rich brenz wrote:
A friend has a farm with several old barns. He wants to preserve the
barns in their natural "weathered gray" state. The barns are in
otherwise excellent structural condition. Is there an applicable wood
treatment that could be used that would not require power-washing or
prepping the wood beforehand? Remember, he wants to keep the aged
patina of the barns.


The various clear 'weather seal' products would do nothing or very
little to alter the color and patina of the wood. However they
also wold do very little to protect them and they only last six
months or so in sunlight. I've soaked the outsid eof a building
with waterseal and a year later the wood looked like it had
not been treated with anything.

At one time here on the rec a recipe for making your own weather
seal was posted. It was mineral spirits (paint thinner) mineral
oil and parraffin, IIRC. Cheaper than buynig the stuff pre-made
(maybe) and just as good.

I suppose thinned tung oil, might help a little. Tung oil is
expensive, but a volume discount may be had by buying from the
folks who supply it to print shops. If you buy a 55 gallon drum,
the [price/gallonis not that bad.

Linseed oil would be cheaper and not as good for protection and
it would blacken over time.

There used to be an outfit selling an oil finish called penofin, but
they were quite honest about it not lasting in direct sunlight unless
you bought a pigmented oil.

Perhaps your friend should consider that the barns were probably
not weathered gray in the first place. Maybe a bit of restoration
to their original (probable) rust red might be in order.

The most important thing, IMHO, is to keep a good roof on those
barns. Otherwise rot wil take the structure no matter how pretty
the siding looks.

--

FF