This may be old stuff to those of you in wetter climates but something
easily overlooked in dry AZ.
I'm furring out a bathroom wall before installing a vanity I built.
I was trimming some 2 X 6's to length on the chop saw and since they
were ten footers and I don't have a support that long I pressed the
Unisaw into service to support the long end. A handy cutoff of
pressure treated lumber on top of the fence was just the right height.
I finished my cuts, hauled the lumber into the bathroom and called it
a day. Unfortunately, the next day when I hit the shop I discovered
that I had knocked the block of PT onto the saw tabletop and
underneath was a (not so) nice rust spot.
You have experienced the new ACQ treated lumber. It is
extremely corrosive and this is what happens when the
chemicals in it come into contact with unprotected metal. I
did an experiment with it and found that after two months,
there is significant deterioration of common nails, zinc
coated bolts and anything else that is not stainless steel or
double dipped hot galvanized.
Yes, but probably not extensively overnight. Wax alone, however, is
very hard to keep on a working table sufficiently that it doesn't show
wear spots very quickly.
Having a recently waxed surface would undoubtedly have helped in the
short term, however.
I get splots in the summer simply from perspiration drops even in a very
The same thing OP observed can happen w/ less aggressive action w/
almost any framing lumber--it is almost universally wet enough to cause
rusting of bare ferrous metal surfaces.
Yeah, this is yet another case where imo the cure is worse than the
Much other testing has shown the same thing, of course. I'm not
convinced the double-dip galvanized will hold up for really long term,
On Mon, 22 Aug 2005 08:26:49 -0600, Robert Allison wrote
Good advice for any fasteners used on "wet" wood or wood that might become
wet (i.e. sill plates)
Once the fasteners go away, so does the wall.
While renovating this old house, I came across may nails that were corroded
to the point of "not doing squat". The occasional galvanized nail, though
still corroded, looked very serviceable.
Red oak loaded into the shop from the back of a pickup truck in a rainstorm
has exactly the same effect. Didn't matter that the saw table was freshly
waxed. Well, perhaps it wasn't quite as bad as your PT-induced mess, but
it required a 20 minute cleaning.
Good luck with the bathroom project. I'm installing the vanity in our this
morning. It was supposed to happen last week, but when laying things out,
I neglected to properly account for the location of the cold water angle
stop, and had to re-route the plumbing.
I'd rather level ipe with a scrub plane than sweat solder copper pipe. ;-}
On Mon, 22 Aug 2005 12:04:06 -0500, Patriarch
Thanks. This project started a long time ago. Something else always
coming up, like rotator cuff surgery following too much hand sanding
and three months of recuperation, et cetera...
I was REALLY "sweating" it when I had to change some plumbing buried
in a concrete block wall. :-) That's part of the reason that I'm
furring out instead of butting into the existing wall. Figured it was
easier to hide it than to make it pretty. Plus I think the builder
hired a crew of drunk Mexicans to lay up the walls. There isn't a
plumb one in the house. Of course it's a Santa Fe style house so it's
supposed to look like it's made of mud but when you start hanging
cabinets, and so forth it's a PITA.
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