Clamping frame corners to bring them in

[Nick Tonks]

Hi
I am using an old Morso underpinner sometimes the the frame corner is not as tight as I would like. I was wondering if anyone clamps the bad corner while the glue is still wet and if you do what clamps have you found work well for this. I get this problem if there is a slight twist or warp in the moulding.

[Val]

We glue and vise all of our corners first, let set up for a few minutes and then v-nail. Our v-nailer is an older one and doesn't have the supporting fences and tends to push the miters apart if the glue is still wet. It takes a little extra time, but saves it in the long run (for us) because they never pull apart, so they don't have to be re-done.

We use the Stanley-type miter vises, the heavy, adjustable cast-iron type, not bolted down, and have 10 (or 12?) of them (We were recently given 6 !), so we can have several frames going at once.

[Richard Darling]

I will often clamp the offending corner first and let the glue dry, then move it to my underpinner. There are times when I can get the corner to come together properly in the underpinner because of the shape or the way the pressure is applied (could also be my inexperience), and clamping the corner first solves the problem.

My clamp is actually an old Pistorius manual lever-arm underpinner. I took off the pinning assembly and just use the clamp.

[FramingFool]

Forcing any joint like that invites a future separation ... you should invest in a mitre sander to get those corners to fit easily first ....

[orlando]

I always glue, then v-nail each mitre and while the glue is still setting use a couple of Bessey K-Body clamps (http://www.jamesmorton.com/products/wood/KBody.php) to compress the corners together for about 10-15 minutes. The mitres will not slip as the v-nails are already in place.

For really tough corners I will use 4 of these clamps and arrange them into a frame press (http://www.jamesmorton.com/images/kbody_pic2.jpg).

These clamps are a bit pricey but real sturdy they will outlast you. I find that this works for me.


cheers,
Jose

[orlando]

K-Body clamp frame press. (link didn't work on the previous post)
http://www.jamesmorton.com/images/kbody_pic2.jpg