Cutting square holes in 12mm ply

JayBee

Member
Joined
15 Sep 2004
Messages
860
Visit site
I am building some lockers in the forecabin and need to cut some clean and square holes in 12mm ply for the locker doors. Hopefully, I will be able to use the cut out sections, with suitable edge mouldings, as the doors themselves.

My trial runs with a jigsaw on a piece of scrap ply have not been too successful. Even with a top quality blade, taking things easy and running the saw along a fence, the blade does not stay exactly vertical and tends to wander in the cut.

Although I have never used one, I am beginning to think that a router might be the answer. If so, what type of bit would be suitable for a clean cut with minimal waste?

Any other ideas and all advice much appreciated. Thanks
 

narcer

Member
Joined
25 Feb 2005
Messages
171
Location
Mallorca
Visit site
Hi,

Try the same method with a steel straight edge clamped on and cut it with a Fein Tool (osscilating blade) - no probs for 12 mm ply.
 
Joined
25 Feb 2010
Messages
12,982
Visit site
A router will certainly do it.
There's more than one way to do it but I would use one of these;
http://www.trend-uk.com/en/UK/productlist/3/3/trimming.html

First roughly cut out the panel using your jig saw. Then clamp on a straight edge. Then use the cutter (the ball bearing pressing against the straight edge to ensure that everything is straight). You'll end up with a small radius at each corner which you would need to chisel out if you want a sharp angle. If you then want a small radius along the cut edge use one of these; http://www.trend-uk.com/en/UK/productlist/4/59/Bearing_Guided_Ovolo_and_Rounding_Over.html

If you get the Trend catalogue http://www.trend-uk.com/en/UK/ it has a lot of useful information...and it's free! Trend is not the cheapest, but probably the biggest in the business

Practice beforehand. Routers are not tools to take out of a box and merrily put to use. In the wrong hands they are nasty, finger removing, brutes! Always, always, always, go "against" the cutting direction. If you go "with" then the cutter digs in and the whole router takes off, taking your fingers and anything else with it. It's difficult to explain here.....you'll learn first time you use it!!!! In the right hands they are very useful indeed...but still potentially brutal.
 

chewi

Active member
Joined
8 Oct 2007
Messages
1,805
Location
Poole
Visit site
Unless you're happy with a router they can be frightening.

How about this instead
clamp a stright edge say 1 inch sq. along the face side of the cut and tenon saw alongside it, rubbing the saw against the edge at least until you break through ( longer if you prefer) Stop cutting at the corner,leaving the underside partly uncut Then finish the cuts with the the jigsaw (or hacksaw) .

That way the tenon will keep your cuts straight and gentle, the guide will keep them in line and the jigsaw will only have to break out the corners.

You prob. already have all of these.
If you like, treat yourself to an electric tenon. you might use it more then a router.
 

sailorman

Well-known member
Joined
21 May 2003
Messages
78,864
Location
Here or thertemp ashore
Visit site
I am building some lockers in the forecabin and need to cut some clean and square holes in 12mm ply for the locker doors. Hopefully, I will be able to use the cut out sections, with suitable edge mouldings, as the doors themselves.

My trial runs with a jigsaw on a piece of scrap ply have not been too successful. Even with a top quality blade, taking things easy and running the saw along a fence, the blade does not stay exactly vertical and tends to wander in the cut.

Although I have never used one, I am beginning to think that a router might be the answer. If so, what type of bit would be suitable for a clean cut with minimal waste?

Any other ideas and all advice much appreciated. Thanks

a good quality jigsaw will work ok you might cut from the reverse side to minimize breakout
 

monkfish24

Active member
Joined
24 Apr 2003
Messages
1,597
Location
Cornwall
Visit site
Hi,

Try the same method with a steel straight edge clamped on and cut it with a Fein Tool (osscilating blade) - no probs for 12 mm ply.

What Narcer said.

I bought one and they are amazing! It's much better than a jigsaw for making straight lines.

I've done tons with this tool. Bosch do one which is cheaper.

http://www.google.co.uk/products/ca...=X&ei=jFipTcL_Hcmi8QP-qcm4Ag&ved=0CDkQ8wIwAA#

This is the fein version but gives a good demo on what it can do.
http://youtu.be/nynD2SfyINU
 
Last edited:

ean_p

Well-known member
Joined
28 Dec 2001
Messages
3,012
Location
Humber
Visit site
use / hire a top of the range Bosch jigsaw with Bosch blades (even Makita don't compare!) or use / hire a small deep throated bandsaw....... easy peesy....
 
Joined
25 Feb 2010
Messages
12,982
Visit site

JayBee

Member
Joined
15 Sep 2004
Messages
860
Visit site
Thanks for all the helpful replies so far - plenty to think about.

Having somehow achieved a really good fit to the teak faced front panels of the lockers, with accurate compound angles, bevels and so, I am a bit paranoid about cutting four big holes in them.

I have tried using a good quality jigsaw with Bosch T308B clean cut blades. There's no problem with breakout, but no matter what I do, it leaves a slightly wavy cut and/or a bit of a bevel on the edge of the ply. I have googled this problem and it seems I am not alone (for once :)).

The Fein Multimaster or the Bosch version looks like a good bet. I don't suppose my local hire shop will have one of these, so I may have to add to my growing collection of little used power saws of various descriptions and prepare for a bit of domestic flak. :eek:

The purchase of a Fein would certainly ratchet up the expense. The way things are going it might have been cheaper to give the job to a professional, although at boatyard prices, maybe not.

Perhaps chewi's tenon saw would be the way to go.

Thanks again for the feedback - any more would be welcome.
 

Wansworth

Well-known member
Joined
8 May 2003
Messages
30,835
Location
SPAIN,Galicia
Visit site
Err from a bodger.....dont worry too much about cutting exactly frame the hole and the cut out as you suggested will look ok and avoid probs unless you have problems cutting mitres now that is a problem.....
 

Poignard

Well-known member
Joined
23 Jul 2005
Messages
51,732
Location
London and Brittany
Visit site
Err from a bodger.....dont worry too much about cutting exactly frame the hole and the cut out as you suggested will look ok and avoid probs unless you have problems cutting mitres now that is a problem.....

Yes - a nice bit of hardwood moulding covers a multitude of sins!
 
Last edited by a moderator:

ThreeSummers

Active member
Joined
12 Jul 2006
Messages
2,077
Location
Walker Bay, South Africa.
Visit site
My trial runs with a jigsaw on a piece of scrap ply have not been too successful. Even with a top quality blade, taking things easy and running the saw along a fence, the blade does not stay exactly vertical and tends to wander in the cut.

I think this depends on both the machine and the blade. I can cut perfectly straight lines with my Bosch GST 135 as long as I use a small (as in narrow in the fore-aft direction) sharp blade and go s-l-o-w-l-y with a fence.

I find the broader blades tend to 'tuck under' (for want of a better description) more than the narrow ones. I've cut up to 16mm...

Regards,

Tim.
 
Top