Useing the Festool Domino to make wider planks

[Jerry White]

Chris,

Now you really are asking me to embarrass myself! I really don't have an explanation for mortise size changing with plunge rate, beyond pure speculation. All I know is that I picked up the tip, experimented with it, and it worked for me. Keep in mind that here I am speaking of clearance along the narrow dimension of the mortise and not the longer dimension of the hole.

I would speculate that the higher plunge rate introduces a bit more "slop" or tolerance than a very slow controlled plunge. You might give it a try and see if it works for you.

As an aside, I am with those who normally do not use the dominos for alignment in edge jointing.

[John Keeton]

I haven't used my Domino all that much, but in my practice runs I noticed that I was not holding the machine (and the flip down fence) tight to the wood. The angle of a couple of my mortises was ever so slightly off. That can really mess up a joint! And, it doesn't take much

[Narayan Nayar]

For me, nothing beats the Domino for edge joining boards. The dominos prevent me from needing cauls across a panel, and they eliminate that last minute realization that the boards slipped as you were tightening down clamps and now you have to sand or plane down 1/16" then plane the panel to constant thickness.

I've tried multiple methods: splines, biscuits, cauls, edge-gluing bits, straight glue, etc. and I've settled on the Domino or straight glue as my main methods. Here's some of the things I do:

1. Arrange the boards for desired appearance/grain direction
2. Mark off the final length of the panel across the boards
3. Draw some random lines where the boards meet. In this application, the Dominos are just for alignment, not strength, so I don't need many. Sometimes 2-3 are more than enough.
4. Register cuts off the fence. I flatten my benchtop regularly enough but it's easier just to register off the fence.
5. As others have suggested, I usually use the tight setting for one side and the looser setting for another. Sometimes I use the tight setting for the middle or end on both sides, then use the looser setting on both sides for the rest of them.
6. If I feel I need to dry fit (I usually don't for this application; for joinery I always do), I have a set of Dominos which have their edges (the rounded bits) lightly sanded. These Dominos are marked DF with a Sharpie.
7. Glue the sucker up!

I had moderate success with a biscuit joiner. Biscuits fit much more sloppily than Dominos, so when using them for edge joining, you still have to be very careful. The Domino has basically taken the worry out of gluing up panels for me; it's almost mindless. I'm sure some people are this way about other methods.

[Chris Padilla]

The Domino has basically taken the worry out of gluing up panels for me; it's almost mindless.

I wouldn't say "mindless" but perhaps "error-free or comfortable" once the pattern has been established.

I could see myself easily using dominos for large board glue-ups (wider planks) as they are excellent for alignments. If you've got a warped board, the domino will keep it straight assuming you've cut the mortise appropriately.

[Wade Lippman]

I don't use dominoes for making panels. Biscuits work just as well and are easier.

However, in joining cabinet tops to sides (which isn't all that different than panels, except you need the strength you get from dominoes) I cut one side all tight and the other side progressively looser. That insures that a tiny error won't make assembly difficult.

How many you need for your panel depends on how flat your wood it. Dead flat and two are plenty. Not so flat, more...

Go real easy on the glue; the fit is tight and too much can make assembly difficult if the glue has nowhere to go.

I have sanded down a bunch that I use for dry fitting, and put a hole on them so I don't get them mixed up.

[Neil Clemmons]

Michael -

You might also try putting the domino tenons in the microwave and they will slip more easily into the mortises. I do this and it does make insertion and removal easier. You can also stick a strip of adhesive sandpaper on your bench and lightly sand the faces to give you bit more slack if you don't have a microwave handy in your shop.

Chris -

The plunge rate apparently does make a difference in mortise size and orientation. There have been a couple of threads on the Festool Owners Group forum where they referenced some tech notes from Festool that suggested that a faster plunge rate can distort the bit alignment and swing, resulting in a slightly off-kilter mortise, or a tighter mortise. They do recommend a slow, deliberate plunge for best results.

Good luck with the domino -

Neil

[guy knight]

i use the middle setting for most of my projects when i do want a tight fit i use woodcraft's domino's they have slots in them and prevent hydraulic pressure and allow for more glue to be used also i nuke my domino's before use

[John Stevens]

Hi, Micheael. I had many of the same questions when I started using the Domino. Here are some answers I got from other users. I hope they'll be as helpful to you as they were to me.

If you change to the loose setting how do you get the tennon's centered.

First, bore the mortises from left to right on one board and right to left on the other. Remember, you want the holes on each board to be a "mirror image" of the other, so going left to right on one and right to left on the other will do that.

Second, make all of the mortises on one board at the narrowest setting. For the other board, only make the first mortise at the narrowest setting. Then switch the width setting to the middle and bore the rest of the holes. This will always keep the mortises on both sides aligned with each other so the tenons will be centered in the wide mortises.

Make sure to keep the motor running when you switch the width setting--keeps you moving faster and it's the way the machine is designed to be used.

