Domino Counseling

[Lorin]

I have a Domino 500 and am making 2 ea 5.5” square staircase newels 40 inches in length with 3/4” rift white oak material that I have ripped at 45 degrees.  The first newel I used 6X40 dominos cut down to 24mm length, set the angle at 45 degrees, height to zero, depth of the cut to 12mm, and spaced  them 6” apart.  The first newel turned out fine but  I was a little harried in gluing up 28 dominos.

How would an experienced Domino user approached this setup?

 

[Birdhunter]

I just completed a bed made of quarter sawn white oak and about a million Dominos. I was really worried about the glue up process.  I did my test fit with sanded down Dominos. Once satisfied the fit was correct, I glued the Dominos into the tight fit mortised board being careful to remove all the squeeze out glue. I use the tight mortise on one board and the looser mortise on the other board. After the tenons had time to dry, I spread glue on the others (about 8, 1 every 12”). I inched the boards together using clamps and a dead blow hammer.

The newels you describe, I’d make with tenons every 12”. The 45 degree joints provide lots of glue surface and you don’t need a lot of tenon strength.

You must have excellent Domino technique to lay the mortises in at a 45 degree angle. That’s tricky.

 

[ear3]

As other have said, the dominoes on miter joints are more for alignment than strength, so along a 40 inch length, I would be comfortable doing 5 or 6 dominoes per joint.  Use Titebond III or something similar that has a longer open time, as miter joints can take a while to set up and clamp properly.  I tend also to use 5x30mm dominoes when doing miter joints with 3/4 material, but there's nothing wrong with using 6mm -- just an extra step to cut them down.   

 

[ChuckM]

Why would some of you think the use of dominoes in a mitre joint is for alignment and not for strength?

A mitre joint (endgrain to endgrain) is weak by itself. That was exactly why I used dominoes (face grain to face grain) on my last few mitre joint constructions.

If the dominoes do not provide extra strength (through the extra face-grain glue surface), what is holding the weak mitre joint together? Could someone please expand on their reasoning?

 

[ChuckM]

Thanks. I thought we were talking about the typical mitre joint.

 

[johntheoak]

The joints are called bevels, not miters.

 

[Naildrivingman]

The joints are called bevels, not miters.

Important point.  Thanks for that observation!