Best way to tight miters

[Jason Morgan]

I recently made a mirror frame and am generally happy with the result, although I was a little disappointed with the small gaps in the miters. I was wondering what you all used as a procedure for cutting and gluing/clamping miters? I used one of the Bessey band clamps and it seemed to open up at the corners throughout the drying process. By the end, it was okay, but not what I was hoping for.

any suggestions? I guess the real trick is to cut the miters such that only enough pressure to hold the piece together is needed huh? I had thought of glueing each corner separately and then "forcing" the last corner together "by any means necessary"

Thanks,

[Gary Keedwell]

I have had real good luck with the nylon web clamps with the little steel 90º corners. It has a little ratchet that you use to tighten it. I usually do a dry fit to see if my cuts are a true 90º before I glue them. All of mine have stayed tight. ( knock on wood:p)

Gary

[James Phillips]

THe Bessey band clamps are the best you will find for this application. I suspect if you had gaps it is because the miters are not perfect. Did youcut them with a Miter gauge on your table saw or a miter saw? IMHO the table saw with a GOOD miter gauge is the better route. Also did you use a stop block to control length? If the length is off that is just as severe as the angle being off

[Mike Duffy]

You might want to try trimming them using a shooting board and a hand plane.
More information:
http://www.cornishworkshop.co.uk/shootingboards.html

or

http://www.whitemountdesign.com/ShootingBoard.htm

[Dan Barr]

yup,

what they said. once you get your tools dead-on...

Glue up is still annoying for me on miters. sometimes, i just hold the pieces by hand for about 10 minutes until the glue sets (assuming a PVA glue such as titebond)

then once i get the two halves set, i wait the thrity minutes and put the two halves together.

I usually reinforce with spline joints as well.

v/r

dan

[Mike Goetzke]

Clamps might help but I think the real key is to build yourself a 45 deg. miter sled for the TS and you won't believe how tight the miters will be.


Mike

[George Bregar]

Clamps might help but I think the real key is to build yourself a 45 deg. miter sled for the TS and you won't believe how tight the miters will be.


Mike +1. Best way other than special miter slicers.

[Sean Troy]

Clamps might help but I think the real key is to build yourself a 45 deg. miter sled for the TS and you won't believe how tight the miters will be.


Mike

Does anyone have plans for a miter sled? Thats one of the things on my short list. Thanks, Sean

[Jim Becker]

Miter sled is the best way to get complimentary angles...you cut each side on the opposite side of the blade to insure that you have a true 90º corner in the end.

[Todd Jensen]

Maestro clamps.

[Ron Kanter]

I have had success using masking tape to hold the joint together. Inexpensive (cheap), very adaptable, and doesn't require more space on the clamp cart.

Lay the two piece on the tape with the miter joint tips just touching and the 45 degree anles facing up. Close the joint with the tape now wrapping the outside corner.

____________\ /___________ 2 mitered pieces
_________________________ tape

If you do this with all four sides and joints strung together you have a stable package while the glue dries.

I was thinking about starting a thread on the best miter/corner clamps, but I'll let that wait for another day.

Ron

[Thom Sturgill]

http://www.woodmagazine.com/wood/story.jsp?storyid=/templatedata/wood/story/data/tablemiter.xml


Woodmagazine has a how-to article on making your own miter sled. this is one of my next projects.

[glenn bradley]

Making sure your miter dry fit is 90% of the battle. If they fit without needing to be squeezed into submission, very little pressure is required to hold them till the glue dries and it is easier to keep them square. Another vote for web-clamp with corner blocks.

[Fred Voorhees]

I am just finishing up making some picture frames and I have had no problem with the miters after using an aftermarket miter guage. I use the Incra 2000 and love it. It has always produced some nice joints for me. I have an extended miter fabbing fence that I attach to my guage and I use a 45 degree stop block to insure consistent length miters. For glue up, I also use the Bessey band clamp with the plastic corners for aligning each at 90 degrees. All has gone very well with this system. Oh yeah, I also always go with a dry fit to check everything first.

