THE PERFECT MITRE

Jason

CGF, Certified Grumble Framer
Joined
Dec 3, 2004
Posts
198
From
Iowa
Anyone have some helpful hints for a PERFECT miter. I am using the Phaedra System on a Dewalt 12" saw and a Fletcher 5600 v-nailer. Getting nice frames, but my miters are not 100%. The saw seems to be perfect and the nailer works great, what am I missing? Any thoughts would be appreciated. Thanks!
 

Sister

MGF, Master Grumble Framer
Joined
Apr 18, 2004
Posts
945
From
Alabama
Good question and I still don't have all the answers. I, too, have had this problem with the same equipment. Is the 100-tooth blade sharpened for the best cut? If so, read on. First, make sure the molding is held completely immobile when cutting. Second, let the saw run to the maximum speed (rpms or whatever) before beginning the cut. Third, lightly sand the mitre cuts before joining. My cuts and mitres have much improved but I wouldn't say perfect. Hopefully, we will get more helpful responses.
 

Mick11

CGF II, Certified Grumble Framer Level 2
Joined
Dec 5, 2004
Posts
211
From
East Yorkshire. UK
I have had some problems when the mouldings are not quite true. Particularly if the base is ever so slightly convex, or not square to the back.This allows the moulding to roll slightly when cutting or nailing.
Also check the angles on the saw and nailer with an accurate 45deg and 90deg set square
Hope this helps
Mick
-------------
The impossible I can do today,
Miracles take a little longer
 

treeves

CGF II, Certified Grumble Framer Level 2
Joined
Dec 15, 2004
Posts
218
From
SouthEast
Jason, Make sure the base is level,use a level or a long tru straight edge to make sure you have no gaps under your straight edge. If you place you cuts on a flat surface and mitre cuts are perfect, then you know the saw is ok, and then its on to the joiner. Make sure again that your joiner table is flat and level and your corner fits perfect into your V, if yours has automatic clamping device, it must clamp your corners so that their is no gaps, if ok, then clamp and ck corner to see if too much pressure is causing the corner to separate, and adjust if need be, if still not getting a good corner, then repost with your results.....and as Jerry said, you may have to tweak alot to get the corner perfect......
 

Warren Tucker

MGF, Master Grumble Framer
Joined
Jul 19, 2003
Posts
725
From
Wilmington, NC
Business
Frame Works / Frame Outlet
There are no "Perfect Miters"; the notion begs the question: perfect in relation to what? The back of the molding or the front; if the back, for what portion of its length? Frequently, the lip of a molding isn't perfectly parallel to the molding's back. What you want is the best miter you can get working with imperfect material and somewhat imperfect equipment. I honestly don't think a chop saw that you swing from right to left miters will give good results. Get two saws and lock each at as close to a perfect 45 degree as possible right and left and then never move them.

If you can't get good cuts from your present set- up, perhaps the easiest solution would be a good miter sander; nothing is going to produce a better miter than a sander. But as I mentioned, there are no perfect cuts; every corner has to be tweaked to an extent. If before you cut the miter, you could run the back of the molding over a jointer and then could plane the lip parallel to the back assuring that the the back and the lip are straight and parallel to each other, you'd have a good chance of cutting a good miter. How many feet of molding are straight? Sure you can hold the molding flat against a fence as you cut it and then the miter will be close to exactly 45 degrees to the back, but only until you let go.

We have the best saws and joiners money can buy, and perfection conststantly elludes our frame maker (12 years experience doing nothing else 8 hours a day).

You need a strategy for imperfect miters. Ours is the use of bar clamps (we use Bessy K Body clamps-we have about 40 of 'em in varying sizes, 2 are a little under 96"). Once you have v nails in 4 corners of a frame, you can do a lot to tweak its corners by applying 4 bar clamps. Bar clamps can
apply orders of magnitude more pressure than the nearly useless web clamps and allow, with the addition of matboard spacers, a great deal of control. I've yet to see a corner (of a completed frame) that the clamps can't save no matter how far south it has gone. In a run of 30 different frames, it's not unusual for us to have to resort to the clamps on 4 of them. The clamps and glue make perfect corners but not from perfect miters.
 

Framerguy

PFG, Picture Framing God
Joined
Apr 12, 2001
Posts
7,261
From
Destin, Florida
So Jason, you didn't give any specific examples of what you don't like about your miters. Where are you having the most problem? Is it in the cutting, lining up, joining, or overall look?

For every little faux pas that you can identify with a mitered joint, there is probably a little tweak that can help improve that particular portion of your joint or its finished look. For example, if you are finding out that the very outside vertical portion of your miter is always open when the rest of the miter is tightly closed, it may be that you are putting your outermost v-nail too close to the apex of your miter joint. That will cause the wood fibers to be forced outwards (spread) and open the very outside edge of the joint. If you move your outermost v-nail in a few mm's you will find that this small gap will diminish or disappear completely.

There are so many little things that can cause a miter to look "not perfect" and many of them can be solved very easily. Sometimes it depends on the type of wood, hard or soft, other times it may be a flaw or knot in a perfectly good piece of wood. Some require a little more work and there may be some that simply need some putty! :eek:

(When you get to the point where you are getting "perfect" miters, please email me!!)

Framerguy
 

JRB

PFG, Picture Framing God
Joined
Aug 12, 2000
Posts
7,106
From
San Diego, CA
Why do you want perfect, are you planning on competing with the Gods?

One of the tests to determining if a Navajo blanket is authentic is to find the flaw, they would deliberately put one in, if there wasn't one, just so they would not be competing with the Gods.

Don't you understand how you can completely screw up your Karma by having such lofty ambitions?

Do the best you can, with the equipment you have, make sure you have a good blade. Make sure your work is thoroughly clamped before cutting. Take your time, think it through.

Forget trying to be perfect, nobody is perfect.

John
 

Dave

SPFG, Supreme Picture Framing God
Joined
Jun 11, 2004
Posts
13,355
From
Edwardsburg, MI
Most of my equipment my grandfather bought (some used) in the late '50's early 60's. It still works wonderfully, but life at the joining table was made much easier after I bought my Italian made Alfamacchine mitre sander. Mine was a demo and I bought it from a distributor for $ 400.00.

Italians make sexy machines. It's a very simple, but beautiful, machine tooled well. I always buy myself a Christmas present first to get it out of my system and this was it.

It is also wonderful for taking a smidgen off a length of moulding to assure a frames squareness.

Good tools are inexpensive the earlier you buy them in life...you get more use over time.

Dave Makielski

PS I'm sure I'll now get oodles of calls from Saw, CMC, V-nailer, paper cutter, joiner clamp, Morso cutter, exhaust system, heat and vacuum press, daylight lighting system...you name it manufacturers...

Yes, I know I should follow my own advise and upgrade much of what I have. Convince me and it's done. I'll buy a new piece of equipment each Christmas!
 
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