Cutting ply
 

Does anyone have any tips on the best ways to cut marine ply (6, 9 and
12mm)? In particular I want to cut curved 8' boards for a dinghy. So I
guessing that a band saw is a good bet but I don't have one. Are there
any other methods that can produce good results?

Thanks

"Brian" wrote in message
...
Does anyone have any tips on the best ways to cut marine ply (6, 9 and
12mm)? In particular I want to cut curved 8' boards for a dinghy. So I
guessing that a band saw is a good bet but I don't have one. Are there
any other methods that can produce good results?

Pre-saw with an electrical jig saw, outside the lines. Nail a batten down on
the lines and use a router with trimming bit, rolling along the batten.
Makes a Perfect cut.

You can also tack the batten down first and slide the jigsaw aloing it, with
a block screwed under the sole in such a position that the blade cuts about
1/8 to 1/4" from the batten.
See my website at
http://www.customware.nl/boats/en/index.html, look in the diary at February
19 for pictures.


Meindert

I cut gentle curves by hand with a pullsaw.... cuts faster and smoother than
a jigsaw.... but not round *tight* curves.

"Brian" wrote in message
...
Does anyone have any tips on the best ways to cut marine ply (6, 9 and
12mm)? In particular I want to cut curved 8' boards for a dinghy. So I
guessing that a band saw is a good bet but I don't have one. Are there any
other methods that can produce good results?

Thanks

On Wed, 20 Apr 2005 23:08:28 +1200, Brian
wrote:

Does anyone have any tips on the best ways to cut marine ply (6, 9 and
12mm)? In particular I want to cut curved 8' boards for a dinghy. So I
guessing that a band saw is a good bet but I don't have one. Are there
any other methods that can produce good results?

Thanks

A power jig-saw does good work, if equipped with the right blade. A
fine metal blade might be better for thin sheets, which otherwise show
one ragged edge unless backed.

Brian Whatcott Altus, OK

Depends on what kind of saw you happen to have.

An electic circular saw can follow a curved line because the blade only
has to be set very shallow. Use a thin kerf blade with lots of teeth. I've
used a blade with 40 teeth. They make a special plywood blade with many
more teeth but I haven't found it to be any better. The only problem with
a circular saw is they tend to be heavy so the plywood should be well
supported and you have to go slow. I've found the thin blade of a jig saw
(sabre saw) can wander off the line pretty easy to you have to be careful.
You can also try sawing through masking tape to reduce tearing along the
edge. The jig saw and circular saw blades cut on the upstroke so the tape
has to be on the top side.

Brian ) writes:
Does anyone have any tips on the best ways to cut marine ply (6, 9 and
12mm)? In particular I want to cut curved 8' boards for a dinghy. So I
guessing that a band saw is a good bet but I don't have one. Are there
any other methods that can produce good results?

Thanks


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One extra hint. When cutting splintery wood like meranti. Lay a batten
along the finish cut line and score the top side with a crate knife before
starting the cut with an up cutting saw like a circular or jigsaw. It
prevents chipping of the face veneer so you will end up with a much cleaner
edge. Not needed with a reasonably fine toothed a band saw.

Saw outside the line and trim to it with a plane, router or belt sander.
For long slow curves I use a circular saw set just deeper than the sheet. I
do the gross trimming with a power plane and finish up with a low angle
block plane.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Brian" wrote in message
...
Does anyone have any tips on the best ways to cut marine ply (6, 9 and
12mm)? In particular I want to cut curved 8' boards for a dinghy. So I
guessing that a band saw is a good bet but I don't have one. Are there any
other methods that can produce good results?

Thanks

skil saw


"Brian" wrote in message
...
Does anyone have any tips on the best ways to cut marine ply (6, 9 and
12mm)? In particular I want to cut curved 8' boards for a dinghy. So I
guessing that a band saw is a good bet but I don't have one. Are there
any other methods that can produce good results?

Thanks

On the first stitch and glue dinghy I built, I did it slow and carefully
with a jigsaw, and a block plane to finish.

The second I used just a jigsaw.

The third I used a jigsaw and tried to go as fast as possible. Errors
greater than 1/4" were trimmed with the jigsaw. But otherwise it all
got hidden in the tape seam anyway. :)

Nice boat you are building! One day I would like to try something so
elegant.

The idea with the router is so obvious. I have used the same idea for
straight edges with ply in the past and got great results. I don't know
why I didn't think of using a batten and doing curves the same way. I
also like the jigsaw jig idea.

Thanks for this tips.

Meindert Sprang wrote:
"Brian" wrote in message
...

Does anyone have any tips on the best ways to cut marine ply (6, 9 and
12mm)? In particular I want to cut curved 8' boards for a dinghy. So I
guessing that a band saw is a good bet but I don't have one. Are there
any other methods that can produce good results?


Pre-saw with an electrical jig saw, outside the lines. Nail a batten down on
the lines and use a router with trimming bit, rolling along the batten.
Makes a Perfect cut.

You can also tack the batten down first and slide the jigsaw aloing it, with
a block screwed under the sole in such a position that the blade cuts about
1/8 to 1/4" from the batten.
See my website at
http://www.customware.nl/boats/en/index.html, look in the diary at February
19 for pictures.


Meindert

I had not heard of a pullsaw but have read up on them and they sound
worth looking into. The idea of a narrower cut due to narrower blade
makes a lot of sense.

I will keep my eyes open for one in the shops.

Thanks for the info.


James wrote:

I cut gentle curves by hand with a pullsaw.... cuts faster and smoother than
a jigsaw.... but not round *tight* curves.

"Brian" wrote in message
...

Does anyone have any tips on the best ways to cut marine ply (6, 9 and
12mm)? In particular I want to cut curved 8' boards for a dinghy. So I
guessing that a band saw is a good bet but I don't have one. Are there any
other methods that can produce good results?

Thanks