drying linseed oil/turpentine finish

[Don Dougan <dondougan@zzzzzzzz>]

Norman,

I have never used the turp-oil mixture on slate or any other stone (I
have used it on iron and steel tools, and on wood), so I am not sure what
I have to say will apply.

I didn't reply right away because I thought somebody else on the list
might have used the mix as a finish on slate and I wanted to see what
they said.

Here are a couple of thoughts I have:

Next time, you can go to the art supply store and buy some Japan Drier
and add a few drops to your mix, it will accelerate the polymerization of
the linseed oil, but I don't think it will give you any higher a gloss.

When I use linseed oil as a finish on wood (which is porous like slate),
I can't help but remember the old saw that I was told by my High School
Shop Instructor a long time ago about applying an oil finish:  "Once a
day for week, once a week for a month, once a month for a year, and once
a year for the rest of your life."  The point being that as long as the
oil penetrates the material, you aren't done applying it.

When I apply it to wood as a finish, I apply it liberally to coat the
surface.  After about 15 to 30 minutes (before it starts to get tacky) I
wipe the surface down with a clean lint-free rag (like an old T-shirt)
and allow it to dry thus.  At that point I repeat the process, for as
many times as I think it takes to achieve the finish I am looking for.  I
never have followed that old saying very far -- no more than five or six
coats initially, and perhaps another a few years down the road -- but
then I am not usually trying to achieve a high gloss, rather a satin or
eggshell finish.  I assume this is the gilded piece you were working on
recently(?), so IMO the low-gloss would serve as a nice contrast to the
bright gold.

I'd be interested in what anybody else has to say who may have actually
used the method on slate.

Good finishing to you,
Don

http://www.dondougan.com