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Sandstone Cure
/ Clean
| Areas: |
fireplace hearth, exterior walls,
kitchen sink, paving, floor |
| Problems: |
dirty |
| Q 2344: We have a 1950's
fireplace/hearth made of sandstone
(beige and rose colors). We would like to restore it, as it
looks old and dingy. We can't power wash inside, so what
should we do? What chemicals are recommended? Should we have this
professionally done? Marjie, July 30 |
R1:
Dear Marjie:
1. A solution of warm water and household bleach (3:1).
2. A natural fiber brush (tampico) like the one you use to do laundry.
3. Lots of patience and elbow-grease. Ciao and good luck, Maurizio,
USA |
| Q 2296: I have an
old cap stone from a church roof carved into a fleur de lis shape.
It is approx 100 yrs old, and VERY crumbly/porous. The stone is about
2 feet tall, 1 foot wide, of sandstone, and all the original
exposed surfaces are black with environmental staining.
The stone is probably british, and is a pale yellow colour. Just
by looking at it, its fairly obvious that any sort of grinding will
really damage the surface as well as the ornamental work on the stone.
I'd like to have the stone on display indoors, so can you recommend
any kind of poultice that might strip the worst of the staining -
I don't imagine for a second that I can remove all of it, as the poor
stone has been perched on a roof in an industrial city surrounded
by main roads for so many years! Any help most appreciated as I've
got very attached to my little find now! PS: No, the stone wasn't
pilfered! The church got demolished to make way for a business school!
Rhian, July 25 |
R2: Dear Rhian:
Now that you went through the trouble of letting us know that you
are not thief, I will answer your question!! :-)
Try to poultice it with a solution of water and regular household
bleach (1:1). believe it or not, most of that "pollution dirt" is
nothing but mildew! Once you remove most of the stain with the poultice,
use a solution of hot water and bleach (3:1), and with the help of
a natural bristle brush (tampico) and a lot of "elbow grease",
take out as much as possible of whatever is left. Ciao and good
luck, Maurizio, USA |
| R1: Dear Rhian:
Try some bleach first, and gently rinse after letting the bleaching
action take its course. This should at least get rid of some of the
dark stain (a lot of which is organic in nature). Then with a soft
brush and pH neutral soap, spot scrub the more resistant areas. (again,
gently is the key word). If the stone is sandstone, and has been exposed
to many years of weathering, it is going to be rather fragile, and
even a blast from the garden hose could do considerable damage. Please
try any of these suggestions on a small, inconspicuous area first
before going after the entire piece. Good luck, JVC, USA |
| |
| Q 2266: Someone recently
applied a protective stone sealer to my exterior Colorado buff sandstone
deck, and I am not at all happy with the way it looks now. before,
it was natural looking, like the vertical stone on the exterior walls.
Now, the deck has darkened a lot and has a blotchy appearance that
is not consistent with the vertical stone surfaces. How can I restore
the look of the natural stone, and what would you recommend to seal
and protect it THAT WON'T CHANGE THE COLOR? (I live in Colorado mountains,
and was advised that a sealer is important protect stone/grout joints
from deterioration.) Thanks, GS, July 19 |
R1:
Dear GS:
1. A sealer -- any sealer -- is as good as the operator who applies
it.
2. A sealer for stone will only protect your stone from staining,
certainly not from deterioration. In fact -- although it's still to
be proven that a sealer may actually "help" the deterioration process
of natural stone (!) -- the application of something inside the stone
is certainly not a a natural thing to do. At least in my book. Ciao
and good luck, Maurizio, USA |
| Q 2227: I have a smooth
surface sandstone fireplace that is dirty from age and creosote
around the hearth opening. I would LOVE to restore it to it's natural
state (the home is 80 years old and I'm sure it has never been cleaned).
What would work best - especially since there are very large sections
of the sandstone that make up the fireplace and I don't want it to
get streaks since they would be so noticeable? Do commercial products
work (of which I have not been able to find any specifically for sandstone
- and no one that can tell me of any) - or is there something homemade
I can use? I know it can be cleaned since my sister-in-law had a fire
in her home and her sandstone fireplace that had roses carved in it
- was cleaned beautifully. Unfortunately - NO ONE remembers "who"
cleaned it - let alone what they used!!!!! So I know - after seeing
the before and after of THAT fireplace that it can be done. Right
now it's an eyesore in an otherwise beautiful living room. Any help
you can give me would be GREATLY appreciated. Cathy July 15 |
| R2:
Cathy: Maurizio's is probably the best way to go about this. However,
I do have another suggestion that you might want to try first. Get
a hold of an old fashioned "art gum" eraser --the tan crumbly kind
-- put a drop cloth or paper down on the hearth, and try erasing your
discoloring. Not sure if this will work on your stone, but it sure
does on the white limestone commonly used here in Texas. best to try
it first on a discrete out of sight area if possible. Good luck, JVC,
USA |
R1:
Dear Cathy, I'm wondering how many ways to spell your name there
are in the
English language!! Keep your windows wide open then use a solution
of hot water and household bleach (3 of water and 1 of bleach) with
a natural fiber (tampico) brush and a lot of ... Elbow-grease. You
can find the latter ingredient on isle 12 at your local supermarket!!
