Shaving plywood edges

[rnelson0]

I've got a plywood panel I made to fit an opening but the opening is not square. I need to shave just a bit off one corner. I have a belt sander, but I would not call that a precision instrument (especially since mine is not a variable-speed). Unfortunately, because it's plywood, my hand plane doesn't seem to like it. This is a semi-ancient hand plane that I bought used from my neighbor and I don't think it saw much use, but when I use it on the plywood, it just kind skips over the wood. I think it's because on 1/4" plywood, you've either got opposing grain in the alternating sheets of wood, but could it just need sharpened?

Maybe there's another better way to do this. Any suggestions?

Thanks.

[cabinetman]

You could support the sheet horizontally, Draw a line indicating what needs to come off. Using the belt sander on the edge (so the sanding is up/down), gently move the sander back and forth to the line until it fits the opening.

In using a hand plane, the iron should be very sharp. It should be adjusted down until minimal contact is made, and then increased if necessary. If it's skipping, you may have too much iron exposure, and it may be dull. If held at a slight skew (angle) while moving will allow for a smoother cut.

A straight edge and a router with a trim bit could also be used to trim the plywood.

A hand block sander can be made from a belt sander belt (3 x 21 for example), and a piece of stock 5/8" or 3/4", by 3" wide. Cut the piece so it slides in the belt making the belt tight. It's easy to hold, and you have a large sanding surface on two sides.
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[JR]

Circular saw? It can be very precise for this kind of cut if you use a guide.

JR

[poolhound]

I agree the plane may need sharpening/adjusting. You could mark your line then clamp two solid pieces, one either side of the line and then plane or sand down to it. Would also be a good idea to put a backer piece at the end to save riiping out the edge. You could also use the same setup and flush trim it with the router.

Jon

[rnelson0]

A straight edge and a router with a trim bit could also be used to trim the plywood.

Excellent idea, and an excellent test for my new router and bits. In my defense, I just got them today and I was trying to tackle this problem last Saturday

In using a hand plane, the iron should be very sharp. It should be adjusted down until minimal contact is made, and then increased if necessary. If it's skipping, you may have too much iron exposure, and it may be dull. If held at a slight skew (angle) while moving will allow for a smoother cut.

I was holding it at an angle and I think I had the blade adjusted to the proper depth. I've hand-planed before but it was nearly 20 years ago using my father's plane. I thought it might have something to do with the plywood because the sides seemed to chip but the center wasn't. There's a guy right up the street who has a little sign out front that says "Tool Sharpening". I'll try contacting him soon and see if that helps.

A hand block sander can be made from a belt sander belt (3 x 21 for example), and a piece of stock 5/8" or 3/4", by 3" wide. Cut the piece so it slides in the belt making the belt tight. It's easy to hold, and you have a large sanding surface on two sides.

Thanks, that's another good idea. I am able to support the plywood and run the sander back and forth, but again I would hardly consider that precise - it's easy to take off too much or slope it in either plane or both. Using 60 grit on a small block isn't satisfying either, but with a 3x21 piece of 60 grit it will probably be *just* tolerable enough.

Would also be a good idea to put a backer piece at the end to save riiping out the edge. You could also use the same setup and flush trim it with the router.

That sounds perfect. Hopefully this will let me get the panel cut right the first time. I'm getting tired of bringing it from the 3rd floor to the basement and back over and over to get it just right!

[pelligrini]

In places where I've had to fit an exact cut piece into an irregular place I made a prototype shape out of some single ply cardboard material. You can use multiple pieces taped together. I found it easier than cutting one piece of cardboard 'just right'.

Lay the cardboard on the panel or board (double sided tape is good) and cut up to it.