heavy picture frame

technically, you don't need the top. the glass and lead panel will sag due to weight. without a bottom support, the panel will wind up on the floor and the top of the lead or zinc glass frame will still be attached to the top piece of the wood frame. the larger the panel, the sooner this will occur.

From an engineering standpoint there is no way to know this. Depends on the frame, thickness, width, wood, size, weight, glue, biscuit size, etc. Biscuits are not the strongest joint, but may or may not be adequate for your application. Get extra strength using metal "L" braces, which you could mortise.

A Butterfly Dovetail Inlay centered on the miter cut in a contrasting wood also looks nice, and adds strength.

NICE!!!! I just need to figure out how to cut it!

technically, you don't need the top. the glass and lead panel will sag due to weight. without a bottom support, the panel will wind up on the floor and the top of the lead or zinc glass frame will still be attached to the top piece of the wood frame. the larger the panel, the sooner this will occur.

Well I wonder how long that takes to happen. I have 2 pieces in my home that I made in the early 80's that are similar in size and they hang from a chain on each corner, no sag yet.

That said, on larger panels we soldered a support as inconspicousely as possable from the top of the frame to the bottom of the frame.

DejaVoodoo wrote in news: snipped-for-privacy@q37g2000vbn.googlegroups. com:

Not difficult. The bottom piece is a simple half lap, then cut the miter.

The top piece could be cut with a dado and the piece on a 45* miter. I'd probably cut this piece first, then the other to fit.

Biscuits are for placement. Preventing lateral movement while the glue dries. In some softer woods, the biscuit might be stronger.

Mart> I have been asked to make a frame for a stained glass window. The

What about spline joints? Lots of strength and they wouldn't be visible.

Here is the joint I was talking about:

You could also use flat metal "L" brackets on the back.

I used to make my own frames (various sizes up to 40"x60"), always glued the miters with cyanoacrylate glue, no brackets, no nails. Never had one come apart but they were only holding canvas on stretchers. The joint needs to be smooth though and if it is a chopped joint it won't be; the trick with those is to rub over the surfaces with a piece of chalk...the chalk fills in the low spots, the glue soaks into the chalk and binds it to both the wood and the mating surface.

Mitered half laps,or mitered bridle joints, (sometimes called mitered slip joints), would work.

If your not sure what I'm talking about, search Google images. I pulled up a bunch.

Lots of good info on this page:

I saw a frame made with those joints, with the addition is tapered pegs through the mortise and tenon. Cool part, is it had NO glue. You could pop the pegs out and take it apart.

Steve is right on. I really like this mortised miter idea for the OP. It is strong, traditional, classic, and low cost. Easy to make a table saw (or router table) jig using from the wood scrap bins.