:-) Ciao, good luck and don't breath too deeply! Maurizio, USA |
| Q 2226: I just moved
into a home with a rough / brick style sandstone fireplace.
The problem is that around the fireplace at the walls, the stone
has gotten paint on it. It appears as though the owners tired
to wash it off or clean it and now it appears in some areas as a colored
haze in the pores. I don't know if it's oil based or water based paint.
I was thinking of trying a wire brush to remove it. From what I read
on this site, a poultice is best used for smooth surfaces? Would it
even make sense to try poulticing the paint off or the wire brush
or some kind of chemical?, John, July 15 |
| R1:
Dear John: Neither. Poulticing is for deeply inbedded stains only.
Paint is typically on the surface or just barely below it. The
wire brush could be harsh a means. Soak your stone with a paint stripper
based on Methylene Chloride (anything else won't cut it) and a natural
fiber brush (tampico), like the ones used to do laundry. Maurizio,
USA |
| A 2104:
I have moved into a 50 yr. old sandstone exterior home and the sandstone
needs to be clean. I live in north western Pennsylvania were
they used a lot of wood or coal to heat homes in the area. I tried
some different chemical and had no luck. I heard of cleaning it with
a steam or hot water. Please tell me your opinion in cleaning
sandstone exterior homes. J. C., June 23 |
R1:
Dear J.C.: You could try to power wash your stone with a solution
of water and bleach.
There's no guarantee that it'll work, but the chances are quite in
your favor. bleach won't hurt the stone (keep the PSI at no more than
900). Rinse with plain water, once you're done.,Maurizio, USA. |
| |
| A 1963: Exterior
entrance in front of my home is flanked by decorative
sandstone that is beige & some with a blend of a rose tone. 45
years of weather has dirtied the stone somewhat with light black dirt
in the sculpted valleys (gentle curves) particularly; the remainder
of surface is just normal dirtiness. What would be the best
method to use to clean the sandstone? Sanding, wire brushing,
power washing, chemically w/ powerwash? If the last, what chemical
& strength should be used? Sam, May 25. |
| R2:
I once heard
the surprising theory that you can clean sandstone with potato starch!
I don't know how you would do this - maybe make a paste, then wash
it off. Seabrook, USA. |
| R1:
Dear Sam: Power-washing
with a specialty chemical is the best way to go in my opinion. Maurizio,
USA, |
| A 1841: My
husband spilled grease while bbQing on our flagstone patio.
The patio has not been sealed. Help! How can I remove the grease
stains? Pam AZ,May 14.
|
| R2:
Dear Pam: Yes, make a poultice with talc powder (baby powder) and
acetone (available at any hardware store). Ciao and good luck, Maurizio,
USA, Expert Panelist. |
| R1:
The flagstone is quite absorptive, as such the grease may not be completely
removed. You could make a poultice from paper towels and acetone.
Cut the paper towels somewhat larger than the spot. lay them on top
of the spot, now soak in acetone. Cover with plastic wrap and tape
down. 24 hours later remove the poultice, let the spot air dry and
inspect. Redo until the spot is gone. Clean the area with a neutral
pH cleaner. Regards, Steven, USA, Expert Panelist. |
| A 1834: We
just bought a house, and there's a beautiful soapstone double
sink in there that someone painted white. I was able to clean
part of it that wasn't painted, but it's pretty scratched up, and
the rest is covered with a thick paint. It's actually peeling away
it's so thick in the bottom of one of the sinks. 1. What should I
use to take the paint off? I know it's non-absorbent, but I didn't
want to damage it in any way 2. Will sand paper take the scratches
out? 3. After being painted, etc., will I be able to get it back to
it's original beauty? Rosato, May 14. |
R2:
Dear Rosato: Use a paint stripper based on Methylene Chloride. Anything
else won't do.
Follow precautionary direction in the back label of the can. You can
try to sand the scratches up with sand paper, but don't hold your
breath about the results. Soapstone is treated by applying mineral
oil onto it and rubbing in it.Maurizio, USA |
R1:
You should be able to restore the sink. It is important to remove
all the paint first. I would suggest you make sure that it is not
lead based paint first. If it is, I encourage you to just throw the
sink away.
Now, soapstone is a very forgiving stone. Your goal is to sand the
spots down with a rough grit sand paper to get rid of the scratches.
