Cutting miter on wide plank

[Maurice Arney]

I'm making a small counter area for a kitchen alcove. My counter top will be made of 1 1/2 thick glued up cherry, 18 inches wide. I'm planning an "L" shaped corner for the cabinets along with this cherry counter top. What is the best way to accurately cut 45 degree miters in the ends of my 18 inch plank? It needs to be a tight, accurate miter so as to minimize seam visibility in the counter top. I Bought a set of these to pull the joint tight. https://www.rockler.com/tite-joint-fastener

Thanks!

[joe milana]

Kinda' depends on what tools you have available. If you have a Martin T75PreX, I'd say use that. Hand saw & block plane...yep, that'll work too. Router & straight edge....sure. Track saw? Of course. CNC router? There must be 50 ways...

[Jim Morgan]

I will try to give a useful answer.

I would use a track saw or equivalent, cutting from the bottom if possible to minimize any tearout. Cut the first piece at your best approximation to 45°. Then lay that piece on top of the second piece, ensuring that they are perpendicular to each other. Scribe the cut line on the bottom piece and cut to that line. This way, it doesn't matter if you are a little off from a true 45°.

[Maurice Arney]

Kinda' depends on what tools you have available. If you have a Martin T75PreX, I'd say use that. Hand saw & block plane...yep, that'll work too. Router & straight edge....sure. Track saw? Of course. CNC router? There must be 50 ways...

Yes there are lots of ways. This is why I'm asking opinions on what works best. Thanks for the useless snarky answer.

[Maurice Arney]

I will try to give a useful answer.

I would use a track saw or equivalent, cutting from the bottom if possible to minimize any tearout. Cut the first piece at your best approximation to 45°. Then lay that piece on top of the second piece, ensuring that they are perpendicular to each other. Scribe the cut line on the bottom piece and cut to that line. This way, it doesn't matter if you are a little off from a true 45°.

Thanks James, A track saw was my first thought as well. I think your procedure sounds like a good way to go also. And thank you for a useful answer. :) I have a miter gauge for my Makita track saw so this might be a good time to try it out.

[Paul F Franklin]

Another option would be to cut them close (however), then clamp them with a gap, say just under 1/2" between the two miters and making sure the angle between the two pieces is an accurate 90 degrees. Then clamp a guide to one piece and make a single pass with a router and 1/2" downcut spiral bit, cleaning up both faces and making them mirror images. Because it's a long cut in two pieces at once you'll want to make it a light cut.

Just keep in mind that a long miter in solid wood is pretty likely to open up down the road. You have long pieces at one end of the miter and shorter pieces at the other end. With changes in humidity, the longer pieces will change more in length than the shorter pieces. If the tops are tightly fastened to the cabinets, the miter will be under pressure to open up. Fortunately, wood doesn't move that much along its length, so if you fasten the top with oversized holes to allow a little movement, you should be ok. The fasteners will help; you could also consider gluing in a spline so you have some long grain glue surface, if you were planning to glue.

[Maurice Arney]

Another option would be to cut them close (however), then clamp them with a gap, say just under 1/2" between the two miters and making sure the angle between the two pieces is an accurate 90 degrees. Then clamp a guide to one piece and make a single pass with a router and 1/2" downcut spiral bit, cleaning up both faces and making them mirror images. Because it's a long cut in two pieces at once you'll want to make it a light cut.

Just keep in mind that a long miter in solid wood is pretty likely to open up down the road. You have long pieces at one end of the miter and shorter pieces at the other end. With changes in humidity, the longer pieces will change more in length than the shorter pieces. If the tops are tightly fastened to the cabinets, the miter will be under pressure to open up. Fortunately, wood doesn't move that much along its length, so if you fasten the top with oversized holes to allow a little movement, you should be ok. The fasteners will help; you could also consider gluing in a spline so you have some long grain glue surface, if you were planning to glue.

All good info... Thanks!

[John Goodin]

If the counter is going into a inside corner, it might be wise to make sure the wall is 90 degrees.

[Maurice Arney]

If the counter is going into a inside corner, it might be wise to make sure the wall is 90 degrees.

They rarely are ;)

[Rich Engelhardt]

I'm making a small counter area for a kitchen alcove. My counter top will be made of 1 1/2 thick glued up cherry, 18 inches wide. I'm planning an "L" shaped corner for the cabinets along with this cherry counter top. What is the best way to accurately cut 45 degree miters in the ends of my 18 inch plank? It needs to be a tight, accurate miter so as to minimize seam visibility in the counter top.
Lay one side of the miter down on top of the counters & butt it against the wall. Lay the other side on top and overlap it with the first one.
Strike a line on the first one where the overlap is. Use a knife, not a pencil.

Now take both off and move to your cutting surface.

Lay the two pieces out just as they were on the counter top and line up the overlap.