[Jason Morgan]

The project is hanging on the wall right now...mocking me every time I pass through our front door. I think that before the mocking gets too much louder Ill give the miter sled a try.

Thanks again.

[Nissim Avrahami]

Hi Jason

For a frame to be square and the angles tight....
*Every 2 opposite boards must be exactly at the same length
*The miters must be exactly 45° or, the sum of two angles must be 90°
*The miter itself must be cut vertically at 90°

To overcome small deviations, the best is to cut the miters on a table saw with a sled.

Use the Left/Right method and instead of putting the stop 4' behind, put the stop at the front.

I think that you will see the method on the next issue of WOOD Magazine but in the mean time have a look at my very first post on SMC...
http://www.sawmillcreek.org/showthread.php?t=36590

Regards
niki

[Dan Henry]

After all of the good ideas before this and you still have a crack and you are using raw wood, save the sanding dust and use it with thin CA glue to fill the crack, the dust will take stain and finsh and the cracks will disappear.

Put the CA glue in the crack, rub in the dust, more glue and rub in more dust as the glue drys, you get on your fingers just don't stick them together. It is a good idea to buy some debonder when you buy CA glue. The CA glue is available at stores that sell wood turning supplies.


Dan

[Robert Mahon]

If the part I want to miter is less than 2" thick, I set the TS angle to 45 degrees with a Wixey. If it's greater than 2", I use an Incra miter gauge. Both work wonderfully.

I suppose I should try a sled but so far, I haven't needed it.

I only use my compound miter saw for rough work.

[Ray Knight]

I used to do a lot of photography and use a lot of prestained frames. A high end framer clued me in on a trade secret for prestained frames. A little bitty gap will show at the cut mitered corner with the light raw wood against the dark prestained/finished frame. He keeps a selection of colored magic markers, and darkens the 1/8 edge that might show if the joint isn't perfect. Really makes a difference. Ray Knight

[Gary Keedwell]

I have been getting perfect miters with my Dubby sled for 15 years.
Gary

[Earl Reid]

.I also use my Dubby to get perfect angles , first time, every time. I use the tiny biscuits,glue and spring clips
on picture frames.
Earl

[Chris Padilla]

Bessey band clamp and small biscuits are what I like to use. Of course, and it has been stated several times, cutting the miters correctly is #1.

http://www.sawmillcreek.org/showthread.php?t=42603 Here is a very simple little mirror/frame I threw together over a few days.

[Eric Mims]

here's what I do to make absolutely perfect miters:

step 1: cut miters on radial arm saw, table saw, etc to rough length.

step 2: use miter trimmer (similar to http://www.grizzly.com/products/Miter-Trimmer/G1690) to trim the miter to perfect 45 degrees. Also check overall length of each piece and slice off until it is perfect with opposite side.

step 3: after dry fitting, slap some glue on and use a Merle band clamp
(http://www.mlcswoodworking.com/orderstatus/html/smarthtml/pages/merlclmp.html)

step 4: use my RAS blade turned sideways to cut deep groove out of each corner, then glue in 1/8" thick wedges (grain perpendicular to miter). then trim flush.

step 5: admire your perfect frame.

[Mike Jory]

Jason;
Of course I need to make sure I cut them right. I've tried a miter vise, and for most square and miter glue ups I use the Bessey band clamp. I recently tried this from Woodworker's Supply. I just did a pair of nested table tops and I think they came out better. The clamp puts even pressure all around, and keeps the unit square.
I figured, not to expensive, so I tried it.
Good Luck, Mike

[Jules Dominguez]

Jason, I have one of the clamps Mike shows, and it works very well. My first impression of it when I bought it was that it's too flimsy to do a good job, but it works very well. I've had mine for quite a few years.

[Mike Duffy]

Does anyone have plans for a miter sled? Thats one of the things on my short list. Thanks, Sean

Sean, if you buy an Incra miter slider, it comes with a detailed set of plans. (You'll need TWO sliders to build the sled.) Here's a link.

http://www.woodcraft.com/family.aspx?familyid=3178

I built one and rarely have to use my my shooting boards.

