Gluing miters without slippage

[Curtis Niedermier]

Anyone have photos or simple tips for how to glue miters without them slipping?

I recently built a really basic small shelf for above my workbench, and I wrapped the front edge and both ends with narrow boards to create a lip so that nothing would fall off the shelf (I keep coffee mugs full of dividers, pencils, nail sets, etc. on it). When I made it, I carefully cut and fit each piece for a perfect fit.... then they slipped in the clamps....grrr.

Coming soon, I'm going to be mitering a couple face frames and making a box with all four sides mitered together. I don't want slippage.

Please, help me prevent slippage.

[Garrett Ellis]

do this: http://www.thomasjmacdonald.com/rough-cut-woodworking/media/video.php?vid=5322cbf87

i've tried several ways including applying a thin layer of glue to form a skin to help prevent slippage, big band clamp, other clamps.... the glued on clamp blocks work by far the best. you can get a super tight joint and adjust it as you tighten the clamp. then plane off the block after it has cured. another perk is that you can glue 1 joint at a time if you want, instead of trying to get every joint lined up perfectly while tightening multiple clamps.

and since you asked this in the neanderthal forum, i will assume you are using a shooting board to get perfect 45 degree angles on your pieces before even attempting to glue.

[steven c newman]

Two ways to prevent a slide happening in a mitre joint:

Add a strip of tape on the "backside" of the joint, going across the glue-up 90 degrees to the glue line. Wide as you want. Can be scraped back off later

2) Take a small brad, drive the point into one side of the joint. Clip the brad off close but not flush. Leave enough of a "point" to stick into the other half of the joint. Acts like a "pinned joint". Doesn't take all that much to work.

[Joe A Faulkner]

The old adage, you can never have too many clamps comes to mind. I've used a combination of things, including 90 degree corner clamps like these

http://www.amazon.com/Pro-Grade-59162-Corner-Clamp-90-Degree/dp/B00FJ02K0O/ref=sr_1_3?ie=UTF8&qid=1453335054&sr=8-3&keywords=90+degree+clamps

coupled with c clamps, f clamps, bar clamps, quick grip clamps. This means often times that I need to use a piece of scrap between jaws of the clamp and the finish piece to prevent maring. If these "pads" are over or close to a glue line I might cover them in packing tape or use a piece of wax paper. Sometimes I'm quite amused by the mess of clamps that can be used on what appear to be "small" projects.

[Mike Henderson]

I put biscuits in the miters. You can see how I cut the slots for the miters on my router table here (http://www.mikes-woodwork.com/RectangularTray6.htm) (about half way down the page).

Mike

[Stanley Covington]

Curtis:

I agree with Mike: Biscuits are the bee's knees. Splines work even better, but are more work. Dowels are OK. Even a couple of brads help.

The best method is to use the Bessey Angle Clamp. Very fast and foolproof. Nothing I know of beats them. No downside other than price.

http://www.besseytools.com/en/product_details.php?ASIMOID=000000020003e008000400 23&ASIMOID_SC=000000020003eb7d00020023&ASIMOID_MC=

[Keith Mathewson]

312 gram strength hot hide glue. You can hold the piece in place with your fingers until it tacks and it tacks very quickly.

[Reinis Kanders]

Add a dot of superglue, then you can just hold it for 30s or so.

[Garrett Ellis]

I'm surprised at the miter clamp recommendations. Those things have proved useless in my experience. The force applied is not in the direction needed. And what do you do if you have a miter other than 90 degrees?

[Niels Cosman]

you can always glue on 45 degree glue blocks to the corners pieces, this will allow to you to clamp normal to the glue surface. The trade off is that you will then you'll have to remove he blocks after the glue up.
You could also add splines.

[Charles Wiggins]

The old adage, you can never have too many clamps comes to mind. I've used a combination of things, including 90 degree corner clamps like these

http://www.amazon.com/Pro-Grade-59162-Corner-Clamp-90-Degree/dp/B00FJ02K0O/ref=sr_1_3?ie=UTF8&qid=1453335054&sr=8-3&keywords=90+degree+clamps

coupled with c clamps, f clamps, bar clamps, quick grip clamps. This means often times that I need to use a piece of scrap between jaws of the clamp and the finish piece to prevent maring. If these "pads" are over or close to a glue line I might cover them in packing tape or use a piece of wax paper. Sometimes I'm quite amused by the mess of clamps that can be used on what appear to be "small" projects.

