Joining advice....

[jim123]

Evening all,

I'm making a refectory table out of some old joists and am looking at different methods to join the table top lengths together. I'm not squaring the sides up so biscuiting and glueing won't be an option (I'm looking at a rustic finish instead of a nice clean and square 'oak furniture land' look). So far, I'm considering drilling through and pulling the joists together with some threaded bar but I'm looking for any other ideas that may work. The joists are 75mm x 175mm x 2300mm.

Cheers in advance!

 

[cusimar9]

How far from straight are the edges? I glued up a workbench (see sig) from old beams and though the join isn't perfect it's holding up perfectly well. If there are lots of big gaps >2mm then this won't work but you may be surprised.

If not, can you hold them together from underneath with a strip of wood either end spanning all the joists? Combined with glue this may suffice

 

[Jacob]

A trad way with heavy tables was to join boards with loose tongues drawbored through. This would leave a pattern of dowels on the surface which can be attractive. You can just see them on this Thompson top:

Threaded bar for really heavy tables! The holes can be square morticed or drilled well over size, except for the outer ones which have the nuts and washers, which makes getting them aligned a lot easier.

 

[jim123]

Cheers.
I did think about a joining strip but because they are about 3" thick I've got to be careful about how low it starts sitting before you can't get you legs under. Also, ideally, it needs to be detachable as the table top alone weighs a ton.
I suppose I could router out underneath for a strip to fit under and make it part of the uprights. Now we're talking.....!

 

[cusimar9]

Cheers.
I did think about a joining strip but because they are about 3" thick I've got to be careful about how low it starts sitting before you can't get you legs under. Also, ideally, it needs to be detachable as the table top alone weighs a ton.
I suppose I could router out underneath for a strip to fit under and make it part of the uprights. Now we're talking.....!

That's a point you could also use kitchen worktop bolts

 

[Mar_mite]

You could use short lengths of threaded rod and epoxy resin. Simply drill holes slightly bigger than your rod, say 4" deep, cut the bar at just under 8", a few squirts in each hole and push it together.

 

[Jacob]

.....
I suppose I could router out underneath for a strip to fit under and make it part of the uprights. Now we're talking.....!

A trad way of doing that is to make your "strips" like ledges on a ledge/battened door but to taper them and dovetail house them so they lock the whole thing together. This is common in France for shutters because a slim profile is handy. I couldn't see any pictures by googling but they are there somewhere.

 

[paulm]

.....
I suppose I could router out underneath for a strip to fit under and make it part of the uprights. Now we're talking.....!

A trad way of doing that is to make your "strips" like ledges on a ledge/battened door but to taper them and dovetail house them so they lock the whole thing together. This is common in France for shutters because a slim profile is handy. I couldn't see any pictures by googling but they are there somewhere.

Like the sound of that, using the materials themselves and less or no need for special fittings, glues etc, keeping it simple but effective

Cheers, Paul

 

[AndyT]

Have you designed the framework that will hold this top yet?
When you say 'refectory table' I think of something with some fairly chunky cross members under the top. Could you not just use screws, up through these, into each plank? (You'd need slots or just oversized holes to allow for seasonal movement.)
It would have the added advantage that your heavy boards could be handled individually even after the table was finished.