Cutting large holes in plywood?
 

What is the best method/tools for cutting out neat holes for doors in a large piece of plywood?

A drill and a jigsaw may not be the cleanest, but if you don't have a shop its probably the easiest and more affordable way of cutting holes in wood. I'm assuming something like a table jigsaw would be a little cleaner.

If you are certain you can draw the cut out square, you might try dropping in a circular saw for the longest part of the cut then clean up the corners with a jig saw. Use the finest tooth blade you can find to get the cleanest cut, and go slow.

this would be the way to go. also put some masking tape on the top layer so it doesnt chip up.

GO SLOW, i am sure u have heard measure 3 times cut 1. and square everything up befor cutting to save yourself from having to redo things.

Rough cut the hole with the jigsaw, leaving 1/4" or so. Then use a router and straightedge to clean up what is left.

You can use a straight edge with the jigsaw also, but if you have access to the router, it will work mutch better.

+1

A router and straight edge could also be used to make the entire cut. This is especially useful for cutting large, round holes.

I agree with IronMan, as a contractor we use a router, While the jigsaw will work the doors will still have to be trimmed to be able to open, a router with a 1/8 bit will do it all at once. Good Luck.

You can do it with a straightedge, but I prefer to do it with an outside form and a bottom bearing bit (or a router collet).

Just take 4 strips of 1/2 particle board (or whatever you have lying around) and build a full guide. This way you can guarantee square and have almost no chance of making a mistake (as long as you clamp it down tight). Just make sure the frame is square and flat on both sides. A 1/8" bit is fine, just go slowly or you'll risk snapping it off.

And Take pictures

You mean Bean :D

Double sided tape is much easier than clamps :)

Having worked for a boat manufacturer for about 10 years, the method of choice was a hole saw. You can buy generic hole saws up to 5" or 6", good for plywood, starboard, fiberglass that would be my preference.

Bigffish

I agree. Holes saw. I have some at work that I can use for free though. Large holes saws are not cheap.

Ok, this is 3/4" plywood, so I assume I will need a very stout router (2hp+) and will need to take it slow, perhaps only going 1/4" or so per pass....

For round holes that are a reasonable size, sure. But the OP (as he clearly indicated in his first post) is talking about cutting holes for cabinet DOORS :)

You don't need a big router :)

If you have a plunge router, you can likely cut the whole panel out in one pass using the template & guide bushing (or bearing bit) method as indicated above.

That said, if you are not familiar with using a router with templates, then you will spend more time making the template and messing around than it is worth.

As I mentioned, I would rough cut the hole out within 1/8" or so of the finished line using a jig-saw. I would then clamp (or use double sided tape) a straightedge to the panel and use it is a guide. The quickgrip clamps are great for this. Use one straight edge as a guide and another as a STOP so that you don't route too far.

Do you have a router? Are you borrowing or buying?

Will be borrowing or buying. I've been reading a lot on router forums dot com and the Craftsman 2hp combo is pretty well liked there as an inexpensive option especially for the new router owner (I haven't used one since high school, 20 or so years ago). So I'm thinking of picking one up.

A template isn't really needed unless you are making the same cut several times. Just use a straight edge as a guide and clamp it in place on all four sides of the cut. The guide should be clamped at a distance equal to the distance from the base of the router to the edge of the router bit. Then just plunge the bit through the panel and follow your guides. Take it slow and let the bit do the work. You'll be surprised at how easily the router bit cuts through the plywood. IMO this is far more efficient that rough cutting the hole then finishing the edges in a separate step but that will certainly get the job done as well.

Make sure to shoot us some pictures when you're done.:beer:

I suggested the rough cut first for a few reasons:

1) so that he does not have to deal with supporting the waste piece. This will prevent cracking and/or binding when the piece sags as material is removed.

2) less depth of cut means less (or no) grabbing

3) less depth of cut meanns less need to regulate feed rate which lessens (removes) the possibility of burning up the bit :)

If he DOES decide to plunge cut the piece, then it should be done resting on a sacraficial surface and he should use a 1/4" UP SPIRAL bit, not a straight sided cutter.

I insert thy foot into thy mouth:lmao:

Bigffish

If you don't have a great workshop/space, then I second the rough cut and trim method.

If you are buying a router, then I suggest getting one with an adjustable speed feature, and USE IT. Matching your rotation speed to your bit size can make a nice difference in cutting, and prolonging the life of your bit edge.

You are going to try and insert my foot into my mouth, and expect to get away with it? (Old an middle English are dangerous things. Use wisely and with caution.)

I have NEVER posted in a thread without reading the first post... EVER :D

Well maybe a few times :)

Ok, here is another thought. Since this hole on the front of the stand will be the same as the 2x frame perhaps it would be best to do a rough cut with a jig saw and then use a bottom bearing flush trim bit to finish the cut out?

As long as your 2x frame is square and smooth :)

That's true, 2x's aren't as smooth as I'd like it so I'll use the straight edge approach.

Sorry, I wasn't suggesting that your method was wrong. I was simply suggesting another method that I think would require fewer steps. There is certainly more than one way to cut a rectangular hole in a sheet of plywood and any of them will get the job done.:love1: