Butcher blocks can kill
There are many fascinating treatises online about the virtues of plastic versus wood cutting boards. In fact, the subject approaches the ever-enlightening “linux versus windows” debates for elucidating online reading.
But regardless what the self-proclaimed experts say, I decided to make a real, honest-to-goodness end-grain butcher-block cutting board. The idea behind the “end grain” thing is that you glue together a bunch of strips, let it dry, cut them into strips again, rotate them so the wood grain is pointing up towards you, then glue them up again. That’s why butcher blocks appear to be made of lots of small squares. The end grain is tougher, so it stands up to your knife better.
When I went on my spectacular wood buying adventure last weekend, my supplier had an oak glue-up laying around. It looked perfect–most of the work was already done; it had been cut into strips, glued up, and surfaced on both sides.
I brought it home, cut it the other way, and glued it up again. Then I noticed a problem. Up close, the oak looked like a packet of straws.
<--click for a closeup
It's like a water park for bacteria.
It turns out that oak is known for having open pores--very open pores. In fact, when I put some shellac on this in an attempt to seal it, the shellac literally soaked through the 1.75" thick board and dripped out the other side. Which gets us back to the plastic-versus-wood debate.
The debate hinges on whether plastic or wood is the best at harboring food particles, and hence bacteria. There are arguments for both sides. It seems pretty obvious to me, though, that oak is basically a big wooden sponge, and as such not exactly suitable for a sterile chopping block.
But still, what to do. I have this great cutting-board-shaped glueup that I hate to go to waste. So I try experimenting with a cutoff. Shellac didn't work, as you saw above. I decided to try something wacky. First, I spread a 50/50 mixture of Titebond II glue and water, and let it soak in a bit. Then I spread powdered pumice (yeah, the volcanic rock--they sell it at woodworking shops) all over the surface, working it into the nooks and crannies. I mixed it with a little denatured alcohol to get it in every crevasse. Then I repeated this again. Then I sanded it up to 220 grit. Check it out!
Pumice: it’s not just for Pompeiians any more.
I’m going to try finishing it with tung oil tomorrow. I’m making chicken next week, so if you see posts dated after that, the filling process worked and I don’t have salmonella. In the mean time, if you’re planning a butcher block, don’t make the same mistake I did. Just start with maple. You’ll thank me for it.
(Please, don’t try this at home…)
(pictures of the final block to follow if all goes well)
(interesting article I found after finishing this post–it’s a government(!) document describing different finish types: http://www.fpl.fs.fed.us/DOCUMNTS/finlines/knaeb98c.pdf)
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