Curtis,

I've used a 90° clamps before and they work pretty well. I've currently got a Bessey (http://www.amazon.com/Bessey-WS-3-Angle-Clamp/dp/B000022454). I just use it to hold while I put brads or screws in the joint, then I move on to the next one.

If you don't want to use fasteners, and the piece will need to sit in the clamps while the glue dries, I would either invest in something like Rockler's Clamp-it system (expensive) OR make a bunch of these (http://www.woodmagazine.com/woodworking-plans/clamping/right-angle-jig-gives-you-a-corner-on-clamping-tasks/) or these (http://www.woodworkerz.com/corner-clamps-for-better-miters/).

Hope this helps.

[Barry Dima]

Here's a pic of a jig from a page on Derek Cohen's website (http://www.inthewoodshop.com/Furniture/BuildingaMitredPencilBoxwithaShootingBoard.html):

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(Derek attributes the idea to Andrew Crawford.)

The joint can still slip, but with the jig, you'd have plenty of positive stops to feel against while making sure the joint is and stays where you want it to and for the clamps to act against.

[Nicholas Lingg]

http://www.woodcraft.com/product/153789/blokkz-universal-clamping-blocks.aspx

Watch Video

[Patrick Chase]

Curtis:

I agree with Mike: Biscuits are the bee's knees. Splines work even better, but are more work. Dowels are OK. Even a couple of brads help.

The best method is to use the Bessey Angle Clamp. Very fast and foolproof. Nothing I know of beats them. No downside other than price.

http://www.besseytools.com/en/product_details.php?ASIMOID=000000020003e008000400 23&ASIMOID_SC=000000020003eb7d00020023&ASIMOID_MC=

I use splines, biscuits, and/or the Bessey angle clamp. They all work very nicely. I really like the look of splines.

[bridger berdel]

I use a few pieces of masking tape on the outside of the joint, pulled tight.

[Denny Tudor]

I alway make sure to precoat the end grain as it sucks up glue quickly . That means you really don't have as much in the joint as you think. The I use blue painters tape on both side of joint when laid flat. When folded over to the 90 degree joint, the tape really tightens up to make a very strong clamp .

[Patrick Chase]

I alway make sure to precoat the end grain as it sucks up glue quickly . That means you really don't have as much in the joint as you think. The I use blue painters tape on both side of joint when laid flat. When folded over to the 90 degree joint, the tape really tightens up to make a very strong clamp .

Do you precoat as part of the final glue-up process, or do you actually size the end grain and let it [partially] dry? If the latter how much do you dilute the glue when you mix your sizing?

[Denny Tudor]

Do you precoat as part of the final glue-up process, or do you actually size the end grain and let it [partially] dry? If the latter how much do you dilute the glue when you mix your sizing?

I don't dilute it- just a little dab on the joint, rub the two pieces together and then let em set apart a minute or two . You will get a good even surfice coat that way. Then I apply more glue to one side only , a little more rubbing around and tape clamp up. Then they set a long time. I do a lot of small boxes. Check cross measurements and outsides with a try square. They must really be cut right on or they will rack one way or the other. Seems to work for me. I don't like clamps as the apply to much pressure and knock very thing out if sack.

[Bill White]

I knew a fellow who would add just a touch of sand in several places on the surfaces.

Bill

[Doug Hepler]

Thanks to Nick Lingg for the tip about blocks. This is a refinement of an old idea. The sales video showed me lots of good ideas. However, at that price I will make my own out of wood. I think square blocks might actually work better for miter joints.

I use Denny's idea and it works very well. Very uncomplicated. You need good masking tape, though.

If you don't have sand, try a bit of salt in the joint. I hear it works just as well.

You can buy band clamps with corner blocks meant for making picture frames.

I find that corner clamps (screen door clamps) are too much trouble but occasionally I need to use them.

[Patrick Chase]

I don't dilute it- just a little dab on the joint, rub the two pieces together and then let em set apart a minute or two . You will get a good even surfice coat that way. Then I apply more glue to one side only , a little more rubbing around and tape clamp up. Then they set a long time. I do a lot of small boxes. Check cross measurements and outsides with a try square. They must really be cut right on or they will rack one way or the other. Seems to work for me. I don't like clamps as the apply to much pressure and knock very thing out if sack.

Thanks - that's sort of what I thought from the way you worded your first post.

The other option is to size the end grain using diluted glue as sizing (I use 1:3 or 1:4), and actually let it dry. That's what I usually do, but I've never compared it to a double-application without drying as you describe...