Domino joinery for frame/panel doors

[anwalt]

Hi everyone!

I'm planning to make some tall frame/panel doors for a wardrobe. The doors will be around 200cm tall and 60cm wide. I'm planning to make the rails and stiles out of 24mm x 70mm hardwood (oak) pieces, with one midrail.

I have a Domino DF500 -- not the XL -- and was wondering whether a couple of the largest dominos for this machine would be strong enough to join the rails and stiles.

I've heard that people wouldn't do this for external doors, say, and use the XL domino instead, which I don't have. But since the wardrobe doors are not as heavy as an external, can I get away with the normal size?

All the best, and thanks in advance!!

Ansgar

 

[mrFinpgh]

Will you be putting any kind of cope & stick profile on the doors?  What will your panel material be?

I would think you'll be fine with a couple 8mm dominos per corner, for a door that size.  Just be sure you can glue them up without twist.

If your panel material is anything veneered, gluing it will reinforce the whole structure and make for a reasonably strong assembly.

 

[Packard]

Is this a hinged door or a sliding door?

Hinged doors require much stronger joinery than sliding doors (including barn doors).

 

[Michael Kellough]

I took an old commercial cabinet door apart that was about 60cm wide. It only had a 10mm dowel for reinforcement in the 60mm rails and stiles so a large Domino in each joint should be fine.

 

[Lincoln]

Beef up your bottom rail a bit, if you can. Then you can get an extra domino in there, plus a bottom rail always looks smaller to the human eye if it's the same width as the other stiles and rails.

 

[Packard]

Does Festool publish any engineering data on joint strength using Dominoes?

I can’t find any online. 

If you come up with a new joinery method, I would think it is the obligation of the manufacturer (in this case, Festool) to publish that information.

It is like selling rope from a previously unused material and only identify it by the diameter of the rope and not publish the working strength and the yield strength. It would never be allowed to be used for anything but decorations.

Since the dominoes are expected to be used to create structural items, and not decorative items, that data should be available.

 

[luvmytoolz]

Does Festool publish any engineering data on joint strength using Dominoes?

I can’t find any online. 

If you come up with a new joinery method, I would think it is the obligation of the manufacturer (in this case, Festool) to publish that information.

It is like selling rope from a previously unused material and only identify it by the diameter of the rope and not publish the working strength and the yield strength. It would never be allowed to be used for anything but decorations.

Since the dominoes are expected to be used to create structural items, and not decorative items, that data should be available.

I actually don't see as that Festools responsibility, and also wouldn't see that as practical or realistic as most aspects of tools are very subjective. Things that can be quantified and stated/certified are things like noise levels, power consumption, in the case of extractors the particle rating etc as these are things that can be measured and must be provided.

However the various ways in which a tool can be used, along with the numerous adhesives, (or lack thereof), thrown in with the numerous grades of timber choices among and also within species, would render most subjective statements useless I think.

Then you also have the liability aspect which is even more cloudy, I've seen people use tools in very unsafe or silly ways, so if they don't achieve the stated parameters Festool publish for any given combination of glue/timber/tool, does that mean they can sue Festool?

A lot of woodworking is simply eyeballng stuff to see if proportions seem adequate for the intended requirements, and using centuries old knowledge in jointing.

 

[Packard]

That works for joinery methods that are historically acknowledged.

I will offer a parallel example.

If you go to a professional baseball game and a foul ball hits you, you cannot sue, because getting hit by foul balls are “acknowledged risks”.  That is, the process has been in the public eye for so long that the risk of getting hit by a foul ball is known to be a possibility.  Acknowledged risk.

Another example:  Bicycles are dangerous.  They can achieve significant speeds, and obstructions in the roadway are accidents begging to occur. But you can’t sue Schwin, because falling off bicycles is an acknowledged risk.

Back in 1970 or so, my brother-in-law designed one of the earlier versions of a recumbent bicycle.  He was set to produce them.  But he could not acquire liability insurance for these bicycles because they were so new that there was no acknowledged risk.  They would or could be held responsible for almost any type of accident.

So getting back to woodworking.  Nails, screws, tenons, dovetails, dowels, etc. have been around fo so long that there is an assumption of a vast body of experience to guide you in designing your joints.

But dominoes were brand new.  There did not exist a vast body of experience to guide you in their usage.  Festool should have published some data even if it were in the form of a disclaimer.

Disclaimer: Dominoes will likely fail in any joint you build.  Festool assumes no responsibility for such failures even if you execute the joints exactly per our instructions.

 

[luvmytoolz]

I'm pretty sure in the manual Festool do just that, they explicitly warranty the unit for faulty assembly or parts, but say usage is outside the scope.

 

[squall_line]

So getting back to woodworking.  Nails, screws, tenons, dovetails, dowels, etc. have been around fo so long that there is an assumption of a vast body of experience to guide you in designing your joints.

But dominoes were brand new.  There did not exist a vast body of experience to guide you in their usage.  Festool should have published some data even if it were in the form of a disclaimer.

Counterpoint - Floating / loose tenons existed before the Festool Domino existed; the machine as a concept/execution was new, but the joinery method itself was not.

Complementary point to the floating tenon existing before the Domino: mortise and tenon joints far pre-dated the development of any powered blade whether that blade was spun by water, steam, or electricity.  Circular and banded blades just made execution that much easier.

 

[Packard]

Counterpoint - Floating / loose tenons existed before the Festool Domino existed; the machine as a concept/execution was new, but the joinery method itself was not.

OK.  I can go along with that reasoning. 

