Dominoes in thin material

[nikev]

Folks,

This is another of my "small workpieces" question (following up on the thread below). I'm wondering whether it's possible to put an 8mm domino into a board that is 11mm thick (the material is sapelle, a hardowood similar to mahogany), or whether this will make the joint liable to split. I could use the smaller 5/6 mm tenons, but for various reasons I need a 50mm long tenon, and the 5 and 6 mm dominoes don't come in that width AFAIK (and I don't have any if they do).

I tried to do use an 8mm tenon and found that there was very little material left on the faces parallel to the domino (1.5 mm per side) and it's easy to tear that off, but once the domino was in and glued, it seemed solid and and I not feel any give when pushing the domino pretty hard in the direction where the joint might split.

Any input would be welcome.

Thanks,

Nike

 

[dirtydeeds]

do you REALLY need a thick tennon (50mm long) in thin timber?

it sounds unusual

 

[nikev]

do you REALLY need a thick tennon (50mm long) in thin timber?

I don't need it to be thick, but I do want it to be long if possible (want to expose the end). The 30/40 mm pieces are too short.

 

[Wim]

Why not use standard 5 mm Domino's and glue sawn-off pieces in the remaining spaces at the ends of the Domino's. However you can't use the maximal depth setting with a 5 mm bit.

 

[nikev]

Hmm. That's a thought. Do you think it's crazy to use an 8mm domino in think stock like the kind I have??

 

[Wim]

Using a 8 mm Domino in a 11 mm piece of wood is at least against my logics. There is no strength in the connection.

 

[jakiiski]

I believe the new 4 mm Dominos would be for material that thickness, the mortise/tenons should follow the one third (1/3) rule...  Divide material thickness with 3 for the Domino thickness.

 

[nikev]

I did not know that there were new 4mm dominoes.

That being said, I put the 8mm dominoes in my material (which is actually more like 11.8mm) and tried to split the joint. It didn't split even after I hung the piece off the dominoes on each end and hit it in the middle. It seems like the 8 x 50 dominoes are so deep in the material that the pressure is distributed over a large area and the joint is stronger than it seems on paper. I would not use this for a joint that would be under stress, but since this is a compression joint and not bearing any load, I think it might actually work.

-- Nike

 

[greg mann]

I am interested in what the 'various reasons' are for needing so much depth.

 

[Peterm]

Sounds like one of the (few IMO) times when making your own dominoes might make sense; we're working with wood - if we can't buy what we need, we make it, right??