How to cut perfect miters

[Cullen Parish]

So I am about at my wits end with this. I am trying to make a humidor with mitered corners. the box is about 4-1/2 inches tall the sides are 13/26 thick, I would prefer them thinner but this is the wood I could get so I am working with it. I originally tried making these cuts on the miter saw with the parts laying down with half of the cuts on one side of the blade and half on the other, thinking that if I was off just a little that they would add up to 90. However this did not work, there were gaps. I then moved to the table saw and tried to tilt the blade and dial it in. Again no dice, my table saw is kind of old. So do you guys have any suggestions on how to make perfect miters. When I search all I get is things for picture frames which aren't appropriate for what I'm doing or links to miter boxes for hand saws.

Thanks guys

[Lex Boegen]

There are a couple of tried-and-true ways of dialing in a miter joint. One way is to use a hand plane to trim the joint, using a shooting board. Of course, this is only as accurate as you make your shooting board.

Another way is to cut the sides slightly oversize, and put them together to form the corner. Use a square to ensure that the corner is a true ninety degrees (don't worry about the gap). Then put a handsaw in the joint and saw down through it. The saw kerf will trim both sides of the miter at once and leave you with a perfect-fitting joint. This technique is easy to do, but you might want to practice it on scrap first (like any new technique).

[Myk Rian]

How are you checking the angle of your saw blades in relation to the table top?
If that is off, you'll never get a true joint.
I use a Wixey gauge to set blade angle. I don't believe the saw gauges are anywhere near accurate.

[Bill Huber]

I had somewhat the same problem when I made my firs box, they just didn't match up right.

I then made a sled for the table saw to cut the 90s, after a test cut or two I got it on and then when I cut the box everything was just fine.

I have not tried this but some people say its the best way to go. Get a 45 degree chamfer bit and do the final on the router. Again I have not tried this but people say it works great.

http://www.rockler.com/product.cfm?page=2124&filter=router%20bits

[Glen Butler]

Myk has a good point using the wixey to get your angle on the TS perfect. It's what is use too. Bill's idea of the 45 degree chamfer bit is good also. But with either idea you need to have a miter slot and jig that is set up to a true 90. You can also use a backer board that is at a true 90 you can run along the fence, but this is a little more dangerous cause you are trying to hold two pieces in unison.

[Willard Foster]

When cuttung on your tablesaw, make sure you have a firm grip on the board so it doesn't move left or right. I have a piece of sandpaper on the face of my miter gaige to increase friction. I found that the wood tends to get "sucked onto" the blade ever so slightly.

The only other advice is to make a lot of practice cuts when setting up your saw before cutting your "good wood".

Good luck, we're all pullin' fer 'ya.

Bill

[Jay Jeffery]

I have not tried this but some people say its the best way to go. Get a 45 degree chamfer bit and do the final on the router. Again I have not tried this but people say it works great.

http://www.rockler.com/product.cfm?page=2124&filter=router%20bits

If you wanted to get serious, you could use a lock miter router bit (http://mlcswoodworking.com/shopsite_sc/store/html/smarthtml/graphics2/TM26-29lockmtr0911.pdf). The technique used with this bit involves running one side with the face on the table and the other side with the face on the fence. I guess if you did that with a chamfer bit, your router table would not need to be 100% aligned.

[Leo Vogel]

Cullen, the two sides (or four for a square) have got to be EXACTLY the same length. If they are off ever so slightly, the completed angles will be off. Willard was right. Use sandpaper on the miter gauge, and hold firmly. Even better, clamp the wood to the gauge. Close will not work, must be exact.

[johnny means]

I assemble three sides first then sneak up on a perfect fit with the last side. This way I can see any discrepancies and compensate for them on just one part.

[John Coloccia]

Just get it close, then use some deck screws to pull it tight. Don't worry if it's not exactly square. Whoever you're making it for should appreciate the effort, and if they don't, well they don't deserve something nice anyway. Don't worry about the gap. Just fill it in with some TiteBond or epoxy. I should mention that I usually use pine for this sort of stuff because the TiteBond blends in better. I don't know what kind of wood you used, but beginners tend to use wood like cedar, and stuff like that. Let me tell you, NOTHING blends in with cedar. Pros, like me, know that you should always use pine. Be sure to remember to tape over the joint so all the glue doesn't run out. Usually, I leave the cap off my TiteBond to thicken it up a bit....you know, to make it less runny. I don't know why they can't just ship it ready to use.

I usually leave it to dry for a couple of days. Sometimes, I have to give it another coat of TiteBond. That's OK...be patient. Quality takes time. Once you're done, though, you'll be rewarded with an heirloom quality....er....box sorta' thingy....that, uhm...I dunno....I guess you can put it on the TV and throw all your junk in it when you get home from work, or something like that.

Glad I could help. Happy building!

