This has been a fairly laborious process and one that has increased my respect for the original builders. They had to make and attach five layers of mahogany planks compared to the measly one layer I'm installing.
In my defense, I think it's a bit harder to plank from the inside out than the other way around. The job also would go much faster with two or more sets of hands, but I've stubbornly determined to do every bit of the work on this little crate myself.
The process I've been following is to start in the center of the hull and work my way out to each side. The first plank can go in without any shaping, but each one after that has to be trimmed on at least one side to fit snuggly against its neighbor.
So, to start, I put one plank in position and temporarily clamp/staple it in place. Then I place a second plank alongside the first and scribe a line showing the shape it needs to take for a close fit. Like this:
Below is what the scribed line looks like. It may help to click on the picture to expand it because the edge of my workbench is hard to distinguish from the edge of the plank.
The next step is to bandsaw the plank close to the line. Why not all of the way? Two reasons. The first is that the saw leaves a rough finish that needs to be smoothed. The second is that the scribed line, at least the way I do it (and no matter how many variations I've tried), never ends up a perfect match but always needs fine tuning.
The only way I've discovered to get the right match is to plane the plank close to the scribe line and then hold it in place to see where there are still gaps. I note where the planks touch and plane down those areas a bit more. I repeat this process over and over again until all the gaps disappear. (In some cases, when the curve to be cut on the plank isn't very extensive, I've found it fairly easy to skip the scribing step and just plane the plank by eye).
The photo above show the Lee Nielsen violin maker's plane I have been using for this process. I have it set to shave about 1/200ths inch off with each pass. It takes a lot of passes, but the fit ends up very tight which, for this project, is more a matter of cosmetics than a concern about making the boat watertight. (The reason for this will become obvious later.)
I've settled on installing only five planks at a time because there's almost no way to keep each one from shifting slightly when "gluing" it in. The more planks I install, the more each shift gets magnified from one plank to the next.
The adhesive is epoxy, applied first to the boat and then to the underside of each plank. Here's a picture of a section of the hull coated with epoxy and almost ready for the planks, which are laid out near the bow. I put the epoxy on with a cheap brush with the bristles trimmed more than halfway off. This prevents the sticky epoxy from pulling out too many bristles, which all need to be removed from the surface before the planks are laid in. I use a very slow drying epoxy to give myself plenty of time to get the job done and I change disposable gloves often to keep from smearing epoxy all over the planks and my tools, though I always seem to end up making a mess anyway. I also try not to let drips of my sweat fall into the epoxy.
The last step before fastening the planks is to mix a second batch of epoxy and stir in glass microfibers. This formula thickens the epoxy to a catsup consistency and helps create a stronger, gap-filling bond. It must be evened out with a notched trowel like this (the same technique you'd use when laying ceramic tile).
Once all the "glue" is spread out, I lay the planks in and fasten them in place with staples fired through tongue depressors to hold them down firmly and evenly. I've covered the rest of the procedure in my earlier posts on vacuum bagging.
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