Help with assembly question

[MavDog]

I am building this unit and have a question about the best way to assemble one of the joints. 
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On the cross supports which are 2.5" high and made from 3/4" thick oak I am trying to figure the strongest way to attach them to the vertical pieces which are made from 3" wide 1" thick oak.
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Since the cross supports will be supporting the shelves I would like to make them as strong as possible.  On the right side since there is a notch (for the front edge of the shelf) I only have room for a single 6mm domino and one pocket screw.  On the left side there is enough room for either two 6mm dominos and a pocket screw or two pocket screws and a 6mm domino.  It will be tight with two dominos and a pocket screw but I am thinking that would be the strongest way to attach them.  I will also be using glue. 

Your input would be greatly appreciated.  Thanks for looking.

 

[tjbnwi]

Dominos and glue, one and two as you figured. Use a 5/8" 18 ga. brad through face of the oak into the domino to lock everything together while it is in the clamps.

If I was going to use pocket screws, they would be through the bottom edge of the rail into the style.

Tom

 

[MavDog]

Thanks Tom.

Since these are something that will be transported, setup and taken down every weekend I wanted to use the pocket screws as a little extra insurance nothing would come apart.  I thought about using the screws in the way you metioned but had never seen it.  I will do it that way and use the oak plugs so that it looks nice.  On the notched side I can probably get two pocket screws by doing it that way.

 

[builderbob]

Hey Mav!  I think Tom has you covered as far as his recommendation. I'm curious what you'll be displaying in these. These are a neat idea...kinda like a shoji shelf...just curious!  Post completed pics when it's all put together!

Bob

 

[MavDog]

Hi Bob,

They will be for pottery.  The shelves will have LED underlighting and there are also some display boxes for the booth that will have onyx tiles with LED backlighting to make them glow.  I will post pictures once it is finished.

 

[semenza]

Those are pretty cool for a portable display , .................. or even a permanent display  [smile]

I agree that you would be fine with the Domino and glue.  I am not sure the pocket hole will add much  and , depending on exactly how it works out, could  end up interfering with the Domino strength.  I think that if the glued Domino starts to wiggle loose , then the screw  will be coming loose also, and either way will necessitate repair.    So just take the single hole Kreg jig with you in case you need to stick a pocket hole screw in for a temp. repair.

Seth

 

[MavDog]

So you guys think just the Domino and glue will be fine? 

This is not for me, it is a unit I am building for someone else.  I have used just Dominos and glue in the past and have never had one come apart but I was thinking since the pottery could be heavy the pocket hole screws would add a little extra support.  If you don't think they offer any benefit that make my assembly process much easier. 

 

[tjbnwi]

Yes, just the dominos will be fine. As I said, shoot a brad throug the face of the oak into the domino, as if you're pegging the tenon. 5/8" brads, one in each member.

You can make a joint "fastener weak".

Tom

 

[Kev]

Personally I'd be sinking the entire rail ~10mm into the upright ... but 3/4" into 1" doesn't make sense for that [unsure]

I'm not concerned about ongoing load, I'm concerned about "landing". If someone was to be a bit rough lowering a 15kg potted plant onto a shelf you may have an issue.

Maybe some nice flushed right angle metal brackets ?

Either way, I'd be making a test rig and drop the weight you'd worst expect from a few inches (imagine smacking one of those joints with a 4lb hammer).

Kev.

 

[tjbnwi]

There is the option of upping to an 8 mm domino on the "front" joint, 2 6’s in the rear joint. The vertical domino in shear will be very strong.

Tom

 

[MavDog]

That is a good idea Tom. No problem with the 8mm in 3/4 material right?

 

[tjbnwi]

The load on this is vertical, the 3/4 dimension is not carrying any load (unless someone hits it) 5 mm each side should be fine in oak. You could test a 10, I would, but then there isn't much I won't take a shot at.

Tom

 

[MavDog]

Thanks for all the help Tom. It is much appreciated. You just saved me a bunch of assembly time also

 

[tjbnwi]

Some day I might figure some of this stuff out.

One can hope

Tom

 

[Nick C]

I would use traditional mortise & tenon joinery for this. Probably 5/16 x 1-1/2, and as wide as practical. I would also peg or fox wedge the corners.

 

[hrrb]

Nice looking shelves!

I think I'd go for dominoes and glue or traditional mortise/tenons and glue for the cross bars in the "ladders".

And I'd put on some nice expensive looking brass hinges in the corners of the two "ladders". That would make transportation easier.

On the lower and upper cross bars I'd make some pegs/dowels fitting into holes in the shelves - just to make it more stable. Unless of course the shelves are made of glass!  [wink] Maybe even fixate the shelves with screws.

Kind regards
Henrik

 

[MavDog]

Thank you everyone for the help.  Here are some pictures of the completed units.  I ended up using 2 6mm dominos on one end and a 8mm on the other and glued and pinned them.  The units are very strong.  the customer was very happy with how they turned out.
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[aptpupil]

Looks great. Would like to see them once installed. Where do you plan on hiding the LED transformer?

 

[MavDog]

Thanks.  They are used for craft shows so they are not permanent.  All the transformers will be hidden in a back corner of the booth so you won't see them.  The wire from the shelves is neatly routed through holders on the back side of a unit so you won't see them.

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[semenza]

Those look very nice. Nice wire routing detail.

Seth