Plywood passed a "test"

 Two years ago(!), when I bought the plywood for the hull and started the build I threw a scrap piece behind the shed in the muck, where it has been soaking in the rain and drying together with some leaves and mud ever since. This is how it looks like today:

 

No signs of mold, rot or delamination, that counts as good enough where I come from:) I'm not going to do the famous boil test. Not planning on boiling the boat either...

laters

Building the cockpit

 Today was the day I managed to start working on the cockpit. It is not too difficult, the cutting part, but it does require some planning as there are many corners and joints. I'm trying to make sure the joints will be load bearing in the direction that most makes sense for the particular joint.

I have cut out some venting holes:

The surfaces that will be walked on (and jumped on from the cabin top) will be reinforced with some beams - the design specifies 8mm plywood for all surfaces here and does not call for any bracing - I don't know, the 8mm ply seems a bit too thin to leave like that. It will gain some additional strength after it is glassed over, but I'm going to reinforce everything anyway. I will not be installing those before at least drilling the holes for the lower rudder gudgeon as it will be a pain trying to reach the transom through the vents in the bulkhead after everything is closed up.

The whole thing came out very symmetric, I could use the pattern I made for one side for making both pieces with a very good fit so, again, stressing out over the layout and the dimensions of the frames payed out again.

Tomorrow I'll start gluing everything up, but it looks like It will take more than 1 day as I want to cut some more limber holes in the side assemblies.

ciao.

A picture is worth more than a thousand words

Since no progress has been made as I'm waiting for some parts to get delivered (glad I still have that excuse at least), I'll share a link to the album with all the pictures of the build. No explanations, sly remarks or attempts at humor. Just pictures:

Setka Piglet album

enjoy.

Taking care of the cold resin problem

 It's been a while since last I updated my blog. Or even worked on the boat... Time to resume activities. But. Winter is coming. And it's getting cold in the shop.

Mindful of how much I hated working with cold syrupy resin last winter I decided I need to make a heat box to keep the glue toasty and thin. In the spirit of DIY and due to the fact I could not find one that would let me control both the temperature of the box AND the heating element (maybe they are there, but i'm sure they are expensive) I decided to make one. The heating element temperature needs to be limited for the obvious reason of not melting a plastic jar of resin, that would just be counterproductive. And I want to be able to use whatever heater I have at hand: light bulbs, whatever. I do happen to have a 200W printer heat bed, but that also likes to get pretty hot.

Requirements:

- Fun. Check. That has been had. The geeky kind.

- Cheap. Not sure if in the end it actually was cheap(-er) than commercial options, but hey, see point 1.

- Silent. None of that clickety-clack of mechanical relays. Hence a cheap chinese SSR comes into play. It is rated to 25A, I would not trust it beyond 10, in reality it will not control more than 1 or 2. Should be aok.

- Safe. As in: not melting down anything. Not the resin, not itself. So the temperature of the heater must be under control, and the temperature of self (as in: the solid state relay) must be kept in check. And since the latter is of the chinesium persuasion and likes to go up in flames - an additional safety (mechanical) relay comes to the rescue to disconnect the whole thing if overheated.

- Modular enough to be easily serviceable. That includes the micro controller - I picked an Arduino pro mini - simple, well supported and cheap.

- Simple interface: just one rotating knob to set everything (temperatures, hysteresis setting, saving defaults and the like).

The prototype (using resistors as heaters pressed against dallas temperature sensors) looks like this:

Instead of soldering everything on a prototyping board (which I considered) I designed a proper(?) PCB and had a well known chinese PCB manufacturer stamp out 5 of them (that is the minimal amount I could order). The boards will be arriving in a couple of days and if I did not make any oopsies in the layout I will have 4 perfectly good spares if anyone will be interested:

The code to go with the setup is published on github. I'm sure there is plenty of thermostat projects out there, but this one is mine and mine alone:)

Now on to trying to finish Piglet's cockpit. I'll post when done (in a few days).

doei.

