Best way to make this joint?

[Chip Gaber]

Hopefully my stick drawing came through below.

I've been asked recently to make a 2x2 cedar frame for 2 stained glass panels. The requestor wants mitered corners and no visible joinery. I tried to talk him in to splined miters but he's insistent on no visible joinery since the finished panel will be hanging from chains in his space and viewable from all sides. I will dado the inside of all pieces to fit the panel into and glue/dowel all joints. The frame will encircle the entire panels.

My question is how is the best way to connect the center section of wood to the mitered top piece other than just glue? Circled in red on the image.

Any suggestions appreciated. Thanks!

[Myk Rian]

Just put some biscuits in it

[Yonak Hawkins]

I'm not sure I understand, Chip. Is your drawing in "exploded" mode where none of the components touch each other but, when assembled, all will be joined ? If the way its shown is the way it will be, maybe you could "link" all the parts with chain links, using the same chain as the chain hanger.

[Charles Taylor]

I'm trying to interpret your meaning as well, and I think you want to know how to join the vertical piece between the two panes of glass with the mitered joint at the top. Here is one relatively straightforward idea.
318884
Depending on how confident you are in your saw and chisel skills, you could make the stubby tenon on the vertical long enough to extend beyond the groove for the glass and act as a spline for the miter joint, but not so long as to come out the top and be visible, thereby keeping the requester happy.

[Mike Schuch]

I Would use dowels for that joint. Depending on what dowel jig you own you are going to have to be a little creative in drilling the dowel holes as two of the holes will be at 45 degree angles. You could drill the dowel holes in the end of the upright piece BEFORE you make the two top 45 degree cuts to make the top into a point. You will have to drill these two holes much deeper than regular dowel holes to compensate for the 45 degree chunks you will cut off.

[John TenEyck]

Since you said the frame will encircle the entire panels, glue is all you need when joining edge grain to edge grain. If you just have to do something to feel better about it, I'd vote for a spline or stub tenon.

John

[Art Mann]

What is the thickness and width of the pieces making up the frame? If the material is large enough, then a Dowelmax or similar first class doweling jig will do the trick nicely. In that case, drilling dowel holes into the mitered ends at the correct angle is easy. A Festool Domino will also do the job but the initial cost for the machine is considerably higher.

[Tony Zona]

What are the measurements of the glass pieces?

[Chip Gaber]

Thanks Gents,

My apologies for the unclear drawing and explanation. I need to learn Sketch-up! I do not own a biscuit jointer.

Great input thanks. The stub tenon seems like an easier and just as effective joint to me after thinking about it. I have the Jessem dowling jig but I will still need to create another jig for the 45 deg holes...unless I drill the holes after I miter the center column, perpendicular to the 45 degree faces...And that puts the dowels at a better mechanical strength than vertical? The dado is only 1/4" deep so that gives me plenty of space to bury any dowel/tenon. Ok, I need to get thinking on this one. Thanks for the inputs.

[Chip Gaber]

Looks like I responded at the same time as other posters.

The size of all the wood is 2x2 inches varying lengths with 1/4 " dado right in the middle. Each glass panel is roughly 18" wide by 36" tall (at the peak)and each glass panel is bordered by a 1/2" lead double channel which holds the glass. I backfilled the outside channel with a strip of wood flush with the lead so the dado would have something to hold on to.

[Max Neu]

You could do the spline like you originally wanted to,then veneer over it to hide it.

[Lee Schierer]

If the stained glass is going to be siliconed into the grooves in the three pieces, there is no need to worry about the strength of the mitered joint.

[Chip Gaber]

If the stained glass is going to be siliconed into the grooves in the three pieces, there is no need to worry about the strength of the mitered joint.


Interesting Lee. My drawing is incomplete. I did not draw the rest of the frame. It will be completely encased with a frame. That aside, I hadn't considered silicone and that bonding strength. I wonder how silicone bonds to lead, which is what the glass frame is made with. I have attached a link to the glass panels for clarity.

glass panel: http://www.pbase.com/chip_g/image/160926457.

[Mike Schuch]

Drilling the dowel holes in the center piece on the 45 flats would give you more strength against downward forces. I don't know if that is needed but it certainle wouldn
t hurt. Are you going to use any joining technique between the two top pieces? That would make 45's on the center piece harder to assemble... harder but far from impossible... all 3 pieces would have to come together at once.

[Yonak Hawkins]

Is there any reason why you couldn't go up through the center piece into the top pieces with screws through the dados ?

[Phil Mueller]

I would reconsider the placement of the chain. Where it's shown connected in your drawing, I would assume a lot of stress on the top miter joint given the size and weight of the glass panels. I would probably connect the chain through the angled top into the vertical side pieces and make a solid joint between the vertical pieces and the bottom piece. That would make the strength of the top miter less critical. I agree silicone or something to adhere the panels to the wood would also add strength.

[Yonak Hawkins]

I would reconsider the placement of the chain. Where it's shown connected in your drawing, I would assume a lot of stress on the top miter joint given the size and weight of the glass panels. I would probably connect the chain through the angled top into the vertical side pieces and make a solid joint between the vertical pieces and the bottom piece. That would make the strength of the top miter less critical. I agree silicone or something to adhere the panels to the wood would also add strength.

I'm not so sure. I would think the chain placement is right .. in the middle of the heaviest elements.

[Brian Holcombe]

Secret dovetails at the corners of the outside frame and stub tenons for the center beam.

[Robert Engel]

Mortise and tenon or floating tenon

[glenn bradley]

I did not draw the rest of the frame. It will be completely encased with a frame.

Ah, there it is. I too would tenon to assure a long life of good alignment on that very soft wood but, I'm just that way. The quick-n-dirty way would be glue at the butt joints with a bead of silicone in the dado all the way around. I have mounted 18" woofers using only silicone in a rabbet and dropping the speaker in using its own weight to press into the silicone. Twenty years of rough and tumble use and the speakers are still mounted rock solid with only the silicone holding them in place.

[Chip Gaber]

I know its been awhile but I figured I'd post some picks of this completed project. Its been done for awhile and my friend loved it.

Decided to go with stub tenon where the vertical meets the top of the frame:
331564

And same with the bottom:
331565

All frame joints were tight and double doweled and glued. I used a little silicone caulk along the top edges of the glass to hold it steady in the groove. Worked out great. Thanks for the great suggestions!

Finished piece:
331566

[glenn bradley]

She looks great Chip. Thanks for sharing that.

[Keith Pleas]

I'm not so sure. I would think the chain placement is right .. in the middle of the heaviest elements.
I think it's going to be very tricky to get two chains to hang at exactly the right lengths to keep this construction perfectly vertical. And without seeing the entire plan, I also don't like hanging them in the middle of the cedar, which I think is going to deflect over time under what looks like considerable weight from the stained glass panels.

I'm not an engineer, but I would look for a way to hang the bottom most piece and then build UP from there.