Domino Strengths

[USMCGRUNT]

Hello All,

I am building a chest (appx 40”W x 20”D x 25”H) for my daughter and had a few questions in regards to the joinery. I have used my Domino Jointer before with great success, however I am doing something a little different this time.

I am using 13/16 (final thickness) white oak for the actual box and attaching them to the slightly curved legs with dominoes. I can attach a picture of a test leg. The dominoes are spaced out about every 3” and was using the 8x50 and 40’s. I was originally using the 50’s until I realized that the depth would come through each side and hit each other on the curved legs.

So my questions are:

- What kind of weight will the dominoes hold? The front and back faces are about 20 pounds.

- Am I better using 50’s on the long faces and then 40’s for the sides  (25mm in side and 15mm in leg) or just using 40’s for both with about 3mm on the inside or the leg between front and side mortises?

- Was I wrong in making one “tight” mortise and the rest on the second “loose” ssettint in case of any misalignments or board errors? The manual said that was fine to do but I feel like it takes away strength.

I will attach a couple pics to clear this up if it doesn’t make sense.

Thanks!

 

[Birdhunter]

I do all tight on one board and all loose on the other board. I tap the two into perfect alignment with a dead blow hammer. I start aligning the boards when the Dominos just start in and though the mating process if there are a lot of Dominos. If you have a lot of Dominos and they are all the way in, it’s very hard to tap the boards into alignment.

I’d look at how seasonal wood movement might affect the chest. At first glance, it appears as if the chest sides would move enough to creat a problem.

 

[USMCGRUNT]

Thank you much for the reply, that definitely makes sense. And I hate to admit it, but I did not even take the movement into account. Do you think I’m going to have an issue putting the dominos in and completely gluing all 4 corners together? And is there a fix this far along?

 

[sancho57]

I think you'll be fine Sir.

Sons a 0311 with Kilo Co 3/5. Damn proud of him.

 

[USMCGRUNT]

The reassurance is much appreciate, haha.

And Semper Fi, you should be proud of him. You did well Dad! I was an 0341 a few moons ago. If you don’t know what that is, it’s someone who enlisted as an 0311 and was unfortunate enough to be picked when they went down the line calling numbers...Infantry Mortarman

 

[sancho57]

I am proud of him, I am a vietnam era vet, went into civil service DoD and did roughly 42 years before I retired. As a DoD civilian I did 3 tours of Iraq and 2 tours of Afg. I was stationed at the same FOB with the 3/5 Lima Co. on my last tour.

They were Bad ass Grunts loved them.

 

[Kodi Crescent]

If you're concerned about many loose fit pockets, I mark a line and plunge 1 or 2 mm on each side of the line.  The dominos go in straighter, slide in more easily, and I have just a bit of wiggle room to smack things into place to get my lengths flush.

 

[Shane Holland]

With regard to strength of the tenons, there are some videos on YouTube that are relatively in-depth tests. Here are some examples, plenty more if you're interested.

The results of this test were 238 lbs for the Domino.

 

[thudchkr]

In regards to the domino length, you’ll get a stronger joint with the longer domino. When I do something like this, I’ll miter the end of my tenon so they can meet inside the leg but still have the outside of the mortise full depth for gluing surface.

i use a small miter box and a hand saw to miter something small like a domino, but one could do it easily with a bandsaw of other power tool with appropriate jigging.

If you do this you’ll likely need to install your mitered dominos into the leg first otherwise you’d risk damaging the mitered ends of your dominos.

All in all, I doubt you’d have any strength issues with the shorter domino, but you’re good to use the 50’s this way, if you wish.

 

[Jesse Cloud]

I weight embarrassingly close to 300 pounds.  [eek]

I often stand on structures I have built with Dominoes, never had a problem.