Domino cutter slots too tight for dominos.

[bobgillis]

I used a micrometer and measured the thickness of the dominos I have and they are the correct thickness, about 0.001" smaller than the size listed.  This means the cutters (5mm and 6mm), that came in the the Festool Assorted Domino Beech Tenons and Cutters in T-Loc Systainer, are undersize.  I need to sand the dominos a lot in order to insert them in the slot.  Is this common?

 

[squall_line]

The dominos have been known to swell from humidity.  Some people who live in more humid climates store theirs with desiccant packets.  Some have had luck microwaving their tenons for a few seconds to drive the moisture out and shrink them down as needed.

 

[luvmytoolz]

We have pretty high humidity here in Melbourne, so most times mine are really hard to get in. I just give them a whack with the hammer. Never had a problem with any despite how thick or thin the boards are.

In short, I wouldn't worry about it, only sand them if you plan on doing a dry fit.

 

[Crazyraceguy]

As squall-line suggested, swelling is likely an issue. I learned the microwave technique long ago for biscuits. This prompted me to store them better. Enclosed containers, like Zip-lock bags are fine, but cannisters work too. Keeping them air-tight as much as possible, is best. This reduces the impact.
Tapping them in as luvmytoolz said, is very common. The fit is supposed to be solid and repeatable.
Most guys will "save" a handful of them that are sanded to a slightly looser fit, for test fitting assemblies, since they can be challenging to remove. Mark them somehow and use them again later.

 

[ChuckM]

In the old days. I, too, microwaved the dominoes because I used the same dominoes for dry-fitting, The extra step is no longer necessary after I made a bunch of dry-fitting (sanded-down) dominoes for each size (except the 4mm ones as I can easily pull them out with a pair of pliers after dry fitting).

For assembly, I hammer them home with the white face of this light-weight mallet:https://www.leevalley.com/en-ca/sho...111433-halder-simplex-replaceable-face-mallet

 

[rst]

I keep mine in zip locks with small bags of dissecant that come in lots of merchandise.

 

[Mini Me]

As squall-line suggested, swelling is likely an issue.

But he measured them to be in tolerance of Festool's numbers so how can that be an issue.

 

[luvmytoolz]

As squall-line suggested, swelling is likely an issue.

But he measured them to be in tolerance of Festool's numbers so how can that be an issue.

When I started making my own wider tenons I found the Festool one's could vary quite a bit within the same size (and storage conditions), so I just thump them all home with no issue!

 

[rst]

At one point I was having trouble with tightness. I was sanding the dominoes to fit.  Finally it occurred to me to put my magnifying glasses on and look at the cutter.  Turned out that the tiniest tips of my cutter were chipped thus the slot was thinner and narrower.  Got a new CMT cutter and voila, dominoes ow fit perfectly again

 

[Mini Me]

I also use the hammer method and if I glue them (rarely) I drill a small hole in the Domino for excess glue to escape. I saw someone destroy a job because of hydraulic locking caused by excess glue on Domino's.

 

[luvmytoolz]

[member=58818]Mini Me[/member] I use the Frontline panel clamps and the force they exert is just astounding, so I always slowly crank them up allowing the excess glue time to exit the joint. I'm sure if I cranked them up fast things would go really bad really quick!

I also have a Frontline pneumatic panel clamp, but I don't dare use that on panel glue-ups where I'm using lots of Domino's, or if I do, I take care not to put as much glue.

 

[ChuckM]

Are you guys flooding your mortises with glue? A little goes a long way. I always put thin coats in the mortises and on the dominoes as well as the edges (if a panel joint). I've never heard or experienced about "exploding" joints like the one you described from anyone in real life. I know quite a number of domino users here, a couple full-time users as cabinetmakers.

Btw, I find this the best apparatus to apply glue for loose tenon joints after using brushes, drink stirrers, and scraps:
https://www.leevalley.com/en-ca/shop/tools/supplies/applicators-and-cups/114776-glue-spreaders

The size is right, and the clean up is easy, unlike the silicone spreaders.