Bottom's down

I am fed up with fairing and filling holes. I'll finish that later, before glassing the finished hull. I want to work on the interior now. So. I flipped the hull, it's all upside up now.
I used two chain hoists hung from the structure of the tent. I did check the cross braces and other bits, had a trial run hanging myself from every post and it all seemed to hold. I weighed the boat using two scales - the weight adds up to 181kg. that is 90 kg per hoist, that is over 10 kilos less than my test weight:). So I just did it, with my family's assistance.

Once the hull was lifted and weighed, the turning could start. Here's a partial video we made of it, the camera gave out half way, well, that's life:

 From here all that is left to do is clean up the interior, build the bunks, galley, storage, cocpit, deck, daggerboard, rudder, build a mast, order sails (not gonna do it myself), do the deck hardware and a multitude of other stuff.
But first just sit down and think.
ciao.

The hull - finishing touches

I managed to finish working on the stem and I replaced all the temporary fasteners except along the sheer since there will be some beveling going on there to fit the cabin top and deck and I don't want to destroy my tools on steel fasteners buried in the plating somewhere. For the rest: all the stainless fasteners (5x30mm on the chines, 5x35mm on the frames, 5x50mm in the stem and transom, 4.5x30mm along the stringers) are bedded with epoxy, countersunk and the holes filled with fairing compound. Tomorrow I'll sand the fairing compound down and see if any more is needed in preparation for glassing - I'll try to make the surface under the glass as fair as practical since the glass will have to be faired as well.

The trennels I used to replace the temporary fasteners in the stem are quite long as they are tying all the layers together and also bite into the deadwood. The key to success is making sure the glue fully fills the hole and encapsulates the dowel. I drilled 9mm holes for 8mm dowels and filled the holes "from the bottom up" about half way using a syringe and a piece of tube. The under sized dowel then squeezes the glue out along it's sides and voila, no air pockets (to speak of).

Don't have too many photos (working solo with epoxy, no time to shoot), here's the few I do have.

 

I tried to remove some of the stainless screws I used for keeping the turn of the bilge in place to better bed them with epoxy - turns out they were already pretty much glued, despite heating them up first with a soldering iron I still managed to twist off a head or two. I just left those in place, they will be plenty strong.

 ...and here's the hull in various stages of being treated with the fairing compound.

The sanding and final touches tomorrow or so if time allows.
cheers.

The stem cover

The stem in the Design requires an additional plate to tie it together. From what I have seen in others' blogs (including the Designer's) a 3cm plank suffices. BUT. The bow is then just held together by 6cm of wood with the grain running vertically and therefore, theoretically, could split/check. The Design does not call for any other reinforcements (aside from maybe some glass to cover the joint), no wooden crooks, not even steel bolts. I did  consider the latter, but for this size boat it probably is overkill, especially since I'm not aware of any setkas developing a problem at the stem.
For my own peace of mind I decided to reinforce it by laminating some maritime pine with grain running perpendicularly to the stem between the 2 parts of my Douglas fir stem. It does make my boat about 2cm longer than in the Design, but with a little bit of luck nobody will notice ;).

For gluing I used the last of my polish Epidian 5 + PAC combination with a little bit extra hardener (100:70 ratio as I did on the bottom plating) to make the glue a little bit more elastic and impact resistant.  All according to the manufacturer's specification. The cured resin is noticeably less brittle, but still much tougher than wood. Clamping force (not too much) was provided by wood screws and clamps.

The next day I removed the screws (with the help of an old soldering iron, they were properly glued in place). There is only about 3cm of douglas fir they can grab on to, not much point in trying to rely on them as reinforcement. In the leftover holes I will glue in oak trennels.

Also: I trimmed the stem and roughed out the outline of the cutwater. The hull is now close to it's final shape.

Next steps: replace all temporary fasteners with proper ones, fill and fair all the imperfections to prepare for glassing. Which I may or may not do next. But maybe I will first turn the hull upright and do the interior and deck first. We will see.