DIYbanter - View Single Post - Wooden instrument cases designed to absorb moisture & prevent rust

Joe

wrote:

With all my old tools that have factory wooden cases, the cases are
unfinished, nothing on them except some inked or burned-in labels.
The "moisture-absorbtion" thing is bogus, if anything, they'd retain
moisture and rust the tools even faster. Wood will track the relative
humidity changes. Wood was used because it was cheap and easy to work
and it was softer than the tools contained within. Same as plastic
today.

If I had to put a finish on them, I'd use shellac inside and outside.
It's relatively impermeable to moisture and can be readily removed and/
or touched up. Urethanes are hard to recoat and harder to strip. If
you just do one side, you're going to warp the case due to
differential moisture pickup. If you don't believe it, paint a thin
slat on one side with your favorite varnish, wait until it dries and
hold it edge on to a steaming tea kettle. Same reason both sides of a
tabletop should be finished.

Stan

I'd second the recommendation to avoid polyurethane. My favorite is tung
oil. Since I discovered it in the 70s, I've never used anything else.
Even my hardwood floors and kitchen cabinets are treated with it. PU
dings and dents, and you have to sand the whole thing down to fix it.
With tung oil, you just use a little steel wool on the local area and
recoat. The oil soaks into the grain and polymerizes on contact with the
moisture in the air. Of course, I do have to reapply the finish every
few years on the floor and cabinets (surfaces that are subject to wear),
but it's a small price to pay for a finish that really lets the wood's
beauty & character show to its best advantage.

BTW, if you use tung oil, only buy the pure stuff, not the Formby's
crap. I buy it by the gallon at Ace Hardware - their store brand seems
to be tha same as the Park's I used to use. The Behr brand is good, too,
but it imparts a somewhat yellow (honey?) shade to the wood.

For old furniture restoration, though, nothing beats a good shellac
finish. Buy the flakes, and make it up as needed.

Joe