Distinguishing White from Red Oak?

[– Colonel –]

OK, I have quite a bit of mixed red and white oak that I bought, green, from a local sawmill several years ago.

I now have a need for some in a marine appplication where the wood will see a lot of water and UV. Red oak is out, but I'm having trouble telling which boards are white oak in my piles. I mean, on some pieces (especially among the ones that are obviously red oak), the difference is obvious -- but there is a fairly large percentage where I'm not sure whether it's red or white.

Does anyone have any good, easy, relaible ways to tell which is which?

Thank-you for any replies.

[Joe]

This is going to sound smart-alec but red oak is either reddish or whiteish. Usually, white oak is whiteish or reddish.....

Now that i've made you curse me for that response.... (which is true), here's a link. try the straw technique.

[Leon]

Cut a 1/8" piece off the end so that you can look through the end grain of the board. If you can see light through the end grain of blow air through the end grain you have red oak. If you cannot do either of the above it is white oak.

[DJ Delorie]

Get it wet. Red oak is pinkish when wet, white oak remains white-beige.

Also, they smell different when cut.

[B A R R Y]

If I have samples handy, I find it relatively easy if the boards have been surfaced.

Red oak is usually pinker, white is usually cream or beige. There is usually a difference in the texture, with with white harder, tighter, and slightly smoother.

The two woods also have significantly different smells when cut or planed.

The boards you get wrong will easily blend with the other species.

[DouginUtah]

Get some Sodium Nitrite - NaNO2 (5 or 10% solution) and put a drop on the wood. If it turns black it is white oak.

-Doug

[Doug Miller]

[...]

Odor when wet. White oak smells like vanilla and toast. Red oak smells like cat piss.

[Nova]

The cell structure of red oak is similar to a bundle of soda straws. You can blow through it. White oak has a closed cell structure. For those boards in question cut off a small piece and see if you can blow through the end grain.

[Phisherman]

Try to blow through a cross-sectional area--the red oak will allow air to pass through, the white oak will not. That's the reason red oak soaks up water and white oak will not rot. Of course the easiest method is by appearance, but be aware that white oak can take on more color variations than red oak.

[Leon]

If it is not white oak, it blows up?

[clare at snyder.on.ca]

I'm not 100% sure, but from my recollection: Drive a bare iron nail in the board, wet it and let it sit for a few days. In my experience red oak gets a nasty black stain and discolours the nail. White oak does not. Something to do with Tannin levels.

[Bob Meyer]

Put one end of a stick in water. Blow on the other. If you see bubbles, it's red. If not, it's white.