Grain Compression

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When you’re using your chisel to cut ramps, and holes, and so on, one of the problems you might get is grain compression. This is what happens when you try to chisel hardwood across its grain – and it makes something of a mess of the “end grain” which is left behind. The pic on the left shows a cut which has been the victim of grain compression;the gaps and roughness are where grain has separated and pressed together with other bits of grain. The pic on the right is a similar cut which has been done properly and shows none of the symptoms of grain compression.2015-09-19 14.40.57

To avoid this, you have to cut very gently and slowly across the grain; so line up the chisel to cut, and instead of giving it a good whack, like you would when you’re lined up with the grain, gently tap the chisel until it’s buried by a millimetre or so, then stop. Turn around now, so that your chisel is lined up straight INTO the end grain, roughly lined up with where you cut down to. Then cut inwards so that a small chunk is released at the top. Now repeat – cut downwards, then cut inwards. Keep doing that until you’ve got all the way to the
bottom of your cut. If you’ve been gentle enough then you should have a smooth end-grain which is pleasing to the eye, instead of the ragged end you see in the left-hand pic.

(By the way – all the ragged end you see in the pic was waste wood anyway so no harm, no foul in this case… and I cut it this way deliberately for this blog post)