Thread: Bought dried silky oak and its seeping sap!

I don't think it has anything to do with the amount of moisture in the timber. Sap is a big problem with some timber. Not very familiar with silky oak but Northern NSW rosewood does it a lot. Might be the thinners in the poly that brings the sap to the surface.

Some people recommend drenching it with metho, but I am not sure of the exact method. I don't think you will get much sympathy from the timber merchant.

Sorry I can't be of greater help. Timberbits.

Originally Posted by timberbits

I don't think it has anything to do with the amount of moisture in the timber. Sap is a big problem with some timber. Not very familiar with silky oak but Northern NSW rosewood does it a lot. Might be the thinners in the poly that brings the sap to the surface.

Some people recommend drenching it with metho, but I am not sure of the exact method. I don't think you will get much sympathy from the timber merchant.

Sorry I can't be of greater help. Timberbits.

Thanks mate. I don't think silky is one of those gumy timbers. I've used silky a bit and have never seen this before, which is why I was thinking it was a moisture problem. Maybe I'm wrong??

Is a blimmin gorgeous looking piece of timber though!!!

Cheers

I'm not expert on Silky, but I think you are certainly entitled to ask the question of the supplier and see what they say.

Keep us advised.

did you buy it as seasoned or just a rough swan slab?

i have sawn a fair bit of silky but have never seen it do this before. even green it doesn't seep sap.

ChocW, 120 x 180 is quite a nuggety piece unless it was kiln dried it may still be damp in the centre unless it had been on the rack for a couple of years. Like the others I have not seen this before and I have used a bit of Silky but it depends how it was dried. If it was sold to you as dry I would definatly be asking the supplier for some form of compensation. The metho thing is not worth doing I don't think, I tried it many years ago, just a waste of metho. What size pieces did you cut from it?

Originally Posted by Claw Hama

ChocW, 120 x 180 is quite a nuggety piece unless it was kiln dried it may still be damp in the centre unless it had been on the rack for a couple of years................

Just to back this up, I bought a lump of 200 x 200 Rose gum a few years ago which had been sitting in the yard for about 3 1/2 years. I then took it to get kiln dried and they put it through four full cycles of the kiln. When I docked the timber to length it still showed moisture in the centre.

Mick

Greg - I think what you have is not 'sap' - it's gum or keno, which is something hardwoods produce when injured or stressed in various ways. This has nothing to do with moisture content - you could dry the wood down to zero MC and it will still be there, then wick out when you apply finishes in suitable solvents. I've had similar experiences with SO - can't tell from pics if yours is Grevillea or Cardwellia, but both can do it.

The usual recommendation for this type of problem is to re-sand and seal with a shellac-based sealer, then recoat with your favourite varnish. Depending on how much of the stuff is in the wood, you may get away with simply sanding off & refinishing.

Cheers,

I think you may have used water based lac.Looks like bleeding to me

Originally Posted by pineforyou

I think you may have used water based lac.Looks like bleeding to me

Hey...nope that face of the board has had no (zero) finish applied.

Cheers

Originally Posted by journeyman Mick

Just to back this up, I bought a lump of 200 x 200 Rose gum a few years ago which had been sitting in the yard for about 3 1/2 years. I then took it to get kiln dried and they put it through four full cycles of the kiln. When I docked the timber to length it still showed moisture in the centre.

Mick

Yeah that's what I was thinking since it was so thick, but if it was a moisture issue the seller should have dried it properly before selling as dry timber. Anyways the seeping sap/gum/keno or whatever it was seems to have stopped coming up through the surfaces with the finish applied so am hoping all is good!!

Cheers

Originally Posted by IanW

Greg - I think what you have is not 'sap' - it's gum or keno, which is something hardwoods produce when injured or stressed in various ways. This has nothing to do with moisture content - you could dry the wood down to zero MC and it will still be there, then wick out when you apply finishes in suitable solvents. I've had similar experiences with SO - can't tell from pics if yours is Grevillea or Cardwellia, but both can do it.

The usual recommendation for this type of problem is to re-sand and seal with a shellac-based sealer, then recoat with your favourite varnish. Depending on how much of the stuff is in the wood, you may get away with simply sanding off & refinishing.

Cheers,

Thanks Ian. Very interesting. I just sanded it back and rubbed on a few more coats of wipe on poly. Have not had any more gum/keno seep through so hopefully all will be good!!!

Cheers

120mm thick will never really dry.
Kilning it will only case harden it and when re-sawn the newly expossed face of the timber will rapidly change moisture content and useually lead to bowing or cupping or both!

buy a cheapish moisture metre and test it vs, something you know to dry... same species.

That certainly wasn't cheap either. If you take it back they will put a metre in it and confirm that it was dry(ish) at least on the surface. and if it hasn't been cut up ( ) replace it becasue your unhappy... Ian W is on the mark with this one, i think.

Good Luck.

Interesting.
I have come across this phenomenon with NSO Northern silky oak. This is a timber that I handle quite a lot and only once recently I had a piece cut to 6mm thick which appeared entirely normal when cut but left on the bench it started to "weep" a dark brown "oil".
This has puzzled me ever since, until I read the previous comments.
I think IanW has the right idea. It is definitely not common, and I can only think it has something to do with a fault in the timber. eg the larger board had a bark inclusion where it might have been damaged in the past.

The answer is to have lots of timber!

John Elliott.

Originally Posted by John Elliott

...........The answer is to have lots of timber! ........

It's always the answer!

Actually, it's not, but it's interchangeable with the other answer: "have lots of tools and machinery"

Mick

Mick,
I knew you wouldn't let me have the last word!
Here's to you and all the timber in your paradise.
Best Wishes......John Elliott.