Sunday, January 27, 2008

Canoe Gondola: Changing (Saw) Horse Midstream

I cut out the second upper panel piece of the canoe today, again using the circular saw. This cut did not go very well. The blade kicked back a couple of times, resulting in nasty edges like this:

Again, I'm sure glad I'm not working with $300 worth of wood!!

The blade retention nut also worked its way loose again, which besides being somewhat scary interrupts the cut and causes another rough spot in the edge when I start again. When I got to the bow, I just made a rough cut, thinking I'd go back with the jigsaw and clean it up:

That worked very well:

As I was trying to hand sand away the messy edge the circular saw had made, I got to thinking that it really strains credulity that the jigsaw could possibly be any worse, and that I ought to give it a try on the next piece:

As you can see, the fear of a wavy edge was well founded, so I anticipate using every bit of the 1/4" latitude promised by the designer:

On the plus side, in addition to being marginally easier on my aching back since I didn't have to get down on my knees and fight my way down the cut with a recalcitrant circular saw, the jigsaw made a much cleaner edge and a lot less of the burning wood stench I get from the circular saw. Well, to be fair, the cleaner edge aspect only lasted right up until I got to the last inch of the bow and the part broke away because I hadn't thought to go back and support it with the sawhorses as I cut past them:

That was easily remedied, and I learned a lesson about supporting the part better as I cut. Well, partially learned the lesson, anyway, as we will soon see.

The edges from the jigsaw cut are a bit wavier than the circular saw edges, and it remains to be seen if this is an acceptable trade-off for the cleaner, easier cut:

So, what did I mean about only partially learning the lesson of moving the sawhorses to support the areas that I had already cut? Well, I sure didn't see this coming, did I:

When I lined up the two bottom pieces, I found that something had gone horribly awry somewhere:

When I flip one of the pieces over they match far more closely, so the error is not in the tracing or cutting, but in the initial measuring or outlining. I can go ahead and build it this way, but the boat will most likely have an inherent banana shape to it. I'm tempted to do it anyway since 1) it's within tolerance, and 2) just to watch hilarity ensue as Co-pilot Egg struggles to figure out why she can't keep the darn thing straight! Actually, stretched across a 14' boat doing 3 mph, I'm not sure it will matter very much. Decisions like this, in a nutshell, are why I should probably never build an airplane!


  1. "A gondola is long and narrow, with an asymmetrical outline to facilitate propulsion with a single oar,"
    this is a quote from the wiki. you could pass off any error as advanced engineering to make it easier to row for one person. it is after all a cheap boat how much engineering can you expect should be your line if it does not work.
    leon c

  2. You may have already considered this, but I'll give it a shot.

    The burning wood smell left by your circular saw makes me wonder if the blade is sharp enough. I had the same wood-burning effect when cutting thin laminate flooring recently, especially when cutting into the middle of a plank (rather than starting at an end).

    I replaced the original blade that came with the saw with a carbide-tipped combination blade -- it honestly felt like a brand-new circular saw after the change.