Wednesday, June 16, 2010

Gluing, stitching and more gluing

Because you can't ship 15 foot long pieces of lumber very economically the bottom and side planks, among other components, are composed of two pieces that have to be glued together.
Above can be seen the "puzzle joints of the nos. 1, 2 and 3 side planks after gluing. The shape of the joint makes it a lot easier to join the pieces with the proper alignment.

The stitching process involves drilling a 1/16th in. hole every 4 inches or so along both edges of the bottom and planks and the 3 supports. A 3.5 to 5 inch copper wire is pushed through the holes and hand tightened. Later all the wires are completely tightened with a pliers so all the pieces fit together as tightly as possible. As will be seen that doesn't always work out perfectly, so other methods are used.

Here I've stitched together the bottom and nos. 1 and 2 side planks and have added the upright supports.




All three side panels plus the bottom and supports are now stitched together and tightened as closely as I could. I had to move the stern support forward a small amount for a much better 3-dimensional fit. Some gaps can be seen between the front support and the port side and at the bow stem, but I'm told I can fix this with thickened epoxy later.



Here I'm tacking the bottom panel to the no. 1 plank and using a different mixture in a syringe to tack together between the side planks, avoiding getting epoxy on the wires. The big issue about working with epoxy is the cure time. This particular type needs 24 hours to cure at 75 degrees. For every 10 degrees less you need another 24 hours and you can't work under 55 degrees. In northern Wisconsin 75 degrees is hard to come by most of the year, so you have to compensate by providing a heat source or just waiting longer between steps.


All the tacking is now complete, the epoxy has properly cured and I can begin removing most of the copper wires.



Now I fill in the gaps between the epoxy tacks on the bottom and side tacks and let it cure again.




























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