All this talk of finishes on wooden planes has sparked a question.

Is there an easy "flowchart" type way of determining what kind of finish is
on a plane (or anything for that matter)?

I think I heard that alcohol will dissolve shellac, but not varnish or poly.
That mineral spirits will dissolve both varnish and shellac, but not poly.

I could be way off here. Any tips or websites that help you identify a
finish?

Matthew Groves

> Perhaps the speaker was talking about 'spirit varnish'? I believe that
> this is a somewhat archaic term for shellac.

Spirit varnish is indeed mostly shellac, but usually has additional resins
added (such as copal, sandarac, etc.)

-----------------------------
Hal Laurent, Baltimore MD, US
laurent@c...

On 16 Jul 00, at 22:36, Matthew Groves wrote:


> 
> I think I heard that alcohol will dissolve shellac, but not varnish or poly.
> That mineral spirits will dissolve both varnish and shellac, but not poly.

This is slightly off the topic of IDing a finish, but in terms of 
dissolving and thinning chemicals, Bob Flexner had an Article 
called "Understanding Solvents and Thinners" in the April issue of 
Woodwork magazine. It includes a nice table titled "what dissolves 
and thins what". Highly informative, and probably worth trying to get 
hold of a copy if you can.

Based on that table, alcohol dissolves shellac (well, we all knew 
that - I buy the stuff by the gallon these days) and thins shellac 
and lacquer. Mineral spirits dissolves wax and thins wax, oil, 
varnish, and poly. 

Someone recently asked for magazine recommendations (other 
than FWW) and Woodwork would be mine, although the latest 
issue is full of p*w*r tool articles for some strange reason. It's 
usually much more galootish.

Ken, hoping this is not a trend.

Ken Greenberg
IT #321; Blue Galoot #82
400 Los Gatos Blvd., Los Gatos, CA 95032
http://www.calast.com/ken/Personal/wood.htm

Matthew Groves said:

> Is there an easy "flowchart" type way of determining what kind of finish is on
> a plane (or anything for that matter)?
> 
> I think I heard that alcohol will dissolve shellac, but not varnish or poly.
> That mineral spirits will dissolve both varnish and shellac, but not poly.

Alcohol will indeed dissolve shellac, but not varnish (poly is just a kind of
varnish).  Lacquer thinner will dissolve lacquer.  Mineral spirits won't 
dissolve any cured finish (which makes it a good thing to use for cleaning).  
There's no way I know of using solvents to differentiate alkyd varnish,
polyurethane varnish, or water-base varnish from each other once they're
cured.



-----------------------------
Hal Laurent, Baltimore MD, US
laurent@c...

Hi All,

It's been said in this thread that alcohol won't dissolve varnish. I
don't really know what I'm talking about here, but I'll throw out the
possibility that's not completely true. Some time ago, a speaker at a
PATINA meeting mentioned dissolving varnish with alcohol. No one stood
up at the time, but another guy and I cornered the speaker later and
questioned that statement. The speaker then said she was talking about
some type of varish which I didn't catch the name of. The other guy
seemed to recognize that name and agreed that alcohol would dissolve it,
so I didn't pursue it further. Am I ringing any bells here?

Best Wishes,
Bob

Perhaps the speaker was talking about 'spirit varnish'? I believe that
this is a somewhat archaic term for shellac.

-Ezra

Bob Nelson said:
> 
> It's been said in this thread that alcohol won't dissolve varnish. I
> don't really know what I'm talking about here, but I'll throw out the
> possibility that's not completely true. Some time ago, a speaker at a
> PATINA meeting mentioned dissolving varnish with alcohol. No one stood
> up at the time, but another guy and I cornered the speaker later and
> questioned that statement. The speaker then said she was talking about
> some type of varish which I didn't catch the name of. The other guy
> seemed to recognize that name and agreed that alcohol would dissolve it,
> so I didn't pursue it further. Am I ringing any bells here?
> 
 

Galoots:
  With all the knowledge on the porch, I'm surprised someone hasn't
already mentioned this - or perhaps I'm just early.  In his book
_Understanding Wood Finishing_, Bob Flexner has a table that gives
solvents and thinners for various thinners.  In my paperback copy, it's
on page 142.
  He distinguishes between solvent - will dissolve a cured finish and
thinner - thins a liquid solution.  He does go on to say that the same
substance can often be both a solvent and a thinner for a finish.

Substance					Solvent for			Thinner for
mineral spirits, naphtha,		Wax					wax, oil, varnish
turpentine

alcohol					shellac, lacquer,			shellac
						water base

lacquer thinner				shellac, lacquer			lacquer catalyzed lacquer
						water base

glycol ether				shellac, lacquer, 			water base
						water base

water						- - -					water base

The accompanying text goes into quite a bit of detail, explaining what
the table only touches on.  He explains how to methodically test an
unknown finish to determine what it is.  It's a good book, worth
whatever it was I paid.
Charlie Rodgers
Clinton, Maryland

Galoots,
	With all the discussion and tables of solvents for finishes, I'm surprised 
no one mentioned Acetone - otherwise known as a universal solvent.  Next to 
Finish Feeder (never
use on a wood plane), I love the smell of Acetone in the morning and use it 
liberally to clean
  many finishes, wax buildup and dirt off tools.  As with other solvents, 
it does not dissolve
many cured finishes.
	If I really want to remove old japanning or red lead paints, I use a water 
based paint
stripper bought from the local hardware.
	As to finishes on wood planes, Randy is correct in saying that most of the 
wood
planes sold without finish.  But, my observation and a PATINA discussion 
and demonstration
  on cleaning tools by Franz Klaus suggest that the owners of these wood 
planes did protect,
  preserve them with a good paste wax.
	Interestingly, Franz was emphatic in saying that only Butchers brand 
bowling wax and
Elephant brand 0000 steel wool be used to apply the wax and burlap first, 
then a cotton tee-
shirt be used to remove the wax and final polish.   Oh well, I'm just as 
emphatic about Finish
Feeder on metal!

***********************************************
*   Karl W. Sanger                               *
*        Desperately seeking antique       *
*                    Machinist Tools!!!           *
* (Email: sangerkw@h...             *
***********************************************