[Sean Troy]

Sean, if you buy an Incra miter slider, it comes with a detailed set of plans. (You'll need TWO sliders to build the sled.) Here's a link.

http://www.woodcraft.com/family.aspx?familyid=3178

I built one and rarely have to use my my shooting boards.

Thank you for the info. Sean

[Paul Johnstone]

I love spending other people's money, so I will second the nomination for a miter trimmer. I believe Rockler and Woodcraft also carry them.
Sure, it's about $100 (I can't remember exactly), but it does an excellent job.

Mine has 3 stops (45 on each side, and 90 degrees).

It also comes in handy because now you can use a bandsaw to crosscut and then use the trimmer to bring to a true 90.

I will also add that a miter trimmer is great for long pieces of trim, which might be a little difficult to handle on a tablesaw sled. If you are putting trim around doorways/windows, it will basically "pay for itself" :)

I use it a lot more than I thought I would.. If you can swing the cost, I highly recommend it. Also, keep an eye out for used ones. They pop up from time to time.

[Ron Kanter]

Amazon has the 18" sliders at a good price and you can buy 4 for 3 - a 25% savings.
Ron

[Bruce Benjamin]

I love spending other people's money, so I will second the nomination for a miter trimmer. I believe Rockler and Woodcraft also carry them.
Sure, it's about $100 (I can't remember exactly), but it does an excellent job.

Mine has 3 stops (45 on each side, and 90 degrees).

It also comes in handy because now you can use a bandsaw to crosscut and then use the trimmer to bring to a true 90.

I will also add that a miter trimmer is great for long pieces of trim, which might be a little difficult to handle on a tablesaw sled. If you are putting trim around doorways/windows, it will basically "pay for itself" :)

I use it a lot more than I thought I would.. If you can swing the cost, I highly recommend it. Also, keep an eye out for used ones. They pop up from time to time.

I've never used one of these miter trimmers but they look pretty slick. But how long can you expect the blades to stay sharp? I realize that the type of wood being trimmed will effect this. It sure does look like a very convenient way to sneak up on the exact length needed.

I have the Incra 1000SE miter gauge along with the Incra sled and, while I've only used it a few times the 45's I've made have been perfect right out of the box. The only issue I have is what you mentioned and that is that with longer pieces can be difficult to handle on the TS. But overall, I'm really impressed with the accuracy of the Incra gauge.

The Incra is miles beyond the Jointech Smart Miter I bought a few years ago. That was not only the worst tool I've ever bought but the worst customer service I've ever received. If anyone wants the long, detailed version of the story PM me and I'll send you a link to the review I did. I did manage to salvage part of the Jointech sled by removing the fence and adapting it to my Incra 1000SE gauge. After using both I've decided that the Jointech fence is a little easier to use than the Incra fence. It's the rest of the Jointech sled and the way it holds the fence that is so disappointing. The rest of the sled hangs on my wall to remind me to never again buy another Jointech product.:(

Bruce

[Chris Friesen]

*Every 2 opposite boards must be exactly at the same length
*The miters must be exactly 45° or, the sum of two angles must be 90°
*The miter itself must be cut vertically at 90°

Actually, that last bit isn't true. If you use a miter sled and cut the matching pieces on either side of the blade then it doesn't matter if the blade isn't perfectly vertical...the two pieces will be cut with matching complimentary angles.

Because of this, as long as the 90° corner on the miter sled is accurate, you can be slighly inaccurate in two different ways and still end up with tight joints.

[Jesse Cloud]

If you are too busy or too lazy (like me) to build your own miter sled, Rockler has this guy for $20

http://www.rockler.com/product.cfm?page=18030&filter=miter%20sled

It uses the right/left complementary angle theory, so the miters come out fitting great.

The slider has two screws to adjust to remove any slack. Easy to attach an auxiliary fence.

As for clamping, I built some miter clamps out of scrap. Cut a good miter in a pair of scrap pieces. Cut out a slot for attaching clamps across the miter. Stick some sandpaper on the inside to keep the workpiece from moving. Clamp each side to a miter clamp, then clamp the two clamps together - 3 small clamps for each joint.

