labr@
13th April 2013, 09:47 AM
I’ve been building a skin on frame kayak over the last few months and while it’s not all timber the frame is relevant to this forum. The design is Jeff Horton’s Curlew, 15 feet long, built from the offsets and other information in his book.
The construction method is to make frames from plywood and lash the stringers to these using artificial sinew. Stringer timber is paulownia and was cut and scarfed into the lengths needed. Ply is ½” hardwood marine.
The coaming was made first as it can be stored easily enough while the rest comes together. It was laminated around a melamine faced MDF form. The timber is mainly from recycled timber blinds – probably basswood – but the lip is western red cedar. It was coated in epoxy as both the timber types are very soft.
First layer on form.
262911
Finished coaming
262919
The frame was built on 4 supporting frames mounted on a strongback. Lashing takes some time but is not hard.
Frame lashed on strongback.
262912
The frame in front of the cockpit rubs against the calves so the bottom was cut out and another half frame was installed under where my knees will go. This also shortens the floorboards so there is not much change in weight.
Photo showsw the new half frame in place before cutting out the bottom of the forward frame.
262913
This is the completed frame outside for testing paddler fitment and accessory placement.
262914
It took a long while to get to the skinning but that was started over the Easter weekend. I pulled a few holes in the fabric but the seams are fairly straight and overall I’m pleased with it.
This is part way through sewing the rear deck seam.
262915
Then it was time to do the ironing - of the skin that is. This shrinks the skin taut and it looks much better after this. There are still some ripples around the coaming but it’s acceptable to me.
Interior facing forward.
262917
262916
Last night the first coat of paint was applied. This is just an oil based exterior enamel. I used something similar on a Sabre dinghy once and it stood up remarkably well. I was tempted to use a clear urethane but my biggest concern is with abrasion so the enamel it is.
After painting I just need to fit the painters and a seat then it will be time for a paddle.
The construction method is to make frames from plywood and lash the stringers to these using artificial sinew. Stringer timber is paulownia and was cut and scarfed into the lengths needed. Ply is ½” hardwood marine.
The coaming was made first as it can be stored easily enough while the rest comes together. It was laminated around a melamine faced MDF form. The timber is mainly from recycled timber blinds – probably basswood – but the lip is western red cedar. It was coated in epoxy as both the timber types are very soft.
First layer on form.
262911
Finished coaming
262919
The frame was built on 4 supporting frames mounted on a strongback. Lashing takes some time but is not hard.
Frame lashed on strongback.
262912
The frame in front of the cockpit rubs against the calves so the bottom was cut out and another half frame was installed under where my knees will go. This also shortens the floorboards so there is not much change in weight.
Photo showsw the new half frame in place before cutting out the bottom of the forward frame.
262913
This is the completed frame outside for testing paddler fitment and accessory placement.
262914
It took a long while to get to the skinning but that was started over the Easter weekend. I pulled a few holes in the fabric but the seams are fairly straight and overall I’m pleased with it.
This is part way through sewing the rear deck seam.
262915
Then it was time to do the ironing - of the skin that is. This shrinks the skin taut and it looks much better after this. There are still some ripples around the coaming but it’s acceptable to me.
Interior facing forward.
262917
262916
Last night the first coat of paint was applied. This is just an oil based exterior enamel. I used something similar on a Sabre dinghy once and it stood up remarkably well. I was tempted to use a clear urethane but my biggest concern is with abrasion so the enamel it is.
After painting I just need to fit the painters and a seat then it will be time for a paddle.