How Do I Cut Perfect Mitres 22.5 Degrees

[In The Trenches]

I'm making a table top about 34"X22" out of two pieces of MDF light laminated together. It's going to be a bistro table 38-42" tall. I've done a

2" corner cut on all four corners so nobody breaks a rib when they accidentally walk into the thing. I'm using 3/4"X 2-3/4" cherry as an edging border and then I'm going to laminate the top with a nice bamboo patterned Formica over the edging and chamfer it back once the top dries to expose the cherry. My problem is, how do I cut the 1X3 cherry to perfect 22.5 degrees? What's the secret? I have a Delta QT-10 table saw and I set it to "around" 22.5 but invariably I get 22.1 or 22.7, my mitres are too opened or too closed! I need some fine tuning here. Any advice? Also while I'm here is it OK to use contact cement for the laminate glue if I'm planning on chamfering the edge or can I use yellow carpenter's glue? Thx.

[HomeBrewer]

could you do the edge on a router table?

[Doug Miller]

Get one of these:

it once with an accurate square (Incra sells those, too: ), and make dead-on accurate cuts at almost any angle you want.

-- Regards, Doug Miller (alphageek-at-milmac-dot-com)

For a copy of my TrollFilter for NewsProxy/Nfilter, send email to autoresponder at filterinfo-at-milmac-dot-com You must use your REAL email address to get a response.

[In The Trenches]

I had planned on using the router with a flush bit to square the edges prior to glueing the laminate. Also a chamfer bit with bearing to bevel the edge. My problem is with cutting the mitres. I'm cutting the edge pieces a bit proud and sanding them to make them fit. Seems to be working. Not perfect, but then what is.

[Swingman]

It's not necessarily a perfect 22.5 degrees you want, but a perfect 90 degree angle of the joint. This can be made up of say, a 22.7 and 22.3 degree angle.

IOW, you want to the two matching parts to add up to 90 degrees, whether they are precisely 22.5 degrees or not.

You can get this with a jig that insures you cut complementary angles for the matching parts. With a well made jig, and by cutting the two mating angles on opposite sides of the jig, you stand a better chance of cutting complementary angles for your desired 90 degrees miter joints.

These type jigs work well as long as the width of your frame member are not excessive and your two angles are very close to being equal, otherwise you may get some visible error in the length of one of the joints faces ... but that is rarely a problem.

One of the easiest ways to do that is on a table saw miter sled like the one on my website (Jigs and Fixtures page). You can also use a shooting board jig and a plane; or a jig on a stationary disc sander to accomplish the same thing.

The factory edge corner from a sheet of plywood is generally sufficient as the basis of the jig.

As in all cases with miter joints, you need to insure that opposite sides of your frames are precisely the same length.

[Swingman]

Please pardon for the typo ... that was supposed to be 44.7 and 45.3. for a

90 degree miter.

[Swingman]

Talking to myself again ... compliments of that first cup of coffee.

I forgot to mention to the OP that the idea/philosophy behind cutting a "perfect" 90 degree miter joint with the described jig(s) will also work for his desired 45 degree angle cut for the corners of his table top.

It is the concept that is important, not the desired angle of cut.

I recently, in the last year, made a jig using the stationary disc sander to cut 45 degree joints for a similar table top (walnut coffee table in my projects journal below for the results).

[Frank K.]

MDF light

tall. I've done a

when they

cherry as an edging

bamboo patterned

dries to expose the

perfect 22.5 degrees?

set it to "around"

opened or too

while I'm here is it

planning on chamfering

And put

119-036 in the rapid order box. I just ordered two items from Woodworker's Supply on Sunday and they will be here (in Delaware) tomorrow.

[Edwin Pawlowski]

You don't. You cut them at 67.5 degrees. :0 :) (extra emoticon added "just in case") Ed

[Swingman]

I started to say 54 degrees ... but ... went for a run this morning in the dark and twisted my ankle, got back, poured a cup of coffee and found out there was no cream or sugar in the house, sat down at the computer and tried to answer the OP's question and never could get on the right track, gave up and went to the dentist for a root canal that was subsequently aborted, leaving me temporarily with a hollow tooth, soon to be extracted, and one hell of a toothache that right now seems more permanent than the tooth.

... so I elected to NOT push my luck in the shop today.

[The Davenports]

Oh, my god...ever get the feeling that you should have just stayed in bed today?

Likely a REAL good thing that you avoided the shop today.

Hope your tomorrow goes better.

Mike

[John]

Get theh miter gauge setup jigs from Duginski

John

[Bigpole]

Make sure the wood is not moving when you cut it. I don't think you can hold the wood using only your hands. You need some king of clamping or stop block. Ted

[Jay A.]

I would start by tuning up your miter saw at 90 degrees. Make a cut on the widest board that the saw will crosscut, flip it over and see how close the second cut is to the first then adjust. You should have a cut off piece that is a constant width and thin as paper. Swing the saw to 22.5 and you will be good. Jay A.

[DerbyDad03]

I would start by realizing that the original thread is from 2004.