The problem with the domino system, and DowelMax, is that there is no engineering data to fall back on.  They all depend on your personal experience.    But since I have never had dowels fail on me, how do I know the limitations?

I made a screen door a while back using a floating tenon system (Beadlock).  My door is just fine after 8 or 10 years of daily use. What I learned from that, was that it took too darned long to execute.  I switched to 1/2” x 2” dowels.  Much faster.  Nothing has failed, so I still don’t know if my “that looks strong enough” brand of engineering is on point.

As an experiment, I built a over-sized medicine cabinets using nothing but a Milwaukee brad nailer and glue.  In place for about 2 years and I fully expect it to last until I sell the house. 

I was skeptical about the strength of the medicine cabinet, but it felt quite sturdy.

Chairs need to be quite robust in construction, but yet I see restaurant chairs that were apparently shipped KD (flat pack, much like IKEA).  And yet those chairs seemed quite sturdy.

I want to build a floating pantry.  The alternatives are blocking the baseboard heat, or having a new baseboards installed.  (Over $10,000.00.). I have nightmares of floating cabinets separating from the wall because the joint fails. 

I read the original post with interest.  But since I use dowels (and beadlock) I’m still not sure how I will proceed.

 

[4nthony]

Counterpoint - Floating / loose tenons existed before the Festool Domino existed; the machine as a concept/execution was new, but the joinery method itself was not.

Agree with this, too. I had been typing up a similar reply last night and chose to get some sleep before finishing the post.

My post pointed to the Clamex P-14 as a new-ish joinery method -- though, I don't know how new it really is -- and as such, strength information is provided. Anyone can make a floating tenon in the shop from whatever wood they prefer. Few people can make a DIY Clamex and there isn't a vast body of experience to pull from.

Edit...

Interestingly, the Tenso connector (also, new-ish?) mentions "extremely high clamping force" but doesn't provide specific data.

I do not have any experience using them.

 

[peacefulandpatriotically]

while not the final say on this discussion, this FWW article has some useful information and comparisons on various joinery techniques.  Domino-based joints failed their tests with relatively little force when compared to alternatives, although we must look at these tests with a grain of salt as they are not 100% "real world" scenarios. 

 

[luvmytoolz]

The Tenso and Clamax connectors are not so great for load bearing uses IMHO, but for light load and knockdowns the Clamax are fantastic with a huge amount of pulling strength, and the Tenso for me are really designed for use in alignment, light loads, or used in conjunction with dowels/dominos, etc to provide clamping force while glue dries.

They're a fantastic compliment to the Domino in my eyes, extremely useful, and because of the shallower depth required make themselves useful in some scenarios the Festool connectors wouldn't be possible to use.

Having said that, the Clamax metal tab rides in a plastic slot in the mating connector and takes more than average force to break, but a little leverage on the Tenso and it will separate quite easily.

If I was building a bookcase for example, I would want to make a very shallow dado for the assemblies to slide in if I was using the Zeta, doesn't have to be more than a couple mm, but enough to simply stop the shearing forces from causing them to fail under load.

 

[squall_line]

You can glue tensos, significantly improving their pull resistance.

 

[Sparktrician]

If you're planning on mitered corners on the door frame, you might want to consider using lock dominoes at the corner joints to keep them together and resist the pull of gravity from doors being large.  This works well due to interfering angles of domino insertion.  The #3 dominoes in the message referenced are mortised in from door top and door bottom (for invisibility) and glued in place after the #1 and #2 dominoes are glued and the joint has been glued and clamped long enough for the glue to set up (overnight).  Any overage can be trimmed using a backsaw or block plane.  [smile]

 

[Lbob131]

Dominoes will likely fail in any joint you build.  Festool assumes no responsibility for such failures even if you execute the joints exactly per our instructions.

Thats  because  festool has  no responsibility  for joint  failure. Thats  lies  with  the carpenter imo.
If he  thinks  the  domino  will fail  then  don't use  it. Use  pegged  m and  t  instead.
And  what actually  would  fail?  The  actual  domino  or  the glue?
Dominoes  are  glorified  dowels  which have  been  used  for  centuries.

 

[ChuckM]

I look at Dominoes as glorified loose M&T joints, because dowels are stronger than Dominoes.

Since acquiring the DF500 almost a decade ago, I've built mostly with Dominoes or recently with finger joints unless the projects are hand-tool oriented. I haven't come across any Domino joint failure, but then neither have I over my entire life of woodworking. I don't build entrance or gate doors, but if I do, I wouldn't rule out the DF500 by default. I'd look at each door case by case to determine if it's the suitable tool.

Funny that the OP never came back to share his choice or result.

 

[luvmytoolz]

Dominoes will likely fail in any joint you build.  Festool assumes no responsibility for such failures even if you execute the joints exactly per our instructions.

Thats  because  festool has  no responsibility  for joint  failure. Thats  lies  with  the carpenter imo.
If he  thinks  the  domino  will fail  then  don't use  it. Use  pegged  m and  t  instead.
And  what actually  would  fail?  The  actual  domino  or  the glue?
Dominoes  are  glorified  dowels  which have  been  used  for  centuries.

I would add that if the Dominos fail, then the rest of the joinery will likely fail as well, as clearly the simple assembly techniques regarding gluing woods hasn't been followed adequately.

Unless of course for some reason the Dominos themselves aren't glued in, which apart from breadboard ends which is a special case, I can't think of any logical reason why they wouldn't be glued in to take advantage of all the extra surface area. Especially as they'd be exposed to glue from the mating panel edges anyway.