RCM only:

In . com, on Wed, 25
Jul 2007 10:52:49 -0700, John Martin, wrote:
I want to put a preservative on the siding of my house. House is
roughsawn white cedar clapboards, garage is roughsawn pine board &
batten. When built 24 years ago they used bleaching oil on it, which
gave it a somewhat gray color. All of it has since weathered to just
about the color I want, so I'm not interested in stain.

We lived in FL about 18 years ago, and used Thompsons
weatherseal on a couple of things, but it was only good
for about a year in the FL sun and rain, so the following
year I heated a gallon on the Coleman stove outside
and dissolved a couple lbs. of paraffin into it. That
did the trick. I sprayed it on using one of those garden
pressurized sprayers with the air pump handle. The thin
oil (whatever it is) soaks into the wood and carries the
paraffin with it.

We moved 4 or 5 years later, and still no need for
retreatment. I have no idea how long it actually
lasted, but it was a definite improvement over the
Thompson's alone. Oh yeah, clear as water. Treatment
puts the wood about a half shade "fresher"... yeah, ok,
that sort of translates to "darker," but it's more like
unbleaching it rather than actually darkening.

I do want to preserve it, though. There are a few places where
splashback from rain causes some particular problems, indicating it
might need some special treatment. Generally, though, I want to do
all the siding.

For spots like that, I might try 3 lbs. (or more) of
paraffin to the gallon.