Building A Pack Canoe - Part 2: Final Form Assembly and Materials Thicknessing

At this time we began to cut up our wood into the proper sized strips. We made a decision to try for a graduated hull thickness. This would mean using 1/8" walnut for the tumblehome area, 5/32" basswood strips for the sides and turn of the bilge and 3/16" basswood strips for the bottom. That meant that, except for the walnut, we would have to cut all of the strips a bit thicker than 3/16" and then thickness them after the fact. We decided to use my Performax thickness sander as I haven't really played around with my Ridgid thickness planer yet and wasn't confident that I wouldn't mess up the nice wood Lady BK had picked out.

I got a real good deal on the basswood from a closeout at the local lumber yard, but I had to take what was left. There were several stained and darker pieces in the mix, but I got enough wood for more than two canoes for $100 so I could afford to let her be choosy. She wanted the lightest strips and picked out five boards that were between 8' and 14' long and of varying widths. Some of the basswood had sap streaks, small knots and splits. All of it but one board had a sideways sweep to the plank that had to be taken out first before it would ride against the fence. That meant striking a line in the position on the plank that would give us the best yield and then freehand sawing it to that line on the band saw. The walnut was all gotten out from a thick plank I had lying around and was too short for full length strips . That meant we would have to cut and glue about thirty 3" long scarf joints before the wood was thicknessed to its final dimension.

I cut the walnut into boards a bit thicker than 3/4" and then planed them flat on my Powermatic long bed jointer. After that, I laid them on their sides and cut out the strips a tad thicker than 1/8". This allowed seven 5' long strips per board. Four boards gave me 28 strips to work with.










Conventional wisdom says that the easiest way to cut the scarfs is to use a jig and a router or electric hand planer to do the actual cutting. I knew that it would take me longer to make the jig and fine tune it than it would to cut all the scarfs out by hand. So I opted for plan "B", with my favorite 2" chisel, an old W.H. Witherby (honed to arm-shaving sharp), as my weapon of choice.

Here is a photo sequence of the proper way to cut a scarf by hand:

I used a small Starrett square to measure and mark a line across the strip 3" away from the end. For illustrative purposes here, I marked the top with a yellow grease pencil, but for all the rest I just eyeballed it.

An initial cut was made about 1/3 of the way back from the end of the strip. This cut allowed me to establish the approximate angle, plus a few degrees of "fudge" factor.








A second cut is made on the opposite side, a bit more difficult since you can't see on the bottom of this cut. A mirror will help, but I really didn't need it.













Both cuts are extended back to the pencil line. Notice that the facets are slightly convex. This ensures that the plane of the scarf will not end up concave which would not make an acceptable glue line.












After a few quick passes with the 2" chisel to flatten the area, I used my Lie Nielsen 102 low angle block plane to smooth out the lumps.














Here is the finished scarf, ready for gluing. From the time I picked it up to clamp it onto the planing board until the finished scarf... 3 minutes. No fuss, no whining router or chips all over the shop. Instead, lots of tiny little shavings that made me hungry for some chocolate.













If I was going to use epoxy for the joint I would want to rough it up a bit with some sandpaper. A short strip of self sticking sandpaper (Carborundum Premium Red is the best made) fastened to a block of 1/2" Plexiglass does the job admirably. I used Titebond for the gluing, so I only included this shot for demonstration.










Here are a couple shots of my lady love learning to do the scarfing. She is battling a bit of tendinitis right now so I didn't push it with her, but she had no problem learning what was needed and she produced a couple of acceptable scarfs in almost the same time I would have spent.










Lady BK felt more comfortable sitting down so she used this vice. I found it easier and quicker to stand and use my small pattern makers vise.















Now it was time to glue all the scarfs. They not only need to be clamped properly lengthwise, they also need to be kept perfectly straight. We did four at a time on a board mounted on top of my main bench. Waxed paper was placed below them to stop them from adhering to the board and small finishing nails were used to separate them so they wouldn't get glued to each other.








Here is a view of the gluing arrangement. I left the strips in clamps while I ate lunch and then came back to do the other four.













Here is a shot of the setup used to thickness the strips. It was a very slow process. I will not use the thickness sander again for this purpose. Not only was it agonizingly slow, it left a collection of fuzz on the edges that took a lot of care and time to remove with some fine sandpaper (once again, fastened to a strip of Plexi).










Another view of the sanding operation. I was only able to put about six strips through at a time. Not only does the machine lack the power to do a bunch in one pass, the thickness from one side to the other varies by about .010" in spite of every attempt to adjust it.

As a little aside, I think this machine is a piece of crap. Another bad thing about it is that the drive belt slips off to the side as you use it. If you aren't careful it will run into the hardware mounted on the side of the machine and get torn to shreds. New drive belt? $40 plus shipping! So you have to stop the machine every ten minutes or so, loosen the belt tension and slide it back to the other side. Pain in the ass to say the least.


We didn't know where to put the finished strips when we had them all sanded, so I improvised with a bunch of bar clamps fastened to the support beam of the house. Worked better than anything I could have built. It is strong, temporary, allows us to see all the strips and they are all accessible from the side rather than having to fish them out of the end.









This shot is mostly so you get to see the station molds attached to the strongback in the background. For some reason, we forgot to take photos of the setup of the molds. We ran battens down the length in several spots to check the whole thing for fairness. At this time, we discovered to our horror that if we raised and lowered the station molds so that they were all the correct height and were plumb, the tumblehome edges on the molds did not line up to a fairly placed batten. There was no work around for this and it meant that each mold would have to be ever so slight off from plumb and that the peaks of the "vee"s along the keel line would not line up perfectly. We have a work around for that when the time comes to fair it all out, but it was either set them up so that the tumblehome edges were fair or re-draw and re-cut all of the station molds, simply not an option here.

Here is the final shot in this section. I have attached the stem mold and have screwed down the stem to it and am now cutting it to length with my Japanese ryoba saw.













Next...

In Part 3 we we cover the initial stripping of the sheer line, the stripping of the tumblehome area and the establishment and cutting of the tumblehome edge.

Cheers