Sunday, 3 June 2007


This pic shows the handle on the screw in day hatch and the cockpit coaming.
The coaming is all fabricated from more 4mm ply. The upstand is visible best in the previous but one pic, when the rim has not yet been added. This pic shows the shape of the completed coaming well.
All of the upstand apart from the 4" at the front is a single long trip of ply. The strip is straight and just under 1" wide. Bending the straight strip into the shape of the cockpit automatically mean that it twisted so as to always end up sticking up at 90" to the deck it was attached to. Very satisfactory - it look much better like his (to me eyes) than standing up vertically all the way round.
The curvature of the back of the cockpit was too tight for even 4mm ply to be bent to dry. A long soaking in hot water added flexibility so it could be bent to fit. Rather than trying to attach a quickly drying and stiffening strip into final position straight away, I roughly wedged it into place with various chocks of wood then left it to dry. I ended up with a dry and stiff again strip in basically the right shape, which was much easier to work with for final positioning and glueing.
It was glued in place inside (rather than on top of) the deck with superglue. This was much easier than using epoxy. Using accelerator means you can hold the strip in place by hand which is a lot easier than trying to devise a clamping system.
The upstand curve at the front was too tight for even hot water softened ply. Commercial bendable ply would probably work. I made my own by using my thinnest (finest kerf) saw to cut parallel lines half way through the a piece of ply. I again used hot water bending and holding in shape until dry to set the rough shape - this time around a paint tin of about the right diameter. A straight strip does not work here. Instead I made the bend ply much wider (and longer) than I needed, and offered it up and cut it to shape after it was dry and holding its curve.
The rim was comparatively easy. It was made in two pieces, one for each side. You could use the same template as for the cockpit opening to get most of the shape apart from the front (with appropriate allowances if necessay for whether the upstand is glued on top of or inside the deck, and whether the im ontop of or ouside the upstand). I just made a simple cardboard template. The very front is quite curved as you can see in the picture - again hot water bending was needed. Not easy as the bend is right at the end of the piece so there is no leverage, bu perseverance paid off. (Could you glue the two sides together first to get more leverage? Yes, if you can be sure that the ends match perfctly. This requires an accuracy basically impossible to achieve with the cardboard template, it can only be achieved with the pieces lined up in their final positions - which needs them to be bent to shape. Catch 22). The rim was glued on top of the upstand, again with superglue.
Being monocoque wood the rim was remarkably stiff already. The whole was further strengthed and reinforced with mini-fillets inside the two 90 degree corners at the top and bottom of the outside of the upstand, and two layers of glasscloth. The glass cloth was applied as bias-cut strips about 12" long.
  • Two very narrow strips - about 3/4" and 1" wide - reinforce the outside of the upstand to hull joint and run most of the way up the upstand.
  • Two similar but slightly wider strips reinforce the outside of the upstand to lip joint, and cove the bottom of the lip. Leave these sticking out past the lip until nearly set, then trim back, but still leave sticking out 1mm.
  • Two much wider strips cover the whole of the top of the lip, inside of the upstand and run round to under the deck. At the outside of the rim these meet with the reinforcement on the bottom of the rim to form a strong fibreglass edge.
  • Note - before glueing the rim in place I'd sanded down the edge so it tapered to about 1mm thick only, to end up with sharper edge to grip the spraydeck and so that the top and bottom fibreglass layers could be made to meet and reinforce the very edge.
This approach to the cockpit rim was much more work than the method Duane recomends for the Point Bennett. Was it worth it? Well, it looks great (I think - check out the shape in he picture above) and is lighter. It was also fun to build. Which would I do if I build another? That's depend on whether I have a deadline to hit!

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