Bed bolts to join slab table halves?

[Joe Craven]

Good evening everyone,

I lurk around here a bit but don't post too much. On this project, though, I'm trying to be extra careful so I figured I would reach out for some help!

I have a couple of chestnut slabs that I've been working on to make a dining room table. A 2" planing bit and 1 torsion box later, I finally have the planks planed on both sides (thanks for the collective help on this site getting me this far, BTW).

Anyway, I was thinking about doing basic tongue-and-groove joints to marry the planks, but because of the limited size of the planks, and because I want some character in leaving a big hole in the middle of the table, where the planks will join (on each edge of the table) I don't have too much overlap so I'm afraid that I won't have enough surface area - especially if I ever have to put this thing on a moving truck.

That got me to thinking: maybe I can just flush-cut both joints, and use bed bolts on the underside to marry the two halves? That way if/when I move, I can disassemble the whole thing with a little more confidence that it would survive the trip. I'm mainly curious if the bed bolts will stay tight enough over time, so that I'm not under there tightening them every couple of months?

Below are some pictures - the first is where they'll overlap and the second reveals what's left of the other (uncut) slab, in case I still want to go the tongue-and-groove route. Also, I plan to hire a welder to build a 1.5-2" square tube frame for the legs, etc., which I will affix to the underside of the joined slabs after dado-ing some grooves to inset a span of the metal all the way across the underside, on each end of the table (the point I'm making is that I should have plenty of stability there).

Many thanks,
Joe

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[johnny means]

The first thing I would consider is if the two halves even need joining. Depending on your base design, it may be feasible to just attach both plans to the top. If I had to join the two, I would use countertop bolts.

[Casey kerner]

I used my festool domino to join mine with tightbond 3 glue.

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[Casey kerner]

Figured I could post a pic of the legs I used too. Be sure to allow for expansion/contraction when you attach the legs.

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[Brian Holcombe]

You may want to consider making a system of battens.

[Joe Craven]

Johnny - wasn't even aware of such a thing (countertop bolts). I like that option much better, especially so I don't have to burrow out too much of one of the undersides, to get a bolt through to the other side. I'm going to order a handful of those even if I don't end up using them for this project.

Casey - beautiful table and thanks for the pic of the legs! I don't do any metal work (well, except what I can hack up w/ a Dremel tool) so I will probably play around for a while in SketchUp to try to come up with something sturdy and attractive before I go visit a pro to do the work. I'll make sure to leave some room for movement. And, I was thinking about biscuit jointing for the alignment factor alone...my buddy has one that I can borrow and he swears by it.

Brian - Battens: hadn't thought of that but I will definitely consider before finalizing the plans.

I'm now leaning to toss the idea of the tongue-and-groove approach, and go w/ (dry) biscuit jointing for alignment, and the countertop bolts to keep them together.

Now to figure out the order of operations for finishing and filling in a couple of the cracks w/ resin. I'm sure I'll be posting again soon!

Thanks y'all, for the help. I'll post pictures when I'm done! (this is kind of my first major project using non big-box/dimensional lumber, aside from a solid walnut platform bed and nightstands)

[Dan Rude]

I tried posting last night, but had issues with the site. Fastcap makes a surface mount for its countertop bolts called Flip bolts. It is a surface mount called a J-hook. This might work if you have thinner boards. Dan

[Dell Littlefield]

Would dry biscuits expand inside to the slots enough to cause problems in separating for moves?

[Jim Matthews]

My mentor just installed a large countertop using both the bolts you've considered
and battens that I recommended.

When using the bolts, you might want to also use cauls to keep things flat during assembly.
The bolts twist as they close, and that can lead to misalignments.

The battens are fixed to your legs, and the top should be held with either small clips or brackets
to allow for seasonal expansion across the grain.

This is a fairly thick timber, so it will generated substantial outward force on any permanent fixture.
(If bolted to the framework below, it can break things apart.)

[Kent A Bathurst]

I think you may be overdriving your headlights. Employ Occam's razor: The simplest solution is most likely to be the correct one.

1. If you need to disassemble to move, then you don't want to glue the halves together.
2. In the base plates, drill pairs of holes about 3" apart, sized exactly for the diameter of the screws you intend to use as fasteners. Clamp the halves together, drill the pilot holes, and fire the screws. These points are fixed. Expansion occurs from the center-line out, in both directions.
3. Farther away from the joint, put elongated holes in the base plate - which I am sure you intended to do for expansion. Drill pilot holes, fire the screws.

I see no value in any T&G joinery - the steel base plates will do a fine job of keeping the top surface/plane in line. Plane/joint the edges square - or even, if it was me, undercut them by 1* or so, so that the show joint pulls tight. Pull the assemble tight. Hold them in place with the center-line screws. Allow for expansion in both directions.