Building cabinet doors with domino

[lambeater]

Morning guys, just startind building a 21" x 30 inch cabinet door that will have an insert fitted (glass or panel) so back will be grooved. The rails are all 2.75 inches wide. Going to dominoe this door together and use 6mm dominoes. Question is do I try to fit 2 dominoes or just use one for each joint.

thx
Lambeater

 

[ericbuggeln]

Ive used one in that instance, Eric

 

[fritter63]

hmm, tough one. I just made a door with 3" parts and I put in two, but it did feel a little tight.

I don't understand Festool's guidelines for have "2d" distance between cuts because once glued in the dominoes make for solid filler and the ends of tenons aren't where the stress forces are applied anyway.

 

[mouppe]

Two dominoes may be tight because the inner one may run into the groove for the glass.

I used one on a door with similar dimensions recently, but pegged the domino for additional strength.

 

[Tim Sproul]

I've made similar sized doors.  I use a single Domino but I make  my own Domino stock to fit the medium width mortise.  Make the crossgrain mortise as deep as possible.

 

[Sparktrician]

I would use two per joint; one straight across as in normal practice, and one coming in from the top (or bottom) in line with the joint edge line, but not so deep as to make contact with the cross-joint domino.  There will be a portion sticking out which will need to be trimmed off.  This will strengthen the joint by providing much more gluing surface for the joint.  I'll have to give Brian Sedgeley credit for this joint.  This was discussed and used in the Doors & Drawers class at Lebanon. 

[smile]

 

[mouppe]

Oooh, I like that idea. I suppose you would have to glue or cramp the door up first and then route the mortise?

 

[Tim Sproul]

This will strengthen the joint by providing much more gluing surface for the joint.  I'll have to give Brian Sedgeley credit for this joint.  This was discussed and used in the Doors & Drawers class at Lebanon. 

[smile]

I don't think this adds much significant strength to a frame.  Why?  Think about how weak a frame is if you were to take a wide panel and just saw out the middle, leaving a frame made from a single piece of wood.  This frame is very weak and easily breaks where the long grain is the shortest.  The long grain is the shortest where a traditional m/t frame has joint lines.  The cross grain nature of a m/t frame joint gives the joint strength.  In addition to glue surface area.

 

[Sparktrician]

Oooh, I like that idea. I suppose you would have to glue or cramp the door up first and then route the mortise?

Right.  Either way would work.  At least clamp a dry fit with the cross-joint domino in place before cutting the second mortise.  If one uses a contrasting domino (sipo domino on a maple or cherry frame), it adds some visual interest.  I should add that it's best to use the tightest mortise width setting on the tool. 

[smile]