pattern and cope cutting problem

dovetail3 | Posted in Joinery on November 16, 2002 10:57am

When cope cutting the ends of my maple boards I used a fence and 1/4″ ply as a backer board. I had tear out problems in spite of my preparation. Is there a better way to prevent tearout? Also, Is there a better choice than wood filler to conceal the tearout after assembly? Thanks

Replies

JPGrout | Nov 17, 2002 07:12am | #1
Do you cope the ends first, or cut the sticking and then cope the ends. In my experience if you cope the ends first then cut sticking it usually cleans up the tearout. I also cut rails about 1/8" wider than finish size so I can cut off in case of tearout on the exterior edge of the door. Joe

dovetail3 | Nov 17, 2002 08:46pm | #8
Joe: This is the first time I've tried this and I was advised to cut the patterns first then the copes. I wish I had this terriffic advice before I completed the work. Next time should be great. I guess I'll have to use some wood fill at the corners. I'm using maple. Any suggestions on what is best to use for a filler?

Thanks, Ken

charlesm | Nov 17, 2002 07:25am | #2
The best solution I know is to use material for the stiles and rails that is at least 2X the width plus 1/8". The object is to cope the rail ends for both rails on one piece of wood, then shape the stile cuts, then rip to finish width. This method erases the tearout and insures that both rails and both stiles are the same length so the door is square.

If it is necessary to use the method you are using try 3/4" thick material for the backer board. It will give better support.

Charles M

Freud, Inc.

silver77 | Nov 17, 2002 09:07am | #3
I saw your other post regarding vertical/horizontal router bits and am very impressed withyour knowledge and short to the point answers. I wish more manufacturers had the sense to get involved. Gives me a good reason to stick with Freud.

Regarding the cope cut,I have never considered 2 outta one, then rip. It doesn't help the tear out problem unless you're jointing the ragged edge or backing with 3/4" 12 " x 12" square.

cheers,

silver

charlesm | Nov 17, 2002 05:04pm | #4
Thanks, Silver. I use the 2 out of 1 method almost exclusively and find that if I use 6" wide stock (or wider) that I can ride the fence without a miter gauge and any tearout on the cope is erased by the profile cut so I don't need a backer board and I don't need to joint the edge afterwards.

Charles M

Freud, Inc.

silver77 | Nov 17, 2002 07:40pm | #5
I enjoy learning something new that never occured to me...opens my mind to other areas that could be improved by changing technique.

Thanks, Charles

silver
dovetail3 | Nov 17, 2002 08:40pm | #7
Charles: Forgive my ignorance. I think the answer to my previous question resides on this post. If I'm correct you do the cope cuts first then remove any tearout with the pattern cut. However, it seems to me if you use material of a greater width than necessary and trim to size there will be no tearout to deal with. Also, Isn't it easier to match the cope cut to the pattern?

Thanks Again. This is great!

charlesm | Nov 17, 2002 09:15pm | #10
Cope and stick is like any edge treatment operation in that you should cut end grain first, then the long grain. The pattern cut does erase the tearout produced on the end grain. It is easier to match the cope to the pattern because you want to get the reveal right on the profile, but a sample piece of stick cut can accomplish that. For 3" wide stiles and rails you should use stock that is at least 6-1/8" wide (3"+3"+1/8"). The extra 1/8" is for the kerf of the rip blade.

The reason you can't accomplish the same thing with four separate frame pieces is that the pattern cut will only erase the tearout on one end of the rails. The other end will be running the wrong direction and the tearout will be on the outside of the frame when assembled.

Charles M

Freud, Inc.
dovetail3 | Nov 17, 2002 11:50pm | #11
Charles: Thanks again. I appreciate the great advice. If I understand correctly. It is still O.K. to make cut the pattern cuts first, then, with test pieces, match the cope to the pattern. If I double the width of the rails then rip some material from both sides I should end up with perfect cope ends with any tearout having been removed. Am I correct? And if it you don't mind, please let me know if there are any precautions necessary when routing the raised panels. I'm about to do so for the first time

Ken
charlesm | Nov 18, 2002 02:56am | #12
I'm not sure you have it exactly right. Don't do the pattern cuts first. Make a sample cut with the pattern cutter and use it to set the cope bit. Then make the cope cuts. Next do the actual pattern cuts. Lastly rip to width.

Charles M

Freud, Inc.
dovetail3 | Nov 18, 2002 03:17am | #13
Charles: I think I get it now. Once I've made the sample pattern cut I'll save the test piece to duplicate when I make the rest of the pattern cuts. Whew! lot of great info. I'm grateful and hopeful all goes well when I make the raised panels.

Thanks Again

Ken

dovetail3 | Nov 17, 2002 08:48pm | #9
Silver: I'm not sure I understand your suggestion that cutting oversize then trimming afterwards doesn't help solve the tearout problem. Could you please elaborate?

Thanks much!

Ken

dovetail3 | Nov 17, 2002 08:34pm | #6
Charles: Thanks much! I'm not sure I understand when you suggest 2X plus 1/8".

If the final measure I want is rail and stiles 3inches, what width should I start with?

Also, I was advised to cut the stiles (pattern bit) first, then the cope. Do you agree?

Ken

JPGrout | Nov 18, 2002 04:21am | #14
The advice that Charles MC gives is good. I have only one concern:

If for whatever reason the part you intend to shape is not foursquare at any point from the start to the last cut when you rip the parts in two one piece is apt to be tapered. That may be OK for an overlay door but an inset door will not fit properly in the opening.

Hence my suggestion of over sizing the parts by a certian amount( I usually go 1/8-1/4" in widthon all the parts and 1-2" in length on the stiles). Then you can shape the parts,cope first then sticking takes off any tear out from the cope cut. Prior to glue up I rip the stiles to the proper width so the door has two parallel sides. After you take the door out of the clamps you can then go back to the saw and crosscut the door to the proper length. You will have a square door this way and can accuratly fit over or into any opening.

This process has evolved over time into the most consistant way to build doors from 6" x 12" cabinet doors to entry and interior doors as large as 4'x 12'

As to the issue of tearout the only thing I may suggest is to cut off the blown out sticking and glue on a piece a little wider and longer than the sticking. Then carefully cut the piece to the original length and do the following:

Cut a backing stick and attach it to your crosscut device (make it at least as tall as the thickness of the rail stock and at least 12" long) and butt it up against the shaper fence (you do use the fence to set your rail cut lengths so they are all the same right) and set the stock up against the backer. This should prevent the ends from blowing out if you keep the part firmly against the backstop. Then re cut the sticking and you should be good to go.

I know it seems like a lot of work (it is) but you will be much happier with the end result by taking the high road on this one.

I also realize this is a lot of info to digest so feel free to post more questions I am happy to help Joe

Edited 11/17/2002 8:23:45 PM ET by JOEGROUT

dovetail3 | Nov 18, 2002 05:54am | #15
Joe: You're right. It is a lot to digest. I'm going to sleep on it and probably post again tomorrow. I'm grateful for all your imput and appreciate it

Ken