Wood-fired!

Foiling the dent fairies

June 24th, 2008

So you’ve just finished final sanding and cleanup and you’re ready to apply the finish. You turn the piece over and there is a dent in the surface that wasn’t there a minute ago. You check your bench for stray chips but it’s all clean. You blame the dent fairies and wonder if it can be sanded out.

This is an old trick for recovering without extensive planing or sanding. Many will know it but it’s here for those readers who don’t.

First wet the area with a small pool of water. I usually use spit for this as little water is required for a small dent and spit is usually on hand. You can let this sit for a short while if you’re not in a hurry. The moisture will start to swell the wood fibres where they have been compressed by the fairy’s little hammer. Sometimes with very small dents (and in softer woods) this may be enough for the fibres to swell back into place.

Usually though a little heat is required. This should be enough heat to locally boil the water but not enough to colour the wood. The steam swells the fibres very quickly and the wood expands back to the original surface. The usual method is to use a warm iron for this. A piece of plain paper is placed between the wood and the iron to prevent local over-heating.

I used a soldering iron in this case because it was readily available. (Still haven’t gotten around to adding an iron to my tool chest.) I simply stroke the side of the soldering iron tip across the immediate area of the dent until the water has evaporated.

Wetting and heating can be repeated a number of times if the fibres do not fully recover.

Once the wood is dry re-sand to restore your original finish. (The water will of course raise the grain a little.)

The process is shown for a small (real) dent but the technique works well for quite sizable dents (such as when the fairies swing large sash cramps around with insufficient care).

Try to recover dents as soon as possible after the event. Of course it’s best to keep the dent fairies away in the first place but that trick is for another post.

Entry Filed under: Wood