butcher block

[charlie spencer]

I made an end grain cutting board out of 8/4 walnut and quartersawn red oak. It clamped up beautifully with moderate pressure and I planed it dead flat.
Now it is bowed about 1/4" and is barely usable. It has not been submerged.
I finished it with 2 coats of mineral oil and 1 coat of mineral oil with 25% beeswax.
Any thoughts about this thing being unstable?

[Bill Houghton]

Did you finish top and bottom equally?

[Nate Carey]

The very dissimilar wood types are causing the trouble. The red oak is gaining and loosing moisture at twice the rate of the walnut.

[Corey Wilcox]

I made an end grain cutting board out of 8/4 walnut and quartersawn red oak. It clamped up beautifully with moderate pressure and I planed it dead flat.
Now it is bowed about 1/4" and is barely usable. It has not been submerged.
I finished it with 2 coats of mineral oil and 1 coat of mineral oil with 25% beeswax.
Any thoughts about this thing being unstable?

Charlie,

I make a lot of end grain cutting boards (some with a single species and some with multiple different species) and even after they're finished they'll warp if I lay them flat on the counter. If they do warp I just flip them over and the warp moves the other direction. If I leave them standing on an edge they don't warp at all. If you want to stop it from warping I would recommend putting feet under the bottom to allow air to circulate around all sides.

[David Keller NC]

One thing to realize about red oak is that it is ring-porous (i.e., you can blow air through a straight-grained piece like a soda straw). That means it isn't the best material for an end-grain cutting board, as meat juices will flow right through it (and saturate it).

This may be contributing to the stability problem you mentioned - oak's already a relatively unstable wood, and in the end-grain orientation capillary action will pull moisture right through it, so big chages in moisture content are inevitable.

[charlie spencer]

you nailed it . meat juice will penetrate 1 1/2 " in seconds . thanks

[Peter Quinn]

Beyond instability you have chosen two species with a distinct "flavor" and aroma, neither of which I would care to impart to my food. Hard maple is a traditional choice for a variety of reasons, one of which is its relatively neutral flavor. Food for thought.

[Howard Acheson]

Neither walnut or particularly red oak are good choices for end grain cutting boards. Walnut is pretty soft so is easily damaged by cutting tools. The red oak however acts like a straw. You can actually blow through the end and see the bubbles of air come out the other end if you put it into a glass of water. Before smoking was thought to be bad, we would demostrate how to tell the difference between red oak and white oak by blowing cigarette smoke through a five foot board. Because of this property, red oak will allow juices to penetrate deeply and cause rotting food odors and contamination.

All that said, without seeing a picture of how you constructed your board, we would all be guessing as to the cause of the warpage. It could be a number of things from dissimilar woods to improper grain orientation. Post a picture so we can see how it is constructed.

[Kyle Iwamoto]

Did you finish the board?
I made a board with maple/walnut and put a long grain red oak frame. The oak is definetly porous, but since my frame is side grain, that may not matter too much. No end grain shows.
I'd run it through a drum sander and then finish it with butcher block oil or something like that. That may seal the red oak. But I actually have no idea if that will work.

[Bill Huber]

Did you finish the board?
I made a board with maple/walnut and put a long grain red oak frame. The oak is definetly porous, but since my frame is side grain, that may not matter too much. No end grain shows.
I'd run it through a drum sander and then finish it with butcher block oil or something like that. That may seal the red oak. But I actually have no idea if that will work.

When talking about an end grain board the top and the bottom of the board is all end grain. The long grain is on the sides.

[David Keller NC]

I'd run it through a drum sander and then finish it with butcher block oil or something like that. That may seal the red oak. But I actually have no idea if that will work.

If you want to seal the pores, "butcher block oil" will definitely not work. BBO is mineral oil, which is a non-drying type (i.e., it doesn't harden). If you want to seal the pores, you can thin out a solution of shellac to about a 1 lb. cut and soak it into both sides of the board. Allow this to dry, and repeat a few times. Eventually the shellac will close up the pores of the oak. If you want the result to be a bit more water-proof, you can follow this up with a thinned alkyd varnish mixture (thin it with mineral spirits). Once the finish cures, it is food safe, and will impart a degree of water resistance to the cutting board.

[Pat Germain]

FYI, you don't really need to buy the stuff labelled "Butcher Block Oil". You can buy food-safe mineral oil at the drug store for a much lower price. The stuff labelled Butcher Block Oil is the same thing at a higher price.

Whether you use oil or varnish is a personal preference thing.

[Howard Acheson]

>> Once the finish cures, it is food safe, and will impart a degree of water resistance to the cutting board.

The water resistance will be compromized with the first knife cut. That's the reason film type finishes are not used on boards that will be used for cutting or chopping.

I would just turn it into a hot pad and not use it for food preparation. Red oak is just a very poor choice for a cutting board. There is a reason why close pored woods are used for cutting boards and chopping blocks.

[Bill White]

Fire wood I guess.
No red oak on any food surface.
Bill