JEM Watercraft

Hello all,
I'm in the process of building my first boat. I'm working on a touring pirogue. The problem I'm having is cutting on a curved line. My cuts seem very wavy to me. Straight lines are OK, I just clamp straight edge to the board.
I'm using a jig saw. Is there any secret to staying on the lines for a long curved cut? And more importantly (since I already did all my cuts), how will wavy cuts affect the assembly of my boat?
thanks a lot,

Chris

I cut just outside the line and then sanded/planed to the line - can you still see the line you drew?

I gave up on my jigsaw after my first few long curved cuts. I found that it was very hard to stop the lines from cutting wavy. I would recommend you use a tennon saw, or a special laminate saw or Japanese pull-saw. I bought a laminate saw and it wasn't expensive. You can cut long curved lines exactly centre of the line. Jigsaws are good for tighter curves or cutting hatches etc.

It takes a little practice but you can improve your cutting skills. A quality skill saw with sharp blade makes a big difference. You don't want to go too slow because that will cause more waviness.

What I do is cut my panels, then clamp the mirrored copies together and sand the edges. Takes out much of the peaks.

Stitch and glue is very forgiving and tolerates minor imperfections.

jem wrote:Stitch and glue is very forgiving and tolerates minor imperfections.

Mine were slightly over sized in places and when stitched together there were quite a number of hot spots. The advice was to snip the ties near the hot spot and plane the boards down whilst still on the boat. Worked a treat.

Matt is correct, you can get away with a few missed lines without too much of a problem.

Thanks for the replies. I was getting discouraged.
It's good to know that I can still recover.
-Chris

jem wrote:You don't want to go too slow because that will cause more waviness.

I think that was part of my problem. As I would start to diverge from the line, I would slow down, and it seemed to make it worse.

Earvin wrote:can you still see the line you drew?

I can see about half the lines. the other half I cut over.
This is the technique my dad suggested (after I had already done most of my cuts) and the way I'll cut my next boat.
I keep reminding myself that this is my learning boat.
-Chris

It kind of goes counter to normal logic. But if you keep a steady, even speed, it turns out better.

Part of the problem with my jigsaw is that the blade sets at a slight angle off to the left, so you have to hold the jigsaw at a slight offset to the line you are cutting. Trying to balance all the different factors when following a curved line is quite a job. Maybe if I had a better quality jigsaw to start with (mine is an Ozito) it might have been easier.