Another tricky thing about clamping miters is to get the clamp(s) square in the middle of the joint. If the clamp is too high, you will get a good fit at the top and a poor fit at the bottom.

[Chris Padilla]

Actually, that last bit isn't true. If you use a miter sled and cut the matching pieces on either side of the blade then it doesn't matter if the blade isn't perfectly vertical...the two pieces will be cut with matching complimentary angles.

Because of this, as long as the 90° corner on the miter sled is accurate, you can be slighly inaccurate in two different ways and still end up with tight joints.

While this may be true, it is till good practice to ensure you cut at 90 degrees because it does matter on A LOT of other things! :)

[Lee Schierer]

Miter sled is the best way to get complimentary angles...you cut each side on the opposite side of the blade to insure that you have a true 90º corner in the end.
I agree, that's what I have and it works flawlessly everytime. It takes a bit of time to get it set right the first time to be close to 45 on one side, but you can still get good 90's with a 44 degree piece on one side and a 46 degree on the other.

If it doesn't fit well when dry, it won't get any better with glue and clamps. Forcing a poor joint closed for a miter will most likely lead to failure of the corner.

[Gary Keedwell]

I am a firm believer in good shop practices and for a good reason. When I tilt My saw blade I always try to calibrate it when I put it back to 90º If you don't do it right and you forget, a day or two down the road you might really need to have that true square cut and waste alot of time and wood because it is not cutting a perfect 90º. DAMHIKT:rolleyes:
Gary

[Terry Sparks]

All the advise everyone has given you is very good, but if you want the sleds and miter gages to work properly, you first need to check and make sure your saw table is perfectly square to your saw blade. With out this, the sleds and gages will only bring you right back to the same problem you have now, loose miters.

[Will Blick]

I will add a few issues....

the rockler product IMO is not a true miter sled and has some shortcomings. I see two potential problems with this approach.


1) If you cut both pieces of a miter on the same side of the blade, you are loosing the benefit of the bevel errors canceling each other out - which is why a true miter is more fail-safe. A simple solution would be, set the bevel .5 deg. away from the visible surface, so you are assured contact at the visible surfaces.... as if you have a slight bevel error in the opposite direction, you will surely see a gap, even though you may have perfect 45's, or, perfect sum of 90 deg.


2) With a miter sled, you always have tear out protection on the final part of the cut, which is where its most vulnerable. To have the same tear out protection on the Rockler, you must always use a backing board, and everytime you change pieces, you must move the backing board over further. There is no strong support between the backing board and the molding, as there is a gap between the Rockler product and the blade. If working with expensive moldings, this may be a consideration.


I am not knocking the Rockler product, for its price, its a nice, fast n easy miter cutter. If you have a slight favorable bevel (as in #1 above) to overcome the lack of compensating bevel errors, it will be effective.

Overall, there is 3 keys to perfect miters....

1) Perfect 45's, or next best, perfect sum of 90, which is what a true miter sled provides. (assuming you sled has a true 90)

2) Flat, or slightly favored bevels. Again, a miter sled automatically self corrects slight blade bevel errors.

3) Exactly equal piece lengths...this is often overlooked, and quite often the cause of gaps in miters, as we often focus too hard on the joint itself. Regardless of the miter cut method, this can be solved by cutting top/bottom together before moving your stops, then cutting L/R sides without moving the stops........or when possible, cut'em in pairs!

[Nissim Avrahami]

Actually, that last bit isn't true. If you use a miter sled and cut the matching pieces on either side of the blade then it doesn't matter if the blade isn't perfectly vertical...the two pieces will be cut with matching complimentary angles.

Because of this, as long as the 90° corner on the miter sled is accurate, you can be slighly inaccurate in two different ways and still end up with tight joints.
You are correct Chris

What I meant in the "conditions" is the optimal ones of course (that never happens)...

That's the reason that I'm cutting at the Left/Right method that overcomes small deviations from 45° of the miter and 90° of the blade

Regards
niki