Slab benchtops

[shane cloak]

I have two red gum slabs with my name on them
in a wood sellers warehouse. but the horror stories keep coming ie; warping, spliting,
cupping. I wish to have "slabs of wood" as the benchtops in our new kitchen.
so my fellow woodies may I pick your brains for your opinions, as to what may be the most suitable timber to use? the benchtops will be approx
3.000mm x 670mm x 2 off.
The two red gum slabs on hold for me, are kiln dryed to a guaranteed 10%, does this mean that they would be any more stable than others?

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Cloakie

[woodboat]

Cloakie,
I cut slabs daily, Red Gum is one that gives the most trouble from green. A good rule of thumb is, 12months air drying for every inch of thickness. To kiln dry before a reasonable time of air drying means that the moisture doesn't release evenly from the slab. Timber should do most warping,splitting etc. before kiln drying.
Any fault will always become worse in a kiln. If you have been guaranteed a 10% moisture content, It is hard to see why it should keep moving.I would be a bit sus on that. Also, what part of the log did the slab come from? Look into the end of the slab (growth rings) and see how far away from the heart it is. The closer towards the centre of the log, the more unstable it will be. If it ain't right now, it probably won't get better. If they are slightly cupped, but finished moving, slabs can be dressed again on the faces. Anything dried to 10% should really be totally stable, I would of thought.
Hope this helps,
Cheers,
John.

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[ubeaut]

I'll bet you any money that they are not 10%. Try deep probe moisture metre and you will be lucky if they are even at 20%. A bit of humid weather would see the 10% KD wood back up to 18%+ in no time, the stuff is like a sponge. The only way to keep it at a low moisture content is keep it in a dehumidified room and that's one thing a kitchen will never be.

Your only part way reasonable option for redgum slab is to saw it into 3 or 4 planks let it do its thing then machine and plane the cut edges and glue it back together, then have it remilled to 25mm thickness or less. Either that or learn to live with the inherrant problems of this timber.

A poorely dried or air dried redgum slab could move that much that it can literally tear a kitchen apart trying to relieve the stresses within.

Appologies to John and other lovers of this timber, but as I have said before I am not a fan of this timber in kitchen benches or furniture. Leave it for fence posts, house stumps and turners that know no better. (sorry Doorstop) http://ubb.ubeaut.com.au/ubb/biggrin.gif

Hope this helps.

Cheers - Neil http://ubb.ubeaut.com.au/ubb/smile.gif

[Eastie]

The better slabs I've come across originate from trees dead for 50 plus years then kiln stabilised and then left to further stabilise, say 12 months (this time depends on who you ask and how many failures they are aware of after customer delivery).

Also, unlike other timbers, when selecting a redgum slab I would not look for the cleanest most highly feature slab - I would go for the one that has a balance of feature, cracks and natural through sections running along the trunk that can later be filled.
Similar to boarding the slab, natural cracks when large enough act as stress relief by breaking the slab up. As long as the slab isn't flimsy enough to snap apart the cracks can be filled with resin and the slab should be quite sound.

Another misconception is thicker slabs are better. Not generally so - they tend to develop more stress and go off with a bigger bang.

Finally, if it does fail and smash your kitchen to pieces (hopefully whilst you're not in the kitchen), through your tears and irrational thoughts should you think it possible to repair - cut it into boards and start again.

Also, choose your finish wisely. Some of the finishing experts would be beeter knowledged, however I recall some finishes being more "water tight" than others (if there can be such a thing in finishes).
A finish that hinders absorbtion/evaporation may help it keep shape & some finishing books touch on this - although there are a million variables.


I would also be happy to hear what others think about these wood working monsters.

Mark

[This message has been edited by Eastie (edited 11 February 2002).]