Cutting square holes in 12mm ply

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JayBee

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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
 
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narcer

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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.
 
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Rigger Mortice

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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

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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

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JayBee said:
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
Click to expand...

a good quality jigsaw will work ok you might cut from the reverse side to minimize breakout
 
monkfish24

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narcer said:
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.
Click to expand...

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
 
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ean_p

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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....
 
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JayBee

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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.
 
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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

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mogy said:
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.....
Click to expand...

Yes - a nice bit of hardwood moulding covers a multitude of sins!
 
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ThreeSummers

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JayBee said:
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.
Click to expand...

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.
 
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