Miter Clamps

[RickT]

Yes, it's true. A woodworker can never have too many clamps. I'm looking for miter clamps. I'm doing more window casing (trim), and I'm thinking of using a method described in Fine Homebuilding. The method is to use biscuits in the miter joints. Has anyone done that? I'd like to cut, biscuit, glue, assemble, and clamp the miter joints, so I end up with a complete unit (like a picture frame) that can be nailed up to frame the window. Unfortunately, most miter clamps are designed to clamp your work at a "perfect 90 degrees," as if that's the desired angle. But life isn't always 90 degrees. Sometimes it's 89 or 91, and when you use one of those "perfect 90 degree" clamps, you end up with an open joint. Anyone have comments on clamps they've tried successfully, and even unsuccessfully?
Thanks,
Rick

P.S. I'd like to share a phrase, which I can relate to, I read on another forum. I laughed when I read it, and it makes perfect sense to me. Here it is:

"I suffer from CDO, which is like OCD but in alphabetical order, as it should be."

(OCD = Obsessive Compulsive Disorder) Just in case you were scratching your head on the acronym.

[Sawatzky]

I think I think I think I might be a little OCD.

[Tequila]

I love my spring miter clamps for doing what you're talking about. This is the set I've got, but there's plenty of others out there:

http://www.hartvilletool.com/product/11189

[poolhound]

I am not sure I really understand your issue, If you are building a frame then dont you want all the corners to be 90 degrees?

If you are saying that you are trying to frame an opening where the corners are not exactly 90 degrees then you would have to cut each piece individually and miter the angles accordingly for each joint. If its that far off, attaching each piece on its own would seem easier.

[Tom Slick]

I'd recommend spring clamps and glue, no biscuits. If you want the best trim miter clamps take a look at http://www.miterclamp.com/ and check out some of the tips and tricks movies on that site.

I preassemble casing and use 2P-10 glue, no clamps needed.

[niki]

Hi Rick

For a frame to be square with tight meters, a few conditions are a must...

1. Every two opposite frame members must be exactly at the same length

2. the sum of each corner angle must be 90°

3. The sum of the vertical angles at each corner must be 180°

Any deviation from the above will leave a gap in one or more corners and the clamps will not help you so much to close the gap.

There are a few methods to achieve it depends on what equipment you have...for me, it's the TS with sled.

To glue the frame, I use loose tenons (or biscuits) and sometimes splines.

niki

[messmaker]

OH heck, what's a couple of degrees among friends. If you need help getting a miter joint that is not exactly 90 degrees, I might be your man.

[chopnhack]

IMHO, for finish carpentry, if its paint grade your method is correct, but overkill. You will find the work goes much quicker and finished just as well with a smidge of caulk If it's stain grade it might be worth the effort you speak off.

[RickT]

Thanks for the replies. You guys are the best...well, you're at least pretty good. :-) Anyway, the window casing is stain-quality and is being stained, so "a painter's friend" (caulk) isn't an option. I understand and agree with the math for ensuring tight and square miters. However, since home construction, unlike furniture, has what some might call a "slightly larger tolerance." Window jambs don't always sit flush with the drywall, which can make triming the window with perfect joints a challenge. Also, having the opposite pieces of casing the exact length works only if the casing is perfectly straight. I sometimes glue and fit the miter joint and nail (I wouldn't hang casing without my finish/brad gun) close to the joint and then have to "persuade" the rest of the casing to follow the window jamb with a nice 3/16 reveal. All the variables seemed to be simplified in the Fine Homebuilding article about preassembling the casing with biscuits. I found a couple of clamps that seem like they might be useful. Even if not needed for my window casing, I can always use them for other projects.

http://www.woodcraft.com/family.aspx?familyid=3653

http://www.tylertool.com/jor913corcla.html

Thanks again for the great info.

Here's to joyful and safe woodworking!

Rick

[Tom Slick]

what about casing/facing the inside of the window and adjusting it to square, then your picture frame casing can be tight 90s all the way around.

[Tom Slick]

You could give yourself enough reveal, maybe 5/16, so the difference isn't noticeable. Another thing to think about is when everything is glued together you can now bend the material slightly to make up for slightly out of square without the miter opening up.

[Mr__Bill]

I like that cdo....

as to the original question, yes, spring clamps, biscuits and glue. at one time I could buy the trim already made up like that. the biscuits are necessary to keep things lined up as the spring clamps just hold it together and not aligned.


bill, who was lacking in capital ideas today