Problems with 3" oak

[Ian]

Hi

I needed a plank of 3" oak for a project and went down to the timber yard to pick it out.

The idea was to slice of the edge to get a more stable piece plus to show the oaks rays.

But I found there was quite a few shakes buried in the plank. I got what I needed for the job but there was quite a bit of waste in both time and wood, is there any way of avoiding this perhaps 2" oak?

Any help would be great

Ian

 

[Harbo]

I think you have been unlucky - all pieces of wood are different and there can be "surprises" when you work on it. A lot of factors could have caused the shakes?
All part of the "fun" of buying real wood?

I cut though a 4" block of sycamore which looked perfect on the outside - it was rotten in the middle.

Did you try to take it back for another piece?

Rod

 

[Ian]

Well at that stage it was pretty cut up as I just thought the next bit will be fine.

Just a bit of luck needed then. I did get enough for the job but that was at the cost of the full plank.

Cheers

Ian

 

[ondablade]

Hi Ian, i'm no expert, but have done a bit of digging on sourcing larger sections in oak as i have a project in mind requiring it.

As it gets thicker it seems it gets harder to kiln dry without causing splits/checks etc, so the risk of problems in thicker pieces presumably gets higher.

Going slowly (maybe even air drying at first) seems to be advisable to avoid creating the stresses that cause the cracking - letting the outside get too dry while the core is still quite wet.

What i found was that none of the several timber processors i spoke to over here (Ireland) could supply kiln dried oak of over 2in thickness. Other than that is the guys doing air dried oak beams and the like for construction work where splits etc are normal and desirable as a feature.

That's not to say it can't be done, or that there aren't specialists doing it, but it's probably quite a bit more time consuming and creates more waste than does drying thinner sections - with the result that the mainstream guys seem not so keen to go there.

Depending on your project lamination of thinner material may be an option, although in my own case i don't want joint lines.

I'd certainly be interested to hear of anybody with experience of sourcing thick kiln dried oak - presuming it's available...

 

[Ian]

Thanks for that Ian, I think in future I'll go for 2" or 2 1/2".

I had heard a while ago some woods were hard to kilin dry in 3" due to this - but was suprised when my supplier had 3" so I thought it would be ok.

I don't mind joining pieces together to get my width as I have used a slipmatch before as a feature.

Thanks for the info that clears it up quite a bit.

Ian

 

[Sgian Dubh]

I had heard a while ago some woods were hard to kilin dry in 3" due to this - Ian

European and American white oaks are notoriously refractory woods to dry, even when the boards are 2" thick or less. In large part it's related to the wood's structure where the prominent and often visually desirable appearance of the medulla create lines of weakness that radiate from the pith.

Tension that develops in the wood's shell during the initial drying phase relatively easily transfers into surface checking that follows the medulla. As the wood continues drying, and the intermediate zone and core dry and shrink, the initial surface checking frequently closes up again. However, the break in the wood is still there and it typically reveals itself when the wood is worked.

Thick oaks boards, eg, 3" and above, are even more susceptible to surface checking, often severe, than thinner material so it's not surprising that kiln operators may be reluctant to dry this thick material.

The weakness of the wood radially is one of several reasons why many oak species have been so heavily used in the past. Many oak species are relatively easily riven, even with wooden wedges in some cases; riving or cleaving cooperative wood is one way to get useful boards for building artefacts, furniture, boats, etc when perhaps metal saws are unreliable or rudimetary at best. Slainte.

 

[ondablade]

Don't be totally put off by what i found Ian, my experience is limited, and it's just possible that somebody will chime in with an option.

The sense i seemed to pick up was not so much that it can't be done - more that the mainstream producers don't want to get involved in work that requires babying or long drying schedules..

 

[Ironballs]

Nothing really to add to what Richard has said, in my experience when using thicker section oak it tends to be get the best you can through a visual inspection and then hope for the best when machining. I would say that with 3" oak and above then you have to expect shakes and cracks to some degree and build around/with it.

One thing I did see at British Hardwoods in Keighley (who kiln some of their own wood) is that for thick oak posts they will drill a hole down the middle to allow drying in the core. Won't work for every application, but if a hole in the middle won't cause you an issue then it may be worth giving them a call

 

[Sgian Dubh]

One thing I did see at British Hardwoods in Keighley (who kiln some of their own wood) is that for thick oak posts they will drill a hole down the middle to allow drying in the core.

Actually, the hole you describe isn't for that purpose, although it may let a little air in which could, to a limited extent, assist drying. It's there primarily so that the wood has somewhere to shrink as it dries therefore reducing the likelihood of surface checking. Slainte.

 

[RogerS]

I'd also add that in my experience there seems to be some duff oak (possibly imported from Eastern Europe) that hasn't been kiln-dried with any degree of 'sensitivity' for the oak....buying top quality should help.

 

[Richard Findley]

Hi Ian,

3" Oak is easy enough to get from my timber merchants (I use either Brooks Bros in Nottingham - used to be Fitchett & Wollacot - or James Latham) but the internal splits which you can't spot from outside are often a feature :evil: :evil: !! So your options are either buy more and waste more (which is no one's favourite option) or laminate from thinner stock which in some cases is fine but I have come across similar splits in 2" as well :evil: :evil: . You usually have to work on 50% waste with hardwoods anyway so keep that in mind too.

HTH

Richard