Bl Working

a pretty good miter gluing jig

cherry, walnut and abalone mirror frames ....
what have we here? im going to go out onto a limb and say we have just come up with the definitive best miter gluing and assembly jigs yet. i dont usually make statements like that, as i know there are untold methods to get the same results. but, that said, this ones pretty good. and, over the years, i have tried a lot of ways to skin that cat ... inherent in gluing four sided picture framelike objects is the clamping problem and the moving problem ... how do you keep all four corners of a frame lined up, the miters tight and the frame square? weve glued them up, it seems, using endless strategies and techniques, none of which, in the past, would i have said were easy and 100% successful ... suddenly, friday, an inspiration struck, as inspirations sometimes do, and now i feel we have solved a tricky problem once and for all ... click the photos to enlarge them ...
ok, the challenge ... to help scott with his show, (see the previous post), at the last minute, (thursday night) he needed two sort of large picture frames, (+/- 39 x 60 x 2), painted black ... will said he could do them and we were off.
in the past six months or so we have made at least a half dozen or more mitered frames with abalone details (scroll down), and we know that it can be a tedious and fussy task ... get those miters perfect on all four corners. yeah, right ...
so, i had this idea ...

* take a piece of square mdf 14" x 14" ... really check it for square. length parallel, width parallel, equal diagonals, etc ...
* set up your 3/4" dadoes and run a groove 3/8ths " deep, parallel to the edges, the width of your frame stock in from the edge ...
* make some 1 1/2" wide 1" thick pieces of something ... i used mdf cause it was hanging around
* notch (rabbet) the corners of those strips (for rigidity), get a nice fit and glue them into the dadoes, and fasten the corners ... see the drawing above and the photos below ...
* try as best you can to be accurate with these corners too as they will tell you about where to clamp your first piece of mitered frame stock. see below .
* add pieces the exact thickness of the frame stock rabbet around the verticals (these can be removable for future different frame stock, to allow the mitered pieces to sit flat on the jig ..
* cut the finished square into four pieces

to use it:

* cut your four mitered pieces and clamp up your first corner, eventually clamping all four corners and checking the diagonals of the frame for square when youre finished ...
* if youre good to go, unclamp and glue each corner in turn. when youre done, you should have a perfectly square, glued up, mitered frame.
works for us .... itll probably work for you ...