Wednesday 30 March 2016

Decks glassed, cut

I put in a long day on this part, since I wanted to not have to do any washing and sanding between coats, putting the next coat of epoxy on while the previous part was still tacky.
 
To keep the sanding and filling of the edge to a minimum, I did what Andrew told me about: I put masking tape where I wanted the cloth to overlap to:
And cut the glass with a utility knife along the top edge of the tape when the resin was still "green":
It worked well.

Here's the cockpit opening being cut out more, new shape on the left:

Now the aft hatch opening is cut out as well:

What you don't see is the hull-deck joint being filleted and glassed on the inside. A fair bit of work was required using long-handled tools to reach into the nether regions in the ends of the boat where no-one will go or see, but needing be done for integrity of the build. I used a large LED flashlight for light, with the boat upside-down or on its side.



Friday 25 March 2016

Decking complete, baby born

Before I put the aft side decks on, I made some hanging knees and installed them at the after end of the future hatch opening:
This is looking forward, at the aft side of the cockpit bulkhead. The temporary pink foam form is there to keep the deck angle consistent. The green tape was unnecessary. I wanted to keep splash off the untreated foam, but there was none.

One side deck on, the other gooped and ready:
Like my advanced-design stool? :-)
 
Aft side decks on:

A baby boat was spotted alongside its mother near Victoria Harbour:

I started two amas to my intermediate design, out of doorskin for now, so I can see how they go without too much outlay. I wanted to see the two sizes together. The ama looks small to me at this point. It could be longer, but I don't want it deeper, as it will drag.

I like how similar the bow shapes are:

The whole ama:
Just wired together for now, cross-piece screwed on to hold the top open. The ends are identical. The placement is wrong here, though: the top of the ama will be closer to the sheer line of the main hull, and the ama will be farther out from the main hull. I'm guessing the akas (what we used to call cross-beams) will be 7' long.




Wednesday 23 March 2016

Decking + new ama shape

The foredeck formation was perfect. Here's the foredeck going on top of epoxy goop on the top edge of the hull sides:
Trimmed:
Gradually filling the gap where the two sides meet at the apex.

I stuck some stringers on the edges of the aft deck flat, with a cross-beam at the aft end of the hatch opening (the end pieces are temporary):
A layer of glass went on the underside of the deck, then a layer of carbon fibre tape went down the middle of it:
The left side will be cut out and made into a hatch opening after the deck is installed. I need it there now to hold things in their proper places.
Here it is, installed:
The hardest part was reaching in to put a fillet with glass tape on the transom-deck joint. I could just poke my head through the widest part of that opening to see the transom. Since it was either my head or my arm that went in there, I had to do that joint blind. But looking in, I see that I did a stellar job. I wet the glass tape out in advance on the table, put the goop in with a round-end stick, and pushed the wet-out tape on, smoothing it out with my gloved fingers.

Next came the aft side decks:
The cockpit opening will be widened and rounded more, after the deck gets glassed.

The underside of the aft side decks got a layer of 4-oz glass cloth:

Ama, Ama—Who's got the Ama?

Here's the latest model of the ama shape. It's half-way between the first one and the second. The first had a straight bottom for four of its six feet, while the second was entirely curved with no straight on the bottom. This one has two feet of straight, with two feet of curve on each end:
I like that this one mimics the shape of the bow of the main hull. The extra flat on the bottom gives more buoyancy compared with the one that's all curved.




Wednesday 16 March 2016

Foredeck formed

Ran into a little problem when trying to bend the foredeck into a vee: in a few places, the edges of the panels were bonded where the resin had run between. I kinda hope that happens when I'm doing a butt joint, but I forgot to predict it for this. I ended up cutting the foam right beside the resin that joined the edges, making a new edge. The glass tape did not rip, as I had thought it might. In fact the whole thing was remarkably sturdy with just the one layer of 4-oz cloth on it; I could wave it around and the joint didn't move.

I put two lengths of 3" carbon fibre tape in the bottom of the vee. One was cut into two pieces lengthwise, one wider than the other, so there are three layers of the carbon tape in the centre of the vee. Also two layers of 2½" glass cloth, one under and one over. John says this boat is massively overbuilt (now he tells me!), reminding me that every little bit adds to the weight. It's true it's getting heavier, but I'm under no illusion that I'll be able to lift it with one hand—let alone spin it overhead. ;-) And I would like it to be sturdy rather than flimsy.

 I also put a single layer of carbon fibre tape athwartships right at the forward end of the cockpit, and another forward of where the forward bulkhead will be, to stiffen and strengthen the decks. After all, this boat is meant to sail, and the deck will be the upper support for the mast.
Tomorrow that stick comes out.


Decks started

Whew! All the sanding, filling, fairing, glassing, sanding, etc., and the outside of the hull is finally done—for now. Washing, light sanding and painting are next for it, after the deck is done.

As you can see from the photo below, the deck ridge beam didn't go on right: there shouldn't be a space there, the foam should rest on the beam all the way forward. So the plan is to do a carbon fibre-reinforced joint instead (more about that below).
(See how smooth and shiny that hull is!)
To get the shape of the decks, I taped the straight edge of the ¼" foam to the deck ridge beam:



I let the foam lie against the sheer, crawled underneath, and marked around the sheer:

The same was done for both sides, then they were easily rough cut out with a utility knife, as the foam has no glass on it yet:

(chipped corner gets cut out for cockpit opening)



Cut out & lying where they'll go:


Below: I plan to put the deck pieces in the vee-shaped form you see in the background, and make the carbon fibre joint at the bottom of the vee, the decks resting in the form. This is the inverse of the deck, and allows me to use gravity to advantage. The ridge pole will be cut out when the deck is ready to go on.
I realized I had to glass the inside surface first, which will help to stiffen it, as the ¼" foam is a bit floppy on its own. The glass should bend at the centre seam. If it breaks, I'll tape it on the other side to hold the vee while the carbon fibre centre beam gets made, on what will be the underside of the deck.




Friday 11 March 2016

Fussing

Putting glass tape on the chines:

The outside of the hull is now glassed and faired. The whole hull got one layer of 6-oz cloth; the bottom plank got another layer of 6-oz, and all the corners got two layers of glass tape, one 2½" and one 2". I sanded down all the edges of the tape and feathered them with thickened epoxy. The edges won't be noticed as steps now, but there will be a bump on each corner where the planks meet. The added glass and epoxy inside and outside the corners creates strengthening, stiffening lengthwise "stringers".

Today the bottom got two coats of epoxy, using a spreader and tipping with a brush. The second coat went on after the first was cured to "sticky", so no washing and sanding between coats.

The rest of the hull got two passes of thickened epoxy applied with a spreader (spatula) to fill in the weave of the cloth. Some light sanding and it's ready for paint.

For the skeg, I was going to use an off-cut from Godfrey's cedar rudder that I used for the Firefly—but I thought it was too thick. I liked the idea of it thick and shaped more, but it was out of proportion with the boat. So I used some nominal 1" cedar and stuck it on with thickened epoxy. I'll put fillets & glass between the hull and the skeg next, to support it.





Friday 4 March 2016

Glassing

Washing, sanding, glassing. The drudgery of it all!

You do end up with something unique, though.

Inside done for now:
 

Filling & sanding corners:

6-oz glass draped over the whole hull. I lifted the hull up from the saw horses so the cloth could hang off the edge. Resin applied to bottom:

Resin all over; time to double the glass on the bottom:
(A little roughly cut!)

3" & 2" tape on bottom corners: