Dumb question of the week

[Mark Ashmeade]

I'm making a top for a sideboard. For reasons of economy, I want to use a piece of 3/4 plywood, and run a 2" maple border around it.

My issue seems to be accurately measuring the maple pieces, and then transferring that measurement to the saw. Is there an easy way to do this? I can use a miter sled on a table saw, or a RAS. Both cut perfect 45s, the issue is getting the length exactly right, which shows up horrendously if it's off.

I did something similar a week or two ago, and ended up with crappy miter joints. I "fixed" it by running each corner into the table saw blade on a miter sled, and then inserted a spline. It looked fine, but I would rather get it "right" on this next piece. The sideboard is approx 6' long and 12" deep.

[David Thompson 27577]

I've had the same problem on past projects -- still do to some extent.

I solve the problem by vowing to cut long at first. Then I "sneak up on" the correct dimension. I try the piece, shave off a tiny bit, and try again.

"Tiny bit", in this case, might be half a saw kerf, or it might be an amost imperceptible amount.

[Will Overton]

Measure the length and width of the top, precisely. Mark your miter cuts on the maple with the length of the inside (short side) of the board equal to the length of the top. If you are not 100% sure of your measurements, cut strong and sneak up on the final size.

[John Coloccia]

Measure? Why would you do that? LOL. Put the border up against the plywood and strike a line with your favorite knife. When you do your miter, you must leave the inside of that line and only take the outside. Then it's just a matter of splitting that line precisely. There's no trick to it. Sneak up on it. At least you have a line you're trying to hit instead of guessing, or going crosseyed trying to measure 1/64". 1/64" isn't precise enough anyhow, IMHO, and the odds of measuring AND cutting to 1/64" are somewhat poor.

edit: if you need a 3rd hand holding the border to the plywood, I use double sided tape for just about everything, including as a 3rd, 4th and sometimes 5th hand. I get mine from the local Woodcraft. They call it turner's tape because it's strong enough to hold bowls for turning, but will release easily when you want it to.

[Marty Paulus]

I use the sneak up on it method myself. Measure the length cut at least 1/4" long and check fit. Back to mitre saw to shave blade width. Check fit. Back to saw for 1/2 blade cut. Etc. until the joint fits. Then pray for no shrinkage :cool:

[david brum]

There is an excellent article on just what you're asking about by J. Peter Schlebecker in the latest issue of FWW. It should still be available at HD, etc. You can also download it if you have a membership.

[Mark Ashmeade]

Thanks all. It seems the method of sneaking up (down!) is the right way, including marking as opposed to measuring. I guess I wasn't clear in the original post, I do mark as opposed to "measure" with a tape/rule.

I was thinking I might glue up at least two sides of the frame to the plywood, and then concentrate on the last one or two sides, that may make it easier than having all 4 sides simultaneously "live". That's been a difficult thing to manage, particularly with a 6' piece.

Like anything else, I guess I just need more practice!

Thanks again for the contributions.

[Myk Rian]

Put the border up against the plywood and strike a line with your favorite knife.
+1. That's the way I do it.

[John Coloccia]

One more hint: when I'm ripping thin strips or doing mitered borders, I put down a little piece of masking tape in front of the blade. I run a piece through, pull it back and then cut the tape right at that point, using the piece I just ran through as a fence. Presto, I have the end of my saw kerf. Line up the scribe mark on your moulding with the end of the tape, run it through and you're done.

99% of the time this give me a perfect fit, but since I'm splitting the scribe mark, every now and then I'm just a touch tight and I have to trim just a touch off. I'm never loose because I never remove the entire scribe mark.

[David Thompson 27577]

[QUOTE=Mark Ashmeade;1559737]......................I was thinking I might glue up at least two sides of the frame to the plywood, and then concentrate on the last one or two sides,........[QUOTE]

In addition to the sneaking-up cut method, I've found that it's helpful to have a scrap of the edging material that's been mitered.

You can then use that scrap when placing the very first mitered piece in place for the test-fits. This way there is no guessing about an odd 64th of mis-placement.

Hold that first corner together on the panel with whatever you have, then go to the other end of the piece to make your mark with the knife.

And yes, I generally attach the first piece (at least temporarily), to enable marking the second.......... and so on.