side View Amas
Top View Amas
Progress is being made. The amas have been shaped and sanded, and they are ready for their skin to be applied.

The main hull has also been generally defined. It will be 21 feet long, 10 inches wide at its widest, and 6 inches thick in from the front of the cockpit to the just behind the seat. The bottom of the bow is 4 inches above the lowest part of the boat, and the stern will be 3 inches above the lowest part of the boat. There will be extra volume starting at the bow and ending before the cockpit to help keep the bow from burying itself in the waves when surfing.

Bow and cockpit sections, upside down
Side of hull at bow, checking for gaps
The skeleton of the boat is Foamular 250 "pink" foam insulation I picked up from Home Depot. There are two different thicknesses being used. Two inch thick foam is being used for the bottom and for the interior bulkheads in the cockpit area. It is also being used for the joining the three sections of the hull. One in thick foam is being used for the sides and top of the hull, as well as the fore and aft hull bulkheads.

Bow, cockpit, stern bottom and deck
The hot wire cutter was doing a lot of cutting today!

As an aside, it looks like I bought at least two extra panels of the 1 inch insulation. It doesn't look like more than one sheet will be needed for the added volume for the bow above deck.

Once the hull is glued together (using Gorilla Glue), the edges and the hull bottom will be shaped with a hand block sander.

My order for fiberglass, resin and pigment also arrived today. I had hoped to get 40 inch wide 5.6 oz S2 glass, but Fiberglass Supply was out of stock. They suggested substituting 30 inch wide 5.6 oz S2 glass, and I agreed. I'll just have to wrap the hull a little differently than I originally planned, which will put overlaps about every 27 - 30 inches down the length of the hull. Those overlaps will act like ribs and help stiffen the boat even more.