How to straighten red gum slab

[nicholas]

Hello Everyone
I have just joined this bulletin board and am hoping for some advice . I have a red gum slab that is approx 1.4 m wide by 3m long
and it is cupped across its depth(1.4m) by about 1.5 inches it also is cupped along its length (3.0m) in the other direction so if it was on the floor the ends would touch but the middle wouldn't but you could rock it back and forth.
So i was wondering what to do!
Would it be possible to wet it to remove the cupping?
I was also wondering about putting some weight on it as I have about 3000 pavers
sitting just outside the garage the slab is now in

Thanks in advance
Nick

[Neil]

G'day Nick

It is possible to get the cupping out by applying moisture to the concave side and heat to the convex side. This is easily done by laying the concave side down on wet grass and allowing the sun to warm the convex side.

However it really isn't worth the effort as it will only happen again. Red gum is notoriously unstable and moves all over the place. This is especially so in big slabs especially if they are over 40mm thick. The thicker they are the more unstable. If yours is around 30mm thick then it may be worth trying to flatten it as above if not leave it alone.

There is a story of a man who used thick slabs for his kitchen bench tops. In an all out effort to stop them from warping the whole structure was dyna-bolted to the cement slab. One night they heard an almighty explosion and upon investigating found that the whole thing had been ripped from the cement slab and half the kitchen cupboards along with part of the ceiling was destroyed.

Such is the force of this stuff. leave it to its own devices. Let it find its own shape then have it machined flat. Hopefully then the movement will have settled and it will stay put. But not necessarily.

Hope this helps.

Cheers - Neil

[This message has been edited by Neil (edited 19 June 2001).]

[nicholas]

Thanks for the advice neil much appreciated
The slab has been up on the horses since moday arvo and it looks a bit flatter all ready
wishfull thiking? or could it be obtaining
moisture content equilibrian

Nick

[fcm]

Question : Was it kiln dired ?
I've work with this stuff for a few years cut out of my property in east gippsland and if I've learnt one thing, it's never work furniture out of red gum that hasn't seen the inside of a kiln managed by someone who knows how to treat this stuff.
Criminals selling air dried redgum, especially slabs, might as well throw in the oars for free.

[JackoH]

Get a chain saw chop it into bowl blanks and spindle turning lengths and flog it to wood turners! (i'll buy some, at the right price)
John H.

[Iain]

Make a benchtop out of it and when you are done give me a call and I will get my wife to make you a batch of scones, nothing will move them........sorry love, it was only a joke, ouch, stop it please.