How do I seal and/or waterproof Burnt Timber?

[Lis_n_Luke]

Hi there!

I am relatively new to woodworking, and would appreciate the thoughts of your learned members.... A friend's home was lost in Kinglake in the Feb 09 bushfire mess, and it's replacement is nearly finished. (yay!) I make water features, usually from metal found objects, but I have a gorgeous piece of salvaged timber, that I would like to make into a water sculpture for them. Most of it's surface is burnt or scorched, and this is the effect I want (Water running over the burnt surface to 'heal, renew, refresh' etc) So I am thinking of a poly type finish, but think these would only seal as a 'layer', and probably 'flake' the charring off eventually. Could I use an oil product to penetrate, then seal the whole thing over? Am I just being ridiculous? I would appreciate any thoughts! Thankyou, Lis

[Master Splinter]

Nothing is really going to sink in to any great degree unless you go to the extremes of treating it in a pressurised container to some sort of vacuum/several atmospheres pressure cycle. 'Penetrating' oils only really get in a few mm and aren't all that good at waterproofing anyway.

Best achievable suggestion would be to do what the wooden boat people do - a couple of coats of marine epoxy to seal and waterproof, followed by varnish over the epoxy to protect the epoxy from UV.

[Barrie Restall]

If you have some bits to run some tests on, try sealing/stabilising it with dilute Bondcrete before using a synthetic finish (marine varnish etc).

Cheers

Barrie