Put the track saw on to make the miter cut, set the blade to it's lowest setting - 2 3/16" and double cut the two sides. Remove the top piece, place the track on the bottom piece and line it up with the cut & finish cutting.

The two double cut pieces should be a perfect fit & there should be no need to figure out exactly what angle the corner is.


Practice with some scrap......the scrap doesn't have to be as long as the counter top or as thick as the finished pieces,,,but,,the longer and thicker the better.

[Sheldon Funk]

Kinda' depends on what tools you have available. If you have a Martin T75PreX, I'd say use that. Hand saw & block plane...yep, that'll work too. Router & straight edge....sure. Track saw? Of course. CNC router? There must be 50 ways...

Not to be contrary to the rest of the thread but this was a useful answer.

[Jack Cadwell]

Why not make it a butt joint? That would make it look more like real wood, and it wouldn't open up on you.

I made 11" wide mitered door casing two years ago, to match existing. Like the existing, it opened up a lot.

[Maurice Arney]

Not to be contrary to the rest of the thread but this was a useful answer.

Explain to me how this answer is useful. It's kinda like if I asked someone how to get to a city and they said "Kinda' depends on what transportation you have available. If you have a Boeing 707, I'd say use that. Car & pickup truck...yep, that'll work too. Taxi & Bus....sure. Bicycle? Of course. Motorcycle? There must be 50 ways..."

Clearly joe just decided instead he wanted to be a jerk today. Let me explain how this forum usually works... A sincere and considerate response would have been one in which he offered his idea of how to accomplish the task, letting me be concerned with whether I own or have access to the tools he describes. But even then, if his suggestion is to employ a $40,000 piece of machinery, I would still argue he is being a jerk.

[Maurice Arney]

Why not make it a butt joint? That would make it look more like real wood, and it wouldn't open up on you.

I made 11" wide mitered door casing two years ago, to match existing. Like the existing, it opened up a lot.

I never thought of that... Wondering what that would look like. I'll have to google some images...

Did some research and found this https://antiquewoodworks.com/wood-countertop-corners/

This actually doesn't look bad! The "single direction" butt joint looks really nice! Hmmm

[Maurice Arney]

Lay one side of the miter down on top of the counters & butt it against the wall. Lay the other side on top and overlap it with the first one.
Strike a line on the first one where the overlap is. Use a knife, not a pencil.

Now take both off and move to your cutting surface.

Lay the two pieces out just as they were on the counter top and line up the overlap.

Put the track saw on to make the miter cut, set the blade to it's lowest setting - 2 3/16" and double cut the two sides. Remove the top piece, place the track on the bottom piece and line it up with the cut & finish cutting.

The two double cut pieces should be a perfect fit & there should be no need to figure out exactly what angle the corner is.


Practice with some scrap......the scrap doesn't have to be as long as the counter top or as thick as the finished pieces,,,but,,the longer and thicker the better.

This is kinda along the lines of what James was suggesting. I think the track saw is the way to go. Overlaying the joints and using scrap to fine tune. Thanks!

[Maurice Arney]

After googling images of wood countertops, I'm starting to like Jack Caldwell's idea of using a butt joint. :rolleyes:

[John Gulick]

Hand held skilsaw

[Gary Kman]

It's not a question of the joint might open up. A miter in wide solid wood is guaranteed to to open up. While its open stuff will build up in the crack. In the summer when humidity increases each board will get wider. Since the joint is butted on the inside corner neither piece can move there so the outside has to open up and open a lot. Then winter comes and the width decreases. The crack can't close on the gapped side with all the failed fasteners and debris holding it apart so the long point has to pull apart. Try to make it behave with lots of biscuits, steel truss plates or anything else or and the boards will split. They have to. Look at all the work that has gone into doors for hundreds of years to minimize dimension change. They didn't do all that work using hand tools building a frame with floating panels to get exercise. Search for joint shrinkage for pictures.

[Maurice Arney]

Hand held skilsaw

Yep! with straight edge and a couple of clamps. :)

[Maurice Arney]

It's not a question of the joint might open up. A miter in wide solid wood is guaranteed to to open up. While its open stuff will build up in the crack. In the summer when humidity increases each board will get wider. Since the joint is butted on the inside corner neither piece can move there so the outside has to open up and open a lot. Then winter comes and the width decreases. The crack can't close on the gapped side with all the failed fasteners and debris holding it apart so the long point has to pull apart. Try to make it behave with lots of biscuits, steel truss plates or anything else or and the boards will split. They have to. Look at all the work that has gone into doors for hundreds of years to minimize dimension change. They didn't do all that work using hand tools building a frame with floating panels to get exercise. Search for joint shrinkage for pictures.

You are right. I think a "same direction" butt joint is a much safer bet.