[Myk Rian]

Just get it close, then use some deck screws to pull it tight. Don't worry if it's not exactly square. Whoever you're making it for should appreciate the effort, and if they don't, well they don't deserve something nice anyway.
Deck screws? Not exactly square? You are kidding, right? Have you no "Pride in Accomplishment"?


Don't worry about the gap. Just fill it in with some TiteBond or epoxy. I should mention that I usually use pine for this sort of stuff because the TiteBond blends in better. I don't know what kind of wood you used, but beginners tend to use wood like cedar, and stuff like that. Let me tell you, NOTHING blends in with cedar. Pros, like me, know that you should always use pine.
Cedar blends in with cedar. Fill in the gaps? Once you get good cuts, there are no gaps. Pros use every species of wood there is.


Be sure to remember to tape over the joint so all the glue doesn't run out. Usually, I leave the cap off my TiteBond to thicken it up a bit....you know, to make it less runny. I don't know why they can't just ship it ready to use. I usually leave it to dry for a couple of days. Sometimes, I have to give it another coat of TiteBond.
If deck screws are used, you don't have to worry about glue squeeze out.
Tite Bond is ready to use. It isn't meant to be a gap filler. How do you give a joint another coat of Tite Bond?



That's OK...be patient. Quality takes time. Once you're done, though, you'll be rewarded with an heirloom quality....er....box sorta' thingy....that, uhm...I dunno....I guess you can put it on the TV and throw all your junk in it when you get home from work, or something like that.
Glad I could help. Happy building!
An Heirloom box made with deck screws and runny glue. Hardly a Pro job.

[Fred Belknap]

Just get it close, then use some deck screws to pull it tight. Don't worry if it's not exactly square. Whoever you're making it for should appreciate the effort, and if they don't, well they don't deserve something nice anyway. Don't worry about the gap. Just fill it in with some TiteBond or epoxy. I should mention that I usually use pine for this sort of stuff because the TiteBond blends in better. I don't know what kind of wood you used, but beginners tend to use wood like cedar, and stuff like that. Let me tell you, NOTHING blends in with cedar. Pros, like me, know that you should always use pine. Be sure to remember to tape over the joint so all the glue doesn't run out. Usually, I leave the cap off my TiteBond to thicken it up a bit....you know, to make it less runny. I don't know why they can't just ship it ready to use.

I usually leave it to dry for a couple of days. Sometimes, I have to give it another coat of TiteBond. That's OK...be patient. Quality takes time. Once you're done, though, you'll be rewarded with an heirloom quality....er....box sorta' thingy....that, uhm...I dunno....I guess you can put it on the TV and throw all your junk in it when you get home from work, or something like that.

Glad I could help. Happy building!

John you left out one rule.
If it don't fit get a bigger hammer:D

[Jerome Hanby]

If you wanted to get serious, you could use a lock miter router bit (http://mlcswoodworking.com/shopsite_sc/store/html/smarthtml/graphics2/TM26-29lockmtr0911.pdf). The technique used with this bit involves running one side with the face on the table and the other side with the face on the fence. I guess if you did that with a chamfer bit, your router table would not need to be 100% aligned.

I've been fooling around with a lock miter bit. If you have the correct size (looks like you need the size that will handle 1/2"), a router table setup with a fine adjustment for the router height, a cheap depth gauge ($1.36 at Amazon (http://www.amazon.com/gp/product/B0015YHDPA/ref=oss_product)), and some playing cards then they aren't too bad to get dialed in. Check out woodshop demos for the procedure. Just a small part of the wonderful legacy the owner left us.

[John Coloccia]

Here's how I do it, by the way. I cut both angles on two opposit sides of the box. Use the same setting for all four cuts. Then fiddle with a piece of scrap until you get a cut that will give you 90. Make the other four cuts and done.

Just how I do it.

[Thomas Allan]

Personally, even with the other excellent suggestions here, I'd spend the time necessary to adjust or fudge the miter saw until it makes perfect cuts (or get one that will).

Sometimes on cheaper saws or tougher woods the blade and/or arbor tend to deflect some even when in good adjustment (especially on bevel cuts), it sometimes helps to cut slightly over-sized and then re-shave a sliver.

Remember, your miter saw can be set to any bevel or miter, if your cut is off it's actually your 'reading' that is wrong, and/or possibly your detent(s). Even when I set my SCMS in any of it's detents, I 'lean and lock' it to a certain side within the detent itself.

If your saw has no adjustment (and it probably doesn't), you can still shim on an alternate fence right to the front of your existing fence that's perfectly perpendicular to your existing detent setting, and if your bevel is off you can shim under your piece if necessary.

Once your saw is in good tune-up and perfect alignment, you're set for all future cuts, so it's unquestionably time well spent.

