Dominos - which side do you put in first (endgrain, or face grain)?

[eddomak]

This is more of a curiosity question than anything else, but just wondering if there is any good experience on which piece you tend to put the domino into first, when peforming a typical 90 degree join of 2 boards?

a) The domino into the end mortises?
b) The domino into the mortises in the face of the board?

For 5x30 mm dominos into 16mm I have tended to put them into the face side first which is only 12mm deep, as opposed to the receiving (end grain) side which is deeper than necessary.

But for this 12mm ply project using 4x20, since the mortises are both 10mm deep, I have put them into end grain first.

Everything went together fine in dry fit with some sanded dominoes, but now that I am using full dominoes and trying to do some sub-assemblies first, I find that I need to do a lot of "persuading" using my impact hand tool (ie hammer/mallet). Alignment seemed to shift in some cases. It got me thinking that maybe it could possibly be easier if the dominoes were inserted in the other side first.

Anyway, hope this piques your interest.

 

[Rick Christopherson]

I habitually put the tenon into the edge-grain mortise. The reason for this is due to the glue application. I apply a small amount of glue inside that mortise and insert the tenon. Then when I apply the glue for the end-grain piece, I apply glue inside the mortise and also on the face of the joint. I don't have to worry about spreading glue around a tenon that's sticking out of that mortise.

It's not a big deal to do it any other way, but over the decades (back doing dowel joints) I've made it a habit so that I don't even have to think about it. Plus, there has never been a case where I needed to reverse it.

 

[bertv]

Always in the end. And those are in tight holes, as opposed to the holes in the face, where I use the looser setting except for a registering one at one or two sides (using the inbuilt offset of the Domino-machine).

 

[Stoli]

On whichever side has more material behind it.  I have had issues with not perfectly flat plywood where significant persuasion was required to make the joint come together -- the domino was jammed and blew out the face of the plywood before it seated into the mating piece.

 

[Michael Kellough]

On whichever side has more material behind it.  I have had issues with not perfectly flat plywood where significant persuasion was required to make the joint come together -- the domino was jammed and blew out the face of the plywood before it seated into the mating piece.

In that situation I'd glue in the Dominoes in that piece of plywood first and wait for the glue to dry, or use a wider mortise to allow space for glue to escape so the hydraulic pressure doesn't blow out the face ply.

 

[Roseland]

Particularly in MDF I put them in the faces first, at the narrow setting.  I then use the middle width setting for the edge mortices.

I've found I can burst MDF if I tap a tight Domino into an edge with the narrowest mortice setting.

Andrew

 

[Stoli]

wider mortise to allow space for glue to escape so the hydraulic pressure doesn't blow out the face ply.

I do that as well, now.

 

[eddomak]

Thanks all for your replies. Very interesting.

I am also cautious about hydraulic blow-out, so often put it in the face first (as well as the aforementioned off-set issue) with a nice hard backing behind it to lend support.

I think of course the tight mortise before the loose mortise is good sense, but for my recent project all the ply was 12mm, so I didn't want to remove additional material and lose strength, so all mortises were tight.

The good news (hopefully) for me is that this morning I attached the sub-assembly to the next 2 assembly pieces using test dominoes and it looks like no persuasion will be necessary.  [smile] (But then again, I thought that for the sub assembly..  [eek])