Under sized dominos

[Oldwood]

I bought the systainer box of dominos with my machine as a package. I recently had a use for the 8mm x 40mm and 8mm x 50mm. The 8mm dominos range from 8mm to 7.8 mm in thickness. I find that the 8mm are usable but when you get to 7.9 they begin to lose the ability to index a surface effectively also without a good press fit the glue joint will be questionable. It seems that about 30% of the 8mm dominos are too small to be of much use some to the point that they will fall out of the mortise if it is tipped up vertically. The 10mm also are under sized.
So my question for those of you who use the 8mm and 10mm dominos is, are your dominos in this size range as badly sized as mine or should I send these back in the hope of getting a more accuate batch in return?

These dominos were sealed in plastic bags so moisture loss should not be a factor.

Thanks
Gerry

 

[chrisrosenb]

I have used a large amount of dominos, but I never found a need to measure them.
After all, they are made of wood & as we all know, the size of wood will change with the weather or location.
It is not something I would be concerned about.

Chris

 

[Oldwood]

Thanks for the response Chris,

I had no reason to measure them either until I noticed the sloppy fit of the 8 & 10mm dominos.
I believe that without a good interference fit between mortise and tenon the joint will not be sound and that does concern me. I have made my own dominos and have no problem making them fit properly . What I am trying to ascertain is weather it would be worth my time to send these back. If I will get back dominos with the same variance that these have then I will use the ones that are within tolerance and make my own in the future. I have not had any problems with the 5 & 6mm dominos. As we all know making the joint is not that big a trick but making a joint that fits well enough to supply good wood to wood contact for gluing purposes is a bit more complicated.

Gerry

 

[tbellemare]

Gerry:

It seems odd to me that your Dominos would be loose in the mortise. The opposite is the norm. Are you in an extended super low humidity condition?

Tom

 

[Oldwood]

Thanks for the response Tom,

Yes I am in southern Alberta and it gets very dry in the winter months. I had just opened the bag of dominos and so I thought that would not be the issue here. Also the bags of 5 & 6mm dominos have been open for over a month and they still fit fine. Also only about 30% of the 8 & 10mm size are too small so do only some of them shrink do to loss of moisture? So do all your 8 & 10mm dominos fit tight in the mortise? I think a tight fit is quite preferable except in thin particle board stock which has a tendency to delaminate with very little force.

Gerry

 

[peter halle]

Gerry,

How about a possibly stupid experiment.  How about taking some of your undersized dominos and brushing them with water  or dunking them in a glass of water and then taking them out and letting them sit overnight.  If they then fit snuggly then you may have a solution.  If they don't then you know you have a problem and you can take the steps to address it.  The dominos are made of solid wood, and we all know that each board has a different moisture content and characteristics, I suspect that domi's might also.

Peter

 

[Oldwood]

Hi Peter,
Thanks for the response. I think i could soak the ones that are too small until they fit more snugly I just don't see that as a reasonable way to resolve the problem . I can mill them myself to the proper spec much more quickly and accurately. I think woods of a particular species tend to change dimension with loss or gain of moisture at a given % of size. My chart indicates that beech will change dimension.0019" for radial or quartersawn and .0043" for tangential or flatsawn per 1% of moisture loss or gain in 1" thickness. It seems that most of the dominos are quartersawn and that makes good sense when you consider the dimension change is less than half of what flatsawn is. I have two dominos in front of me the one that is too small is quartersawn the other is dead on 8mm but seems quite flatsawn so if the science works it should get larger or smaller than the other with gain or loss of moisture. Into the water bucket with them, I will keep you posted. I have a moisture meter but it will not read under 5% so I don't know where the dominos are now other than they are below 5%.

I still have had no one say that all their dominos fit or the contrary. I think the dimension change on a piece of .315" quatersawn beech due to moisture loss should not be an issue if they are milled from 6% material and then sealed in plastic bags.

Gerry

 

[JJ Wavra]

oldwood,

I find interesting that your dominoes are loose.  From your measurements you have about 1/128 of inch of play.  I have to admit that I would love to have that kind of play in my dominoes.  I purchased mine not long after they came out and I have to keep a set of dominoes for dry fitting that are sanded down because once they are in they are very hard to get out.  I regularly when making grooves for mating pieces add in .4mm with the router and have found this to be great.  Maybe more folks will chime in, but I think my dominoes are far too tight and would love, and I think they, need to have a little play in order to have modern glues work the way they should.

JJ

 

[sw1211]

oldwood,

I find interesting that your dominoes are loose.  From your measurements you have about 1/128 of inch of play.  I have to admit that I would love to have that kind of play in my dominoes.  I purchased mine not long after they came out and I have to keep a set of dominoes for dry fitting that are sanded down because once they are in they are very hard to get out.  I regularly when making grooves for mating pieces add in .4mm with the router and have found this to be great.  Maybe more folks will chime in, but I think my dominoes are far too tight and would love, and I think they, need to have a little play in order to have modern glues work the way they should.

JJ

Have you tried microwaving your dominoes when you're ready to use them, microwave thread

 

[Alex2]

I have the multi domino box and also 4 "shoe boxes" filled with thousands of dominos.. Some are on my shelves for the last 2 years with bags opened.. 90% of the time I'll have to squeeze those in.. they re so tight.. I never had one that was loose after doing a proper mortise... And humidity level in shop has been once or twice down to 20%...

