Article on Best Finishes to Prevent Wood Movement

The latest issue of Fine Woodworking (USA) had an article on the comparative effectiveness of different finishes to prevent wood movement. I hadn't seen these direct comparisons before and thought others may find it interesting. The following is a summary:

1. The most effective clear finishes are oil based polyurethane and shellac. Over a 14 day period they repelled 42-44% of moisture.

2. Linseed oil repelled 0% over the same period as did paste wax. Tung oil chipped in at 2%

3. NC lacquer was 19% and spar varnish 30%.

I guess good construction is still the best way to ensure wood movement doesn't cause problems, but the info may help some to decide which finish to use in problematic situations.

...or you could slather it in epoxy, which is second only to complete enclosure in paraffin wax. (6% weight gain after 8 weeks at 27 degrees C, 90% humidity).

http://www.westsystem.com/ss/moistur...effectiveness/

(yeah, yeah, I'm an epoxy fanboi)

2 Pack Epoxy as a fine furniture finish? :):?

Epoxy wasn't tested, presumably because the magazine was focussing on more commonly applied finishes.

The interesting thing for me is that Linseed oil, tung oil and presumably other oil finishes are not very effective compared to to shellac and varnish

As a matter of interest, there is a more comprehensive table prepared by an independent researcher on page 12 in this link.

http://www.finewoodworking.com/pdf/P...ing%20Wood.pdf

Well, we are talking about moisture transfer prevention, not appearance...and realistically it's not all that different to a thick build of gloss varnish or poly, so if a plastic look is what you are after, might as well go all the way!