I have been trying for years to cut 45 miters and have them come out reasonabley square, gap free etc. I have yet to do this. I now have a base of a jewelery box that is out. I glued up long and short sections using hide glue. When we put the two glued up pieces into the clamps to see how they would fit up the joint came apart. I tried CA glue in hopes I could get them fitted and then cut a spline in the joints to hold them together. This stuff did not even start to hold. I stuck on my finger and that was it. So now what? I have no knowledge of how to glue these things together. Resawing them won’t work as I would have to cut everything else down too. The open end grain is full of glue. When I cut 45s I make sure they are of equal length and the miter guage is set at 45 using a 45 guage. I have a stop on the miter to ensure equal length and I still come out screwed up more times than not. It is to the point I cannot stand the frustration anymore and am thinking this is not for me.
Replies
Aw don't get down. Miters are one of those things that sound so easy until you start wanting to care about them. That table saw or chop saw or whatever you're cutting with doesn't have to be off much and by the time you go around a box, that little fraction of a degree on each cut adds up to time for Tylenol.
Lots of things out there for miters, and all I can say is try something you like and practice. If the table saw isn't doing it, check that for whether or not you're getting straight cuts. Jointers can set the fence at 45 and clean up a cut, just make sure you set it shallow and shave the same off of every board. I do that when mitering together the boxwork for fireplace mantles. It'll make a 5ft long joint kiss. You can try router bits at a 45, which should work if the edge is dead straight.
Then there's clamps - collins clamps and Ulmia clamps are both spring style and useful for holding small stuff. The Ulmias bite more, so leave marks that need filling. The Collins clamps are good for small stuff like baseboard returns, picture frames, etc. Then there's http://www.miterclamp.com - Jim Chestnuts miter clamps, mostly geared for trim guys, but they'll pull together a mitered casing in a hurry.
practice practice practice. It's not fun if you give up halfway there.
"If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man." - Mark Twain
Dear Jerry,
Cutting mitters as such in a TS with accuracy is difficult because the force of the cut is large compared to the work-piece supporting means and its tolerances. In a mitter gauge, you'd have to go rather slow, or even make two cuts, the second one being just a slight trim cut. You can try making a simple slade that rides agains the fence and is itself equipped with as sturdy as possible, and high fence-clamper that presents the piece very well-supported (unmovable) to the fence. You also need a good sharp cross-cut blade for more precision and less effort in the cut. The piece supported just by the hand does not contribute to an accurate cut. The firmer the support and clamping,. the more accurate the cut will be.
A chop-down saw, for instance, because they cut against the base (unmovable) do a very good job at cutting such mitters. That's because the saw force is down against an unmovable support. Even if it's ####slider chopper, it also beats the table saw because the work piece is resting against a fence. In a t.s., the work piece is moving as it slides agains a moving blade. So, in a t.s., all involved factors are moving (work piece and blade) tending to less accuracy, whereas on a chopper only one item (the blade) is moving.
So the issue can be resolved by addressing the support means. Make them as firm as possible.
Good luck.
-mbl-
We finally got the four pieces glued up. We had to use one of those strap clamps. The Bessy clamps just would not work due to the piece being too far out. It seams to me it is about 1/16 to 3/64 out. I am going to wait for the glue to dry and put the plywood bottom in and glue it so the miters hold. I read that hide glue would secure end grain. I have had it fail twice. Am I doing something wrong. The glue was clamped for 24 hrs and the piece not messed with for several days. I will try my DeWalt sliding miter saw next time. I see your point in that the piece would be held against the fence by the saw blade. I get so discouraged as I have little to no mechanical ability. I cannot read a plan. I have had people show me what needs to be done on the plan and it just does not register. If I see something done then the plan makes sence to me.
Thanks to all for the help.
JT
Jerry,
Instead of using the miter fence on the table saw, I made a fence out of a 90* plywood corner, mounted on a strip diagonally (45*). The strip slides in the groove used by the miter fence. I screwed and glued additional strips to the 90* edges that act as fences to support the moldings that I am mitering together. Using first one side, then the other, of the shopmade fence, I cut one side. then the other, of the miter joint. Since the fence is 90*, the two cuts add up to 90*. Check to be sure the blade is exactly square to the sawtable. I use a stopblock if the molding isn't too long, or clamp the piece to the fence. If holding the mold with just hand pressure, I make a cut to rough length, then "sneak up" on the final length with light trim cuts. If possible I attach each piece of molding to the case, rather than depending on the joint itself for structural strength. It may be easier to mortise and tenon a frame together, and then attach narrow molding to that, than try to miter four wide pieces together as a base frame. For picture frames, I usually assemble the frame all at once with a band clamp, then carefully saw across each corner (1)with dovetail saw for a veneer spline, or (2) on the table saw with a carriage that rides along the rip fence holding the frame with the corner down against the table.
For miters on things like box sides, or bracket feet, I cut to length with the sawblade at 45*, using the crosscut fence (miter fence set at 90*). Cut two pieces of scrap, and try them together to achieve a 90* fit. I have an auxillary (sp?) fence to screw to the rip fence. It presents the stock leaned over at 45* to the 90* blade (miter on the table) so I can run the mitered ends over the blade to rip a slot for a spline, centered in the width of the mitered end. I crosscut splines off the end of a piece of stock thicknessed to fit the sawkerf, and spline the joint at glueup.
Regards,
Ray
Ray-
Any chance you could post a picture of that jig you use? It sounds like something I've been thinking about trying.
Thanks
Dave,
Sorry, I don't have a digital camera yet. Which jig are you interested in? I'll be glad to try and describe it better.
Regards,
Ray
The jig you described in the first paragraph of your earlier post. It sounds like something I was thinking of making. Maybe I'll make mine and post some pics for you to look at. I would love to find a way to nail a miter without having to spend time dialing something in to get the right angle.
