Modifying Simbo

It is a bank holiday here in England, when the banks are compelled to shut up shop so commerce is impossible and everyone can go to play. That is the theory anyway - there does seem to be an awful lot of commerce going on.
But not at chez Partridge, because today Simbo gets finished. The rush to get on the water meant that the interior only got a couple of coats of primer/undercoat and the gunwale got no finish at all.
I am also making a few changes in the light of lessons learnt at the launch.
Firstly, something needs to be done about that tummy, but that is a more long term aim. Can you see how I am having to hold my legs uncomfortably straight to swing the oars back? So the main mod today is to move the rowlocks upwards and backwards to give a more comfortable rowing action. If all goes well Simbo may get wet again this afternoon.

Building Simbo - finishing the structural bits

With the inside fillets well hard, the hull was turned over and lain on two carefully levelled and aligned workmates. The duct tape came off with a deeply satisfying ripping noise (almost as good as popping bubble wrap).
The seams were then taped over, a messy process comprising splashing on a coat of resin, applying the tape, folding the tape over the angle and swearing mightily when it popped back up again. Patience and firm pressure is needed. Finally, another application of resin to fill the weave as much as possible. Leave to harden.
When hard, I pasted on another coat of resin+filler to fill the weave completely and fair the edge of the tape. Again, returning periodically as it hardened allowed runs to be swiped off and sags to be corrected, at least partially.
The seams finished, it was time to add the little decks. The original design has breasthooks, but I happened to have some timber liberated from Bracklesham Beach when a container ship went down a few years back. It was a very simple matter to cut a couple of pieces to size, securing them with epoxy and a few leftover gripfasts.
The original design also has no gunwales, but the thin ply I used meant gunwales were essential. They were glued in place and nailed at the ends. This is where every builder traditionally says "you can never have too many clamps". So there - I've said it.
Then it was sanding, sanding and sanding until I swore a mighty oath of ENOUGH!
I have become a great fan of water based exterior paint for boats, It is so much cheaper than two-pot epoxy paint and you can touch up dings with ease. It dries so quickly you can get three coats on in a day. And washing the brush out in water is such a joy compared with horrible white spirit. Better for the environment too. The only minus is that it only comes in silk finish, so you can't get a yotty sheen.
I just had time (one hour before launch!) to add a thwart in the middle and a pair of rowlocks (both leftover kit from my previous boat Nessy) and it was off to Pulborough.
Tomorrow: lessons learned.

Building Simbo - going 3D

Duct tape, the bodger's friend, got the hull together after a considerable struggle getting long woggly planks to stay in the right position long enough to get the tape firmly fixed. Two pairs of hands are definitely better than one here, and taking some time getting the joints exactly correct is well worth while - Simbo is ever so slightly corkscrew shaped.
The gunwales have a natural tendency to move inboard, so they were held out with a batten secured by more duct tape.

Once assembled, the bottom was secured to what I laughingly call a workbench (a sheet of plywood on a pair of workmates) by a couple of deck screws and a length of wood.
Now all was set for securing the seams, first with a dribble of pure resin, then with a fillet of resin+microfibres mixed in to the consistency of yoghurt. I found it pays to return to the work every half hour or so as it hardens to clean up runs and push the fillet back into shape to stop it sagging. The result was fairly neat.
Then it had to be put under cover again to avoid yet another frontal system sweeping up the Channel. The outside would have to be left for the morrow.

Building Simbo

Having decided to build a small boat for small waters, I started the search for a suitable design. It needed to be quick, easy and cheap. Hannu's Simbo was the obvious choice, as the hull pieces are cut using practically straight lines out of one sheet of ply - it is very clever.
However, Hannu uses 12mm (half inch) ply to eliminate the need for any reinforcement. Unfortunately, this also means he has to build a jig to force the bottom into a curve. And I happened to have a nice sheet of 5mm (quarter inch) ply that Alec Jordan used to protect the kit for the Bee he supplied last year and I still haven't got round to building yet. Alec kindly confirmed that the ply is exterior grade and OK for a boat - so every Jordan Boats kit comes with two 'single sheet' boats free outside!
Using thinner ply also allowed me to adopt a much simpler 'tape and glue' construction using duct tape to hold the bits together for gluing with epoxy.

The first step was to draw the cut lines on the ply, which took minutes, and cutting them out with a regular cross-cut saw - Hannu correctly points out that you have much more control with a handsaw than a powered jigsaw and the lines are much straighter as a result.

I then attached the hull sides together with epoxy and tape, separating them from each other and the work surfaces with builder's plastic sheeting. The joints were clamped down with a pair of decking screws through each end of a bit of scrap timber.
The epoxy was SP, mainly because it is the only brand available in local chandleries, and has a 5:1 mixing ratio. To get it correct, I prepared a measuring glass by putting a sticky label on a disposable drinking cup, filling it with exactly 100ml of water and clearly marking the level. To measure out the hardener I used one of those little 20ml measuring cups you get with cold cures, which are never thrown away in our household.
Construction ceased to allow the resin to cure. Tomorrow: going 3D.