Should I mark the board instead of using the pin guides?

When I join boards into panels, I almost always do it with the boards only cut to a rough length. I then align the boards in the way that gives the best grain and color match. If you also do it that way, then you wouldn't expect the corners of the boards to match on either side, so you'd just use pencil marks instead of the pin guides. When you're joining parts that are already cut to final dimensions, you can save a little time by using the pin guides for the mortises on the ends.

If you do want the corners on one end to line up, always use the pin guides for the first mortise, the one that will be at the narrowest setting on both sides. Then use pencil marks for the other mortises Even if the boards aren't exactly the same length, this will work--the corners on one edge will match up, but the corners on the other edge won't.

If you've already cut your boards to the same length, and you expect both corners to line up, then you may use the pin guides for the mortises at both ends to save a little marking time.

Should I drill with the tight setting to get alignment and then go back and use the wider setting?

Not necessary if you do it the way I do. Also, I've found that when I re-bore a hole with the Domino it often comes out a little too loose in the thickness dimension--user error.

Hope this helps.

Regards,

John

[John Stevens]

How much pressure do I need to put once the dominoes are set in holding for the glue to set?

You only need to use as much clamping pressure as you'd use for gluing up a panel without the dominos. This assumes that you're following the others' excellent advice on this thread about using a thin coat of glue, using different width settings on the two boards, and making sure your tenons aren't too thick for the holes. I keep a hammer handy to make sure each domino has "bottomed out" in its mortise when I insert them into the first board. A little tap will do it, no need to hit so hard that it deforms the end of the domino.

Also, put the clamps so they line up with the dominos and tighten the clamps evenly from one end of the panel to the other--this makes it easier to draw the pieces together. This also means that if you're using more than two pieces of wood for your panel, you need to make sure that the dominos form lines perpendicular to the grain.

I find that if I glue all the tenons into one side, it makes it much easier to assemble the two boards. Which side? The one with the narrow mortises. This procedure also has the advantage of making the glue-up less hectic because you minimize the amount of "open time" you need. Check it out:

First apply glue to all of the mortises in the first board with the little "paddle" applicator sold by Woodcraft. Then apply glue to only half of one tenon and insert it. Since you're already holding the paddle applicator, use that to apply the glue. Works great. Repeat for the rest of the tenons. If the fit is "tight," tap each with a mallet or hammer to make sure it's seated at the bottom of the mortise. Quickly wipe away the excess glue that squeezes off the tenons as you inserted them. Make sure that the halves of the tenons that are sticking out of the board don't have any glue on them, not even a slight film.

Now stop and think--at this point, all of the surfaces that have received a thin coating of glue are now in contact with each other. No need to run around like mad because you're afraid of the glue drying out. Ahh, take a deep breath and let your blood pressure return to normal. Feels great, doesn't it?

Okay, time to put the glue in the mortises of the other board--use the paddle applicator. Next, spread a thin film along the edges in between the mortises--I like to wipe or dab a thin film with a foam brush because it gives a nice, thin even coat that produces very little squeeze-out. Now switch to the board with the tenons sticking out of it, and use the foam brush to put some glue in the spaces between the tenons. Now put a thin coat on the exposed halves of the tenons--since I'm already holding the foam brush with glue on it, I use it to apply the glue. Works great. Line the tenons up with the mortises and place the boards on your clamps. Line the clamps up with the dominos. (I always put brown paper down on my workbench to keep the glue from dripping on it, so I draw marks on the paper to show me where to line up the clamps so they'll line up with the rows of dominos.) Tighten the clamps evenly from one end of the board to the other, a little bit at a time.

Also over 18 inches how many Dominoes should I use

No hard and fast rule here--for alignment, it depends how flat your wood is. As a rule of thumb, I'd put them every four to six inches, depending on how well the boards lined up.

(Disclaimer--I have used dominos for aligning panels while clamping, but I have special clamps that make this unnecessary, so I haven't used dominos for this in ages.)

Hope this helps.

Regards,

John

[John Stevens]

It's also possible you hydraulic the domino with glue. I recommend brushing just enough foe glue on the surface. Don't squirt glue in the mortise. Once you get used to the Domino you'll love it.

Great suggestion, Bill. I have also found that to be very important. Woodcraft sells little plastic glue applicators that are paddle-shaped. They are just the right size and shape to apply a nice thin coat of glue to the insides of the mortises. I keep some glue in a short, wide jar so that it's easy & quick to dip the paddle into the glue.

These paddles work as well as anything else (including acid brushes) to put a thin coat of glue on the tenons as well as the mortises.

Regards,

John

[Paul Johnstone]

I'm with those who suggest that the Domino might not be the best tool for edge joining. Biscuits would be a more logical choice although,

I agree. I've tried both, and biscuits are much better at edge to edge jointing. I know dominoes can work, but biscuits are quicker and less fussy and get equal results, IMO.

The domino excells at other tasks though.