Quick “which domino to use” question

[smirak]

So, I’m making a panel glue up for a bench in my bedroom. Wasn’t paying attention and milled my lumber to right around 0.6” thick. I have 5, 6 and 8mm dominoes with cutters (df500).  I’m currently in Orlando and always stop by that woodcraft when I’m in town as I don’t have one local. Would the 5mm dominoes be sufficient (i.e. not too big), or should I pick up the 4mm cutter and dominoes?  Rule of thirds says I should be fine?

Thanks,
Kevin

 

[cpw]

So, I’m making a panel glue up for a bench in my bedroom. Wasn’t paying attention and milled my lumber to right around 0.6” thick. I have 5, 6 and 8mm dominoes with cutters (df500).  I’m currently in Orlando and always stop by that woodcraft when I’m in town as I don’t have one local. Would the 5mm dominoes be sufficient (i.e. not too big), or should I pick up the 4mm cutter and dominoes?  Rule of thirds says I should be fine?

Thanks,
Kevin

I'd be skeptical of using the 4mm for anything structural; I have used them on 1/2" work and don't get the same sense of confidence that I do with 5mm or 6mm dominos.  They're only 20 mm long, in addition to being thinner.

 

[Stone Message]

Hi Kevin

The 5 mm dominos will be fine as you expected anyway.

With a long straight face to face glue-up the surface area of the joined faces will be very large and the overall strength of the joint should be gained from the face to face glue line. Dominos need only be used to ensure perfect lining up during assembly and whilst the glue goes off. So, technically, you could just about get away with the 4 mm dominos for that but, as cpw says, one gets a bit more confidence from a more substantial domino.

Peter

 

[Birdhunter]

I would be careful of applying too much glue to the tenons and causing a hydraulic blowout as the stock is thin. I usually cut exact (narrow) mortises on one board and medium mortises on the other. In your case, I’d cut both with the medium setting to allow space for the glue to squeeze out. The 5 mm tenons should work.

I’m cautious so I’d do a test piece with scrap before working my project wood.

 

[ear3]

Just to confirm -- the boards in question will be edge joined to form the top of the bench?

If so, then 5mm will be fine, as others have said.  The dominoes will be performing more of an alignment than a structural function in any case.

 

[smirak]

Just to confirm -- the boards in question will be edge joined to form the top of the bench?

If so, then 5mm will be fine, as others have said.  The dominoes will be performing more of an alignment than a structural function in any case.

That's correct.  And thanks to all for the confirmation...as luck would have it, Orlando store doesn't have a 4mm anyway!

 

[Birdhunter]

If you decide later to use 4mm, I suggest buying a backup bit. I’ve found them to be somewhat fragile.