James Freeman on mon 1 mar 10
BOREDOM ALERT! Very, very long. If you are not interested in wood
finishing, CLICK AWAY NOW!
Part 1:
Eleanora...
In another post you asked about rottenstone. It is still readily available
as far as I know. Rockler Woodworking Supply still sells it for about $8
for a 1 pound box. You can also get it through lapidary supply shops and
through metal finishing supply shops, where it is called either tripoli or
brown tripoli. In this bulk form it is $2-3 per pound. Here is one
source: http://www.gravescompany.com/grit.htm . Rottenstone is typically
used to pound down the fully cured varnish surface after it has been steel
wooled or pumiced, or both. The typical procedure is to sprinkle mineral
oil on the surface, followed by some rottenstone, then buff to the desired
sheen, followed by a coat of paste wax. An alternative to pumice and
rottenstone is to use automotive rubbing compound followed by automotive
polishing compound. These are sold in plastic tubs, and are found in the
carwash section of any hardware or auto parts store, or in the auto
department of places like Walmart or Sears. I prefer Turtle Wax brand, but
they are all about the same. Again, follow up with a coat of paste wax. A=
s
a note, for my own work I very rarely go this route.
Wood finishing is a complex topic, and is hard to lay out in a simple
email. There are many books on the topic, and I recommend anything written
by Bob Flexner.
There are many ways to get silky wood finishes, with varying degrees of
durability. The primary step, however, is in the sanding stage before any
finish is applied. I employ a process I call double sanding. After sandin=
g
wood, it feels very smooth. This is fleeting, however. When you sand
through progressively finer grits, the object is to remove the rough and
fuzzy bits of wood, then to remove the scratches left by the previous step,
then to remove those scratches, on through the grits until the scratches ar=
e
so fine that you no longer see them. The problem is that sanding only
removes some of the fuzzy wood fibers, while others are merely compressed
down. Though the wood feels smooth at this point, those compresses wood
fibers will eventually pop back up and spoil your finish. The first secret
is to sand through all of your grits. When you are done, lightly wet the
wood with a damp sponge. This will raise all of the compressed wood fibers
which you couldn't feel earlier, and would have negatively impacted your
finish. You will be shocked at just how rough your supposedly smooth board
really was. Once the wood dries, another sanding with just your last few
finest grits will remove these fibers, leaving you with a very smooth
surface. I personally rarely go beyond 320 grit, but some folks go to 400,
600, or even 1000 grit. Another sanding secret is to either vacuum the
surface or wipe the surface with a tack rag between grits. This removes
loose bits of grit which would be picked up by the next finer sandpaper and
cause scratches.
Finishing is your next problem. For things like cutting boards I personall=
y
do not like to use any form of film finish, as bits of finish will
inevitably end up in your food. Typically these finishes can't hurt you
once they are fully cured, but I prefer not to eat them, and they really
look bad when they get chewed up by knives and such. I like to use ordinar=
y
mineral oil, which I apply liberally with a rag, then buff with a green
Scotchbrite scrubbie for rougher things or a grey Scotchbrite scrubbie for
smoother surfaces. Wipe away any excess with a clean cloth. If you want a
completely food-based oil, walnut oil is a good choice. It is available
through both woodworking stores and health food stores. It's not cheap, bu=
t
you don't use all that much either. Do not use salad oil, as it partially
dries and leaves a sticky, gummy mess. Avoid linseed oil, as the raw
variety will also get gummy, while the so-called boiled variety contains
metallic dryers which, while supposedly safe when dry, I prefer not to eat.
BTW, mineral oil is available in any pharmacy department. It is baby oil,
but without the foul stench.
End of part 1
James Freeman
"All I say is by way of discourse, and nothing by way of advice. I should
not speak so boldly if it were my due to be believed."
-Michel de Montaigne
http://www.jamesfreemanstudio.com
http://www.flickr.com/photos/jamesfreemanstudio/
http://www.jamesfreemanstudio.com/clayart/
On Mon, Mar 1, 2010 at 10:44 AM, Eleanora Eden wrote:
> A friend of mine is hoping to sell bread boards and other wood
> wares. I have seen very silky wood finishes. I have been asking
> around and getting tips here and there.
>
> Any wood workers on this list willing to share their expertise on
> this front? My dad did great wood finishes and I know he swore by
> rotten stone. I have used it but have not gotten the fine finishes he
> got or that I am seeing in the galleries.
>
> Thanks,
>
> Eleanora
>
> --
> Bellows Falls Vermont
> www.eleanoraeden.com
>
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