Cheers,

Alex

 

[Oldwood]

Hi Alex,

I live in southern Alberta and use gas to heat my shop in the winter. It does get very dry here indoors do to the heating. It seems that my problem is the opposite of the norm. That is why I asked the question on the forum to see if anyone had dominos that were too small as I had only heard of them being to tight. I don't know why the ones I have are small instead of tight but all the mortises are the same same size and some dominos fit and some don't. When i cut mortise and tenon joints (I have cut a lot of them in the last 25 years or so) I find that the dimension of the mortise plus about .003" works the best. I will admit this is not a tolerance that is easy to achieve but I believe it is the one that works best.

Thanks for taking the time to respond,

Gerry

 

[JJ Wavra]

oldwood,

I find interesting that your dominoes are loose.  From your measurements you have about 1/128 of inch of play.  I have to admit that I would love to have that kind of play in my dominoes.  I purchased mine not long after they came out and I have to keep a set of dominoes for dry fitting that are sanded down because once they are in they are very hard to get out.  I regularly when making grooves for mating pieces add in .4mm with the router and have found this to be great.  Maybe more folks will chime in, but I think my dominoes are far too tight and would love, and I think they, need to have a little play in order to have modern glues work the way they should.

JJ

Have you tried microwaving your dominoes when you're ready to use them, microwave thread

I have not tried that yet.  I am going to give it a try eventually it is just another step that I usually forget to try.  Also,  seeing that I forget to microwave my lunch it is not a surprise that I haven't remembered this trick. [unsure]

 

[woodshopdemos]

Don't forget the other half of the equation -- the drill bits. they may be slightly oversized. My take is that you have probably a better glue fit than those with really tight Dominos. In all the times I have used DOminos, the fit has been firm and I doubt that they were able to keep glue in place.
  I got a set of the CMT bits knowing that they make theirs slightly undersized for the glue line.

 

[bonesbr549]

When I bought my domino, I experienced a problem similar to yours.  Some of the joints were tight and some were loose.  I did not think to put a caliper to the domino's.  I assumed it was my  technique not the tool.  I was using it like I did my biscuit joiner.  I just pushed it in.  I thought to myself, am I wiggling the bit by chance and therefore widening the hole since not all were bad.  I adjusted my technique, and went more slowly and methodically and never had the problem again.  I also put my pressure on the plate not the rear of the motor, that helps keep it square to the face. Just a thought. 

 

[Alex2]

Here in Montreal, can be pretty cold too

Sometimes, I will make the 1st 'pass' while applying pressure on the plate (dito) and going at a normal pace.. Then, I'll make a 2nd pass just to be sure that my mortise will be perfect. I find that it helps squeeze the domino in.

Now, if the mortise is too big for the domino it can be :

-faulty dominos (would surprise me)
-dried out dominos
-wobbling bit
-operator error

Now maybe you could exchange that box and see if the same thing happens with another one.. If new dominos are ok, then you got yourself a bad batch of dried dominos !

Cheers

Alex

 

[Oldwood]

Thanks Guys for your input,

Woodshopdemos,
I know what you mean I think a M&T joint that is too tight is hard to keep glue on the cheeks during assembly. I like to glue both surfaces prior to assembly and chamfer the end of the tenon. I find the CMT bits interesting but have not ordered any yet. (waiting for feedback from those who have tried them)

Bonesbr,
I think this may be part of my problem. I have used the 6mm cutter quite a bit and did not have a problem with it but when I started using the 8mm cutter I noticed the mortise is slightly larger in the solid stock then it is in particle board. I slowed down the feed rate in the solid and this does help some.

Alex,

What you guys don't get any cold weather out there do you ;~)
You said
"Now, if the mortise is too big for the domino it can be :

-faulty dominos (would surprise me)
-dried out dominos
-wobbling bit
-operator error"
I think you missed one......all of the above! As is often the case I don't think it is just one thing causing my problem but a combination of factors.

Thanks again to all of you,
Gerry

 

[Shutterstile]

I've had the same variation in the size of the 10 mm Dominos. Most in the last large bag of Sipos I bought were too small. It's not a problem with technique as I also make my own and they fit perfectly every time. It's also not a problem with humidity, as both the Festool Dominos and my own homemade versions sit side-by-side in my shop. The homemade ones are always a good snug fit while most of the Festool one's are loose.

I've just given up on Festool Dominos. It's so easy to make my own, that it just isn't worth it to spend 30 cents apiece for their's, when I know I'm going to have to throw half of them away.

 

[Tezzer]

I have never had a problem with them except for the 5mm Dominos. They are too wide. Not just one or two, but everyone of them. The little ridge on the side from machining stops them going in. How come Festool has never addressed this? Its so frustrating as I mainly use both the 8mm and 5mm.  [crying]

 

[Oldwood]

I am getting quite quick at running off a bucket of dominos, and they are the size I want them to be. I do find that in the very dense hardwoods if you plunge too fast the mortise will be over size.

Gerry

 

[Warrior]

I have found a super quick and easy solution to the overly tight fit on most of the dominoes I have used. I used to sand them...too much time and inaccurate. I then made my own....not a bad solution.

I recently purchased a HNT Gordan Gidgee smoothing plane to help with some curly maple pieces I am working on. The blade pitch is 60 deg and the mouth is so tight. Its an amazing little plane and I was getting 9 foot long thinner than tissue paper curlies with it last night.

perfect for pulling the domino over the blade with the plane upside down in my hand. Literaly, in 2 seconds I had overly tight fitting dominos fitting perfectly.