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crown molding

#1
03-07-04, 05:57 PM
Member
Join Date: Jul 2003
Posts: 54
crown molding

hello,

i am installing oak crown molding in my living room. for the 90 degree corners i have been putting the crown molding upside down in my miter saw, cutting it a 45 degrees, then coping the revealed profile. works fairly well. i have two corners that are 135 degrees. what do i here?

#2
03-07-04, 09:12 PM
Member
Join Date: Dec 2003
Location: Bay Area, CA
Posts: 1,178
This will be trickier because you need 67.5 degree miters. If you can make a jig to hold your crown perpendicular to the miter saw guide, set the angle to 22.5 degrees.

#3
03-07-04, 10:25 PM
Furniture Bldr
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Take 135-90 = 45 which half of that would be 22.5 as dave said.

Any degree angle greater than a 90 deg angle needs to be subtracted by 90 degs and divided by 2

When it's an acute angle like you have, then you need to make a jig like dave told you. When you have an obtuse angle, then you can do the math just like it is in the first line.

Arent those angles fun Dave?

#4
03-08-04, 06:47 AM
Member
Join Date: Dec 2003
Location: Bay Area, CA
Posts: 1,178
Sure am glad I paid attention in Geometry.

#5
03-08-04, 08:51 AM
Member
Join Date: Jul 2003
Posts: 54
when you say jig, do you mean something to hold the crown at an angle against the fence (the fence being the wall and the miter saw table being the ceiling)? cause i do have one of these. so i just use this and cut at 22.5 instead of 45?

#6
03-08-04, 10:13 AM
Member
Join Date: Dec 2003
Location: Bay Area, CA
Posts: 1,178
Not exactly.

I'm talking about something that is a bit risky because you're cutting the crown perpendicular to the "normal" way.

You need a 67.5 degree miter to make that 135 degree angle. Your miter saw probably can't cut miters much beyond 45 degrees. (Mine will go to about 47 degrees).

I'm suggesting that you make a jig that will allow you to lay the crown perpendicular to the built-in fence and cut the miter at 22.5 degrees.

This gets a bit risky since;

1. The jig must be exactly 90 degrees to the built-in fence.

2. The jig must be stout enough to hold the crown perfectly in place without flexing (and throwing off the angle).

3. You have to be very careful how you hold the crown in the jig so you don't cut off any fingers you want to keep.

I've only done this a couple of times and I really don't like doing it. You might be better off finding a local shop that can make these cuts for you.

Good Luck

#7
03-08-04, 04:21 PM
Furniture Bldr
Visiting Guest
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Once again, Dave is on the money.

The jig/cut you need to make can and is quite dangerous. It would be very easy to cut your fingers off.

Maybe I can make it a bit easier for you to understand.

-------- l -------
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The horizontal lines with the I in the middle represent the fence of the saw and the blade.

The single dashed lines represent the way the crown has to sit in relation to the fence. "90 Degs to the fence"

You need to make a jig to hold the crown out this way and on the angle of cutting normal crown. Then turn your blade to either side to make the angled cut. The jig will either sit on the right or left hand side of the blade, depending upon whether its a right or a left cut.

#8
03-09-04, 08:39 PM
Member
Join Date: Jul 2003
Posts: 54
ok i think i understand now. so once i make this cut i cope the profile like i have been doing?

#9
03-16-04, 02:23 PM
Detroit Guy
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A 135 is an obtuse angle. Not an acute angle.

#10
03-17-04, 08:13 PM
Tom_J
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Detroit,

I was going to mention that, too, but Mike was on a roll...

(He's good for other stuff, though, so we let him slide. )

Tom

#11
03-18-04, 03:49 PM
Furniture Bldr
Visiting Guest
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Hey, I may not be very Ed-u-mah-ca-ted with mathamatical terms, but I do know how to make it work