Will Indiana Limestone take a polish?

["Charles Kibby" <ckibby@zzzzzzzzzzz>]

 If you put a sealer on Indy Limestone for exterior sculpture be ready for
The 'skin' to come off about 1/2 below the surface. I last saw this with
some of Doug Hydes figures. It was HORRID!

The thing with sealers is that there are so many different "stone Sealers"
on the market today.  Some of these are topical coatings which cover the
surface, and effectively smother the stone.  Not a good thing for any
stone, and they can cause all sorts of problems like spawling of the
surface
I agree with almost all of the things posted by JVC, but there are some
clarifications here that might help things become easier to digest.  There
are two basic types of treatments for stone available on the market today -
surface coatings (membranes) and penetrating sub-surface impregnators.
Unfortunately, the term 'sealer' is used interchangeably between the two
basic types of treatments so it is imperative that a more complete
description of the treatment is given when talking about options.

Any surface membrane-forming coating on stone is a printed invitation to
eventual failure, and you can accelerate that schedule for outdoor
applications by a factor of 10 or more.  Anytime the surface of a stone is
coated with a hydrophobic moisture-resistant surface, it will increase the
chance of catastrophic failure if moisture gets below the coating (HORRID!).
There's not a clear coating on the planet that can give an expectation of
more than ten years of viable life span before UV exposure causes it to
begin to fail.  Any coatings manufacturer rep will backpedal faster than
Bush into Baghdad if you push them on this issue.....so if you like to
slather your sculpture with Akemi polish, or any other membrane-forming
non-breathable treatment, prepare for regular re-applications on a
maintenance basis if you want to maintain that full bore color-enhanced
look.

The only logical way to get a full experience of a stone's color is to
finely hone and/or polish the surface to close up the pores and get that
fine-grained glass-like appearance that transmits all the visual data to
your retina.  Remember keeping river rocks in Mason jar full of water to get
the full impact of the colors?  That's what happens when you polish a
stone - you're allowing light rays to penetrate deeply into the matrix, much
more so than if the surface were honed (washed out, bleached appearance).
When you polish stone, you are making the micro surface like glass.  The
problem is that most of us like to work with calcareous material (limestone,
marble, and everything in between) and the acid rain prevalent in most urban
environments will nuke that glass-like surface very quickly.

The other generic type of treatment is the penetrating type (sub-surface,
impregnator, etc.). This is a treatment that has only been on the market for
approximately thirty years or so, and they get more and more sophisticated
as time goes on.  Basically, you apply the liquid, the carrier
(petroleum-based or water-based) transmits the active solids into the pores
of the stone below the surface (for solvent-based carriers as much as 1/4
inch or more, depending on the substrate), the carrier evaporates and the
actual solids left in the matrix between calcium or silicate particles does
the work of resisting the penetration of moisture while allowing moisture in
a vapor form to escape from the stone if it should penetrate from elsewhere.
The beauty of these types of treatments is that they act like liquid
Gore-Tex, repelling moisture in liquid form but allowing the migration of
moisture vapor (some as high as 98%).  Check out this well known
manufacturer for an example of a 'sealer' that has become an industry
standard: http://www.prosoco.com/Product.asp?ID=82

There are indeed many types of 'sealers' and it's not a simple subject, nor
are there any simple solutions.  As I tell my clients, if you must have a
polished surface, be prepared to invest maintenance resources in direct
proportion to the level of shine to keep it that way.  Sorry if I've muddied
the waters further, but I hate to see a sculpture with heaps of effort
ruined because of ill-informed decisions.

Good Luck,

Chaz

CK Arts, Inc.
P: 310-877-3112
F: 310-476-9216
E: ckibby@-----------
Website: ckarts.com