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basser425
18th December 2008, 12:18 AM
I am soon to get a walnut crotch slab, about 2" thick and 4-5' long. I want to use it as a coffee table in its natural state (sanded and sealed). My question is about the legs. what ideas might you have to support the beast? I can get extra walnut or other hardwoods to use, but have no idea what design to use or how to build the legs.
Thanks
Andy

mongrell
18th December 2008, 07:43 AM
natural edge slabs need natural edge legs not machined edges . get some more walnnut and maybe a base similar to trestle table ,quiet a few ways you can go just needs to match the top to the bottom

Peter36
18th December 2008, 10:09 AM
A support built from some of the branches in the style of chairs etc made from driftwood could look good . Definitely not fully machined legs .While you are thinking about it , I could let you have a few bricks :U:U

Peter

joe greiner
19th December 2008, 12:15 AM
What they said. But also add crosswise support at each end. Timber is notoriously weak in cross-grain bending, and without such support the table will find an early demise.:oo:

Joe

Miranda
25th December 2008, 07:36 AM
Do not use timber. Very weak. I agree Peter, that would look good.

simon d
1st January 2009, 03:51 PM
What joe griener said is correct but you need to fix the cross support in such a way that the top can expand and shrink. Typically you can use milled timber for this bit and then insert your au natural legs through it like those old quaker stools have their legs put on. That is a round hole which you put your leg through and then wedges in the top of the legs to hold them in place. Then screw the resulting frame to the underside of your slab.
The frame should be a flat rectangular affair like a basic picture frame (say 2" by 4" timber at least) with the corners lap mitred. Ive seen one with the corners full lapped and drilled out to take the legs as described above but you have to be careful to drive the wedges so the top of the lap isn't split and they don't look as good as lapped mitres. You then drill holes in the frame that are larger than your screw shanks and use domed screws and wide washers not countersinks. This way the screws can be done up tight to keep the slab from cupping or twisting but they can still slide sideways in the holes to allow your slab shrinking and expanding to go on unhindered.
A square frame will resist twisting better than two strips at either end and the larger the timber the better it'll be at keeping shape. If you make the frame about 100mm smaller all round than the top edges you won't be able to see it when your sitting at it. And you'll find also, I reckon anyway, that this element of milled timber with arrised edges will balance the natural elements nicely, if you happen to find yourself sprawled out and hungover on the carpet under it.
What ever you do don't try and do anything with the slab until it's properly dry and if you can, dry it at the bottom of a big pile of other timber. Usually in a cool dry and dark place, its about six months to one year for every inch of thickness but with moving air you can bring that down considerably. Another good idea for fruit and nut wood is to soak the slab in a water bath for about a month before you dry it. (I use a rough timber frame to support heavy duty concreter's plastic and a load of bricks on the slab) You change the water every week and that way all the resins in the timber are evened out from the sap wood to the core. I know an old woodie who ties his wood in bundles to a tree and then throws it into a running creek, that gives the best results. This process greatly reduces the risk of the slab splitting from uneven drying caused by different levels of resins in the layers of the wood.
good luck.