When used with this, putting too much glue is a thing of the past, if any:
https://www.leevalley.com/en-ca/shop/tools/supplies/applicators-and-cups/76086-dripless-glue-bottles

I hate cleaning up excessive glue sequeeze-outs and will try everything to keep them to a minimum.

 

[Michael Kellough]

I put one drop of glue on the end of a bamboo skewer and swirl it around in the mortise and one drop on the Domino then wipe it around all sides with my nitrile glove covered finger. In this case I only want glue on one end of the Domino. Seldom have any squeeze out this way.

 

[woodferret]

I used a micrometer and measured the thickness of the dominos I have and they are the correct thickness, about 0.001" smaller than the size listed.  This means the cutters (5mm and 6mm), that came in the the Festool Assorted Domino Beech Tenons and Cutters in T-Loc Systainer, are undersize.  I need to sand the dominos a lot in order to insert them in the slot.  Is this common?

Sand the corners, not the faces.  You probably only got it in because you sanded so much that it canted enough.  It's the corners that suffer the most from swelling.  You're not going to see it in thickness.

 

[ChuckM]

The reason I find the DF500 a game-changer is its efficiency as a joinery machine. I'd have been very, very hesitant to acquire a machine that would require me to do something about its consumable every time before I could use the machine.

I can't imagine myself drilling holes in the dominoes or sanding/planing the tenon edges in order to use loose tenon joinery in my projects. I buy dominoes in bulk packs and that'd be how much drilling and sanding are at stake. Milling the mortises with the DF500 is already enough drilling for me.

It defeats the purpose of using loose tenons if so much extra work is needed to get the domino joints done.

That said, we all can have different interpretations of the word of efficiency.

P.S. For the record, except for structural joints (which are always narrow to narrow), I use narrow mortises on one piece and wide mortises on the mating piece with a narrow mortise (the first) for alignment purposes. With dry-fitting as part of the routine, final assembly blues are very rare.

 

[Michael Kellough]

I often swipe a file across the end of the Domino before insertion or adding glue. Always on the ends that will be sticking out when joining the boards. Makes getting the alignment started much easier and is well worth the time investment, especially if glue is involved.

 

[ChuckM]

snip.
Tapping them in as luvmytoolz said, is very common. The fit is supposed to be solid and repeatable.
Most guys will "save" a handful of them that are sanded to a slightly looser fit, for test fitting assemblies, since they can be challenging to remove. Mark them somehow and use them again later.

By coincidence, yesterday I came across this, someone making dry-fitting dominoes (a hair smaller than the regular dominoes) out of a 3D printer:

[attachimg=1]

 

[Crazyraceguy]

As squall-line suggested, swelling is likely an issue.

But he measured them to be in tolerance of Festool's numbers so how can that be an issue.

I suppose it's just a "relative" judgement thing. Everyone's idea of how tight the fit should be, may be different.

I can't imagine having to "work on" every single Domino though? I have cut/inserted literally thousands of these things, no time for that kind of stuff.

Over gluing can/does cause problems. You can get hydraulic lock, where it takes a lot of clamping pressure to get the joint to close up. It can even split your parts and have glue come though the grain.

On panel glue-ups (edge to edge) I don't glue the Dominos at all. The strength is in the glue, the Domino is just there to keep the parts from moving, as the clamps are tightened.

 

[Mini Me]

I rarely glue Dominos as I use them as alignment aids. I have used the Domino outside what Festool designed it for and then glue will be used but that is rare as well. 

 

[luvmytoolz]

I'm the other extreme, I glue everything in sight! Every surface that touches anything gets glue!

I have though stopped using the wider slot in general, pretty much all my joints now are on tight setting, which not that it matters probably, but hopefully adds a little more glue contact on the sides of the tenon.