Dave,
Ok, here goes. Imagine a 45-45-90 triangle of 1/2" plywood. Mine is about 12" long on each of the two sides that form the 90*angle. The point of the 90* angle is tangential to the table saw's blade, actually it's been cut off a little by the blade. The plywood is guided past the blade by a 3/8"X3/4" strip that's attached to the underside of the plywood. The strip holds the plywood so that the two sides are at 45* to the blade, and fits into the miter guage slot in the table. In other words, the strip is parallel to the hypotenuse of the triangle. Try to get this as close as you can to being right, but if you do get off by a froghair, don't obsess, as any discrepancies are cancelled out rather than doubled, if you remember to cut each half of the miter on different sides of the fixture.
I've glued and screwed a 7/8" thick X1 1/2" tall fence to each of the two sides of the plywood. They are flush with the edge of the ply, so the supporting surface is a total of 2" tall. They also , I'm sure, help keep the plywood flat.
I don't doubt that a larger version of this thing would be good, but this was done years ago in a hurry, with a piece of scrap plywood, and I've never taken the time to do over, as it works just fine for me.
Be sure to use a "factory corner" for your 90*, if it ain't perfectly square, your joints won't be, either.
Be sure to stand to the side when using this thing; one of my carbide blades is bad about snatching an offcut once in a while and flinging it across the shop. It's like it creates a draft that sucks the piece into the blade.
Hope this helps,
Ray
If I am cutting a Mitered Square I Try to cut All four Pieces Stacked On Top Of Each Other Your dewalt slider Should cut pretty accurate If you want perfect miters you have to sand them to fit with a disk sander Hope This Helps
This seems real basic but nobody has mentioned it. You stated that you checked the blade with a gauge but did you try flipping the two ends and seeing if they come up at 90 deg, or cutting another peice to see if they are straight?
If the first cut doesn't result in a really true 90 deg corner (measured with a machinists square or something else precision), four of them will NEVER be square!
This is like the test for a table saw blade being verticle to a table. You make a cut in a board, flip one end see if there is a gap.
I say the above and I have yet to get miters I am proud of either! But I AM getting closer.
Michael
Jerry
Just a thought. If you're using a very fine toothed blade or you sand the mitre, you will sometimes burnish the end grain and the glue has difficulty hanging on to the slick surface.
I cut my mitres a tad long and shoot them with a low-angle plane on a home-made shooting board. I believe everyone has experienced your delima with mitres not mating in the beginning, so don't feel alone.
Regards...
sarge..jt
Proud member of the : "I Rocked With ToolDoc Club" .... :>)
Sarge;
Where do I find out how to make a shooting board?
Google for "shooting board" in quotes. There are links both to projects and to descriptions of the finished tool.
Jerry
I think Dunc has nailed it down. I built mine from a design in some mag. I have seen so many different designs (most are similar somewhat) I don't remember which one. It may have even been one of those "jigs and fixtures" editions.
As Dunc stated, many threads here have referenced them and a ton of different mags have printed plans. They are simple to build and effective if you got a good plane that has 90 degree sides and sole.
Good luck and always remember when you get frustrated, you aren't anywhere most of us have already been. I wish I had fast access to the info you can get here 30 years ago. You have a unique situation with todays rapid technology. Use it wisely and too your advantage.
Regards...
sarge..jtProud member of the : "I Rocked With ToolDoc Club" .... :>)
Lots of good suggestions about cutting the 45 degree miters. As noted, they look simple and are actually very hard to do. And the suggestions given seem great.
But some of the problem seems to be glue. A miter is largely end grain on both pieces. And glue does a terrible job with end grain. Which is why people use splines, biscuits, lock miters, and just about every other trick to get some side grain into the glue game.
And some of the problem seems to be clamping. If you take a plain miter, almost anything you do to clamp will let it slide out of alignment. Sometimes I cut a block of scrap, to put in the middle of the box or frame, just to keep the sides aligned for gluing. Or the biscuit, lock miter, spline solutions help here too.
Which is why I find it easier to build a table or chest of drawers than a !#@$@!#%! picture frame.
________________________
Charlie Plesums Austin, Texas
http://www.plesums.com/wood
Edited 3/31/2004 12:12 am ET by Charlie Plesums
I recently made a small cabinet for my in-laws. It was basically a mitered box. Well, I made a prototype out of some poplar I had laying around to check the design. I liked it, made a few minor design changes and made the real deal out of birch to match the vanity. It was a case of complete blind luck the first time, because the corners on the birch box were way out, though I used the same set-up on each. Lessons learned:
1) I use a table saw, so I made a sled, dedicated for the blade leaned over to 45 degrees.
2) the old trick of making a test cut and fitting the pieces together to check for a right angle isn't accurate enough. Make a test box - that way you've got four corners. Small errors add up quick for a box.
3) after the box is glued up and the clamps come off, use a hard round tool (like the shank of a screwdriver) to slightly burnish the corners. Small gaps get gone quick.
Jerry, you will cut perfect miters every time, this is an old carpenters trick. If the angle is 90* , theoretically both pieces will be 45*. Whatever saw you use , set the angle to 45 1/4 degrees. If you are using a mitersaw make sure the saw does not jump into the detent. If it does you may have to use a thin shim, like a playing card. If you are using a table saw, set to 45 1/4* and cut both miters like this. This will work for any mitered outside corner.The front of the molding or box side will touch, the inside theoretically will be open. You can't see any gaps though.
If you are using hot hide glue , just clean up the other glue best you can and reglue with hot hide glue.If the miter does not come out perfect but looks better , use 45 1/2*. Try this out on scrap, I guarantee this will work.
mike
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