[Paul Murphy]

One option is to build a seperate cutoff sled for use with the tablesaw blade tilted at 45 degrees. All the same rules apply, such as get the fence square using the 5-cut method. You will have to ensure the blade is truly at 45 degrees to the sled/saw surface before every use, so something like the wixey electronic angle finder will help.

In the end, you have to accept the requirements of what you are trying to accomplish. Your opposing sides have to be exactly the same length in addition to having exactly square end cuts at exactly 45 degrees. Your stock will have to be flat, and of the same thickness.

As another poster advised, you could also use a shooting board and well tuned plane, just ensure the opposing sides end up at equal lengths.

Finally your glue-up needs to happen on a flat surface. If you induce a twist in your box through a twist in your clamping surface you will have gaps even in joints that were otherwise perfect.:eek:

[Ron Jackson]

Wow.....this post has just given me a REAL taste of REALITY !! The intended owner wants " Just a little square box for what-nots". A simple request that on the surface is a "piece of cake"..... I guess that I've been building custom humidors and jewelry boxes for so long, that I have lost sight of the check-list of things that go into the construction of "Just a little square box". Now, as I see all of these posts and start to think of everything that can go wrong, I more easily see how it can become overwhelming and frustrating to even professionals. I needed to start another box today, but now I think I need a couple more cups of coffee...

[george wilson]

Carbide blades tend to "push wood away" as they cut a 1 sided cut,like trying to make a miter joint fit. You'd best make a jig to trim the miters at 45 degrees with a sharp plane.

[Terry Wawro]

Just get it close, then use some deck screws to pull it tight. Don't worry if it's not exactly square. Whoever you're making it for should appreciate the effort, and if they don't, well they don't deserve something nice anyway. Don't worry about the gap. Just fill it in with some TiteBond or epoxy.

You and your fancy deck screws. I just dab on some liquid nails and clamp it overnight. The next day I fill in the cracks with Bondo, wait a while for it to set up, then sand my new masterpiece smooth. After that I paint it black with a rattle can to blend it all together.


Just kidding of course.:D

Getting a tight miter is hard. Dialing it in depends on a lot of factors. Your getting some real good advice here.

[Paul Murphy]

Wow.....this post has just given me a REAL taste of REALITY !! The intended owner wants " Just a little square box for what-nots". A simple request that on the surface is a "piece of cake"..... I guess that I've been building custom humidors and jewelry boxes for so long, that I have lost sight of the check-list of things that go into the construction of "Just a little square box". Now, as I see all of these posts and start to think of everything that can go wrong, I more easily see how it can become overwhelming and frustrating to even professionals. I needed to start another box today, but now I think I need a couple more cups of coffee...

I was even wearing my glasses:cool:, so I'm pretty sure this is what I read:
"So I am about at my wits end with this."
"So do you guys have any suggestions on how to make perfect miters."

However, if all the fellow wants is "Just a little square box for what-nots", then get out the drywall screws, plugs, putty, and belt sander!:D

[Karl Card]

I just watched a dvd on this yesterday. can remember the guys name but he ade a little jig that you use on you table saw and actually cuts a perfect jig every time. what happens is you cut one piece of wood on the left side of the jig and the other part of the corner on the right hand side of the jig..tha way if there is any difference at all the other side will pick up the difference in the cut. looked so easy and neat i gotta have one soon;...I dont know if i can explainthe jig but ill try . just a piece of wood any comfortable size really then on top you screw a 90 degree angle dead center then screw the 2 pieces together, careful to make sure nuts on the undersize ore sunk. then with your fence you line up the middle of the jig and make a cut about 1/4 or 1/2 way thru the jig, then line up your corner marks on the wood and cut left on the left and right onthe right of the jig...perfectomundo

[Lee Schierer]

I used to use plastic drafting triangles and then make test cuts until I got two sides to equal 90 degrees. Now I use my Tilt Box Digital Angle gauge to get the blade close and still do a couple of test cuts to insure I'm exactly at 90. I also cut all my side pieces about 1/4" long to start and then dial in the angle until I can dry assemble all four pieces to get gap free corners, then I trim the four pieces to the exact length needed.

Exact length of opposite sides is essential for a good fitting corner. When gluing, use plenty of glue as you are essentially gluing an end grain joint so it will suck up more glue than a face grain joint.

[Terry Beadle]

To the jig use or shooting board, you can use postit notes, the small ones about 1 inch square, to stick to the sides or bottom of the jig or shooting board. This useage is something I saw on David Charlesworth's great DVD on shooting boards. You can also use plane shavings in a pinch.

By placing one or more postit notes, on the jig sides or bottom, near the cutting end to raise the angle or towards the non angle end to lower the angle, you can dial in a perfect 45. I like the shooting board design Mr. Charlesworth suggested. Attached is a picture that shows better than I can explain.

