cutting along a line

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puddy
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cutting along a line

Post by puddy » Mon Oct 24, 2011 4:07 am

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

Earvin
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Re: cutting along a line

Post by Earvin » Mon Oct 24, 2011 4:48 am

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

"It is better to travel well than to arrive".

goanywhere
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Re: cutting along a line

Post by goanywhere » Mon Oct 24, 2011 7:58 am

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.
My psychologist reckons I need lots of fishin' therapy!

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jem
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Re: cutting along a line

Post by jem » Mon Oct 24, 2011 10:50 am

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.
-Matt. Designer.

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Falcn
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Re: cutting along a line

Post by Falcn » Mon Oct 24, 2011 5:59 pm

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.

puddy
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Joined: Wed Sep 21, 2011 3:58 pm
Type of boat I like: Canoe or kayak

Re: cutting along a line

Post by puddy » Mon Oct 24, 2011 9:25 pm

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

puddy
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Joined: Wed Sep 21, 2011 3:58 pm
Type of boat I like: Canoe or kayak

Re: cutting along a line

Post by puddy » Mon Oct 24, 2011 9:28 pm

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.

puddy
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Joined: Wed Sep 21, 2011 3:58 pm
Type of boat I like: Canoe or kayak

Re: cutting along a line

Post by puddy » Mon Oct 24, 2011 9:34 pm

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

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jem
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Re: cutting along a line

Post by jem » Mon Oct 24, 2011 9:37 pm

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

goanywhere
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Re: cutting along a line

Post by goanywhere » Mon Oct 24, 2011 10:47 pm

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.
My psychologist reckons I need lots of fishin' therapy!

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