Anton Shepelev wrote:

I was inexact because English is my second language.

Dont' worry about it Anton - even for those of us to whom English is our
first language, we can screw up a thought with the best of them.


I meant a transparent coating that would preserve
the wood texture and color. Untreated wood will be
turning yellower and darker and will become nearly
black in about 25-40 years.

So - I own a log home and have lived in it for 30-ish years. What we used,
back when the house was built, was basic polyurethane. We used satin for
most of the log walls but there are some that we used gloss on. It's my
personal preference that the satin was the better choice. Since UV is not
really much of a problem inside the house, the amount of yellowing that is
associated with poly is not all that great - a bit, but not huge. Darker
has not been any kind of a problem, beyond a modest amount of yellowing.
You are incorrect in your assumption though, that untreated, it will yellow
to becoming almost black. That's just not what will happen. On the
outside - yes that could happen as the logs are exposed to weather, but you
will not experience that inside. That said - you will want some kind of
clear coat finish to simply keep normal cleaning to an acceptable level.

I'm happy to continue this discussion in this forum, or to take it off-line
if you prefer. My email address is in my sig.


It happened with my
previous house, and should like to prevent it this
time.

If you experienced blackening of logs in your previous home, you had other -
major problems that were not related to applying a clear finish. Moisture
would be my first guess. If that's the case - a finish is not going to be a
miracle cure this time around. I suppose it could also be a reflection of
the type of logs that were used, and that's always a consideration, so there
is room for more discussion on that aspect of things as well.



Futhermore, where much vapour is generated untreated
wood will actually decay.

Yes... but how much is "much vapor"? Again - been there done that, and our
experiences differ.

--

-Mike-