Enjoy!

[Michael MacDonald]

Just get it close, then use some deck screws to pull it tight. Don't worry if it's not exactly square. Whoever you're making it for should appreciate the effort...........


this made me laugh... I think another equally helpful suggestion might be to just face glue a bunch of boards up, and then carve the box out of the center... voila, no miter gaps.

I read the thread not because I had any great suggestions, but to pick up some tips. I recently cut some angles on a table saw to make a pentagon, and that was really tough... I think part of my problem was I was using the stock miter gauge. I also found out that my blade-tilt axis was not parallel to the table, so I shimmed the contractor saw trunnions a bit. I haven't yet had to cut miters since, but I hope to see an improvement next time.

[Dave Anthony]

I use the tablesaw with a sliding table, if I did not have the table I would build a cross cut sled. Adjust the saw to 45 degrees, there should be adjustable stops (mine has allen set screws on the top of the table). Cut scrap & adjust the angle until a drafting triangle or T square shows you've reached 45 degrees, as close as you can measure it. Tighten the stop, return the blade to 90, make a test cut, adjust the stop as necessary, back to 45, test, etc. You should be able to set up the saw to cut a true 90 and true 45 each time based on the stops. Build a cross cut sled and ensure it cuts a true 90 degrees using the 5 cut method. Add stop blocks to the sled so that you can cut to exact lengths. Use a sharp blade and cut all miters with the inside facing down. I went through the same thing. It seems like a lot of effort, but it's worth it. Once you have your saw set up properly and a good cross cut sled cutting the miters is not a problem, though issues can still arise during glueup. Without proper setup & tools this is surprisingly difficult, particularly if you are striving for a perfect grain match.

[Ray Newman]

Cullen Parish: even thou I have a SCMS, I prefer to cut my miters on the TS. It is habit.

The “TS Method”:

--Adjust the TS insert to ‘dead-nuts-on’ level to the TS top.

--After leveling the insert, adjust the blade to 45 degrees using an accurate square. Key here is having an accurate square.

--Take a 12” or so piece of flat/straight scrap (an inch or so wide will suffice) and take a cut. Place the square with the blade extended approx. 10”, hold it up the light to see how accurate it is. No light along the blade length and the miter and the saw is set to go.

--If necessary adjust the tilt. If/once the 45 degree cut is true, install a wooden subfence to the miter gauge, leaving about 5-6” extending past the blade to act as a sweep to remove cut offs from the blade. Make a cut through the subfence.

If you want, install fine sandpaper to the subfence to hold the work in place, or just clamp a wood bloc to the subfence and holding down the work.

--Make cut on one end and check. If OK, make the other cuts.

Best to first cut the longest prices first, then cut the shorter. You can make short pieces from long pieces, but not vice-versa.:D Repetitive cuts are easy by lining up the cut mark to subfence kerf and installing a stop block to hold the work to the proper length.

[Jeff Willard]

You and your fancy deck screws. I just dab on some liquid nails and clamp it overnight. The next day I fill in the cracks with Bondo, wait a while for it to set up, then sand my new masterpiece smooth. After that I paint it black with a rattle can to blend it all together.


You guys should be ashamed of yourselves:mad:. You aren't helping this feller at all. He comes here seeking to tap our collective knowledge and experience, to learn and grow, and you turn it into a big dang joke. This isn't what "The Creek" is all about.

'Sides-everbuddy knows this is what "hide" glue is for. Just mix it with a little sawdust and smoosh it (technical term meaning mash) into the gap:eek:.

Seriously though, were it me, I'd take the handplane/shooting board route. Allows you to creep right up on it.

[Myk Rian]

If it were me, and I was making a box to toss stuff into, I would use a locking rabbet joint and be done with it. Much stronger than a simple miter anyway.
http://www.sawmillcreek.org/attachment.php?attachmentid=134827&d=1260494362

[Steven J Corpstein]

Cullen,
Sounds like others have gotten off track with your question and their answers. If I were building a humidor, I'd want it to come out square also. People spend hundreds of dollars on those things to store even more expensive collections of cigars.

I've had the best luck making sure that my four pieces are dead on the correct length. They also have to be the same thickness and have very square ends.

Then I use a 45 degree router bit with bearing and trim them off with the bearing just touching the edge lightly. You can lay all four side by side with a scrap piece of wood on each side to prevent tearout, and put the 45 on all four at once. Then just flip and repeat....good luck with your project.

[Cullen Parish]

Thanks for all the help guys. The miter saw which I got used was a little off. The back fence was off a little also the height of the rotating part of the table was a different height than the out stationary part of the table. I adjusted the fence and compensated the height with masking tape and it came out pretty good.

I would have used the box joint but I wanted a more finished look for the humidor. and I also considered the locking miter bit but I don't have a router table yet, I'm working on that too.