Removable connection of 2 live edge slabs

[drbusch]

I have a set of 2" live edge ash slabs, cut with one flat face which together are app. 32"x6’. These have been air dried for several years outdoors (covered) and this summer in my non-climate controlled garage.
The goal is to make a picnic table which will be semi-exposed to the weather (little direct sun, rain).
The slabs are heavy enough that I don’t want to permanently attach the two pieces together, as this table will be moved.

My question is: “How to removably register the 2 slabs together?” (in the vertical (2") + in-plane axial (6’) and in-plane transfer (30") dimensions)

My current plan is to have metal legs supporting a frame on which the slabs will rest with over-sized holes in the frame for bolts to threaded inserts placed in each slab, permitting the wood to expand/contract.

I hope to use butterfly latches or similar to hold the slabs together at the seam (30" dimension). Alternately, I am considering recessing 3/4" metal angle along the 30" dimension with bolt into threaded inserts placed in the wood.

For the vertical + in-plane axial dimensions I am thinking of using large dowels without glue, permitting removal when the table was broken down for transport. To simplify removal and increase strength, I thought of using ‘dowels’ made of metal rod. The thermal expansion of the rods would be ~2x different from the wood, which may cause issues although it would be a less than 1%.

I’m struggling a bit on how to align ~1/2" holes for the dowels- they need to be normal to the slab-slab contacting surface. The longer the dowel pins are, the less error is permissible.

Any suggestions would be much appreciated.
Thanks
David

[mblatz]

If you indeed have a flat surface on each side of the two slabs intended to face up and want to be aligned on that plane, then that suggests you will want to use the Festool Domino joiner. Pretty easy to come up to speed on this tool, and additionally easy to use, in general. There are also folks around that use it that can offer help if needed.

Does the Domino require training?

No training required AFAIK, and tool wiki does not indicate any required, either. I find Festool instructional videos to be some of the most helpful in the industry (i.e straightforward, practical, and to-the point): [Getting Started with the Festool Domino XL DF 700 Joiner]

Additionally, look into/consider incorporating anchor bolts into design:

Domino Tenon Stock

Just one per rail end. I’ve done that on a queen bed in the past with success. Using 2 additional dominoes on each rail end glued into the rail for strength and support Very similar setup to this [image]

Note: it seems to me that over the years, after seasonal cycles of high heat/humidity and then the opposite, you will almost certainly run into challenges keeping the flat/“up” sides from showing a ridge where joined if the joint is not glued. This is akin to the impossibility of keep a piano stored outside in tune…just not gonna happen. But I guess it can always be covered by a table runner or whatever?

[drbusch]

@mblatz
I think the seam down the middle of the table will be much less of a challenge than moving the table in one piece- one half of the table is just about at my max weight+size limit to move.

The legs/support system has not yet been built.

I will take a careful look at the Domino Joiner.

Thanks