The lower the grit the more aggressive the sand paper. Only use as
low as you have too. Start with a 120 first, if this is not sufficient
then go to 80, etc. Once you have it smooth and even you want to thoroughly
clean the sink to make sure all paint and whatnot is gone. From there,
reverse the process with the sandpaper sanding with each grit successively
higher. You are done when you reach the 300 grit sandpaper. Now mineral
oil and use the sink as you like. Remember, the sink will need attention
frequently. The sink can be cleaned by scrubbing with powder abrasive
cleaners and a brush. Do this when you want to deep clean the sink.
After each deep cleaning re-oil the sink. Steven, USA |
| |
| A 1762: What is the
best way to clean sandstone paving? Martin, April 26. |
| R3:
Hi Martin; firstly we need to know the type of sandstone you are
trying to clean. Do you know which quarry it came from, or which country?
and do you have any technical details on the stone you can share?
These are the basic questions that need addressing before advice on
cleaning can be given safely and effectively. Libi, Australia |
R2:
Hello Martin, Well you know you will not get a good answer without
stating what sized area, what type of sand stone, what surface finish
and is it external or internal.
Well, If it's external and a little mess won't matter, try to:
1. Saturate the paving with clean water first, this will help prevent
loosened dirt from soaking in. ( Very Important )
2. Apply a suitable domestic cleaner (if it's safe for your hands
it's safe for the stone) a little white vinegar may also help. Then
scrub and scrub till your arm aches.
3. Spread clean dry saw dust (absolvent material) over the entire
surface and wait for the soiled water to be absorbed.
4. Sweep up the mess. Go and have a nice cup of tea.
best wishes, Roy, UK. |
R1:
Probably I would recommend using a biogradable detergent and a pressure
washer.
Regards, Steven, USA |
| A 1697: Where a cleaning
company company based in Sydney Australia. We've been asked to
clean a Heritage sandstone building in the City, which is
approx 90 years old. I've tried to get some advice from stone cleaning
professionals in the city and am getting conflicting advice from chemicals
to water washdown (slow spray with brush down after). I'm going to
pass the job over to someone else, as I don't want to put our companies
reputation at risk, however I've done a fair bit of research on this
through the net, and I'm intrigued as to your response to the cleaning
solution. The stone shows signs of algae and copper contamination.
Regards, Richard. April 13. |
| R3:
Make use of German technology as they clean and restore their centuries
old cathedrals on an ongoing basis. I can let you know a company to
contact. Regards Thomas, South Africa. |
| R2:
Dear Richard: You made the smartest move possible by letting the job
go. The wash down technique is the safest, but there are also
chemicals that, when properly selected and used, can do the job faster
and better. but then again, they're not easy to locate, nor to get
precise directions on their use. Ciao and good luck, Maurizio, USA |
| R1:
Dear Richard, have you done the most fundamental of all research into
your heritage sandstone building problem? Have you properly researched
what the soiling is? Unless you know what you are dealing with (and
keep in mind that there could be a number of soiling agents) how can
you think of tackling this job? Have you researched the properties
of the sandstone to see what it is made of, what cements it together,
what structures it might have that might have a bearing on its integrity?
Different sandstones react differently to different treatments. So,
unless you know exactly what is soiling the stone, what the products
of the soiling agents are and what the stone is made from how can
you choose the best method of cleaning??? (Dr. Hans), Australia |
| A 1578 a: Good Morning!
I would appreciate your help immensely. We have a sandstone kitchen,
laundry and bathroom floor. When we moved in our house
we sealed the floors but the sealant did not work. The kitchen
especially needs cleaning as any oil or stain goes right into the
sandstone. We have been told that before resealing we can
clean the sandstone with chlorine or bleach and this will fix the
stains. Is this okay to do and can you recommend a sealant that WILL
WORK and has not to be re applied every 2 years. The people we got
the the sealant from are unable to be contacted now. I am hoping for
a simple answer or perhaps an old time solution that may have been
used in ancient times for sealing Sandstone. We built our own home
and have recorded it.Trijntje, Australia, March 21. |
R3:
Dear Trijntje: It may come as a shock to you, but up until 15 years
ago or so, nobody ever sealed any stone with anything. Nobody ever
used sandstone as flooring material in a kitchen, either!
To remove oily stains, you need to poultice them with acetone, or
other mineral solvent (bleach won't do the first thing about oil).
Finally, as far as the sealer is concerned, you may want to try several
options available on the market. Just leave my own out of the picture,
please! You may want to consider using boiled lynseed oil: two or
three applications (24 hours in between) and see what happen. It will
darken the stone. Maurizio,
USA, |
| R2:
In really ancient times, sandstone was not sealed. It is so absorptive
that I think sealing it is a waste of time and money. As to chlorine
bleach, I think it is too caustic for a soft material like sandstone.
I would suggest a poultice or sanding the floor in the area of the
stain. Try waxing the floor so that the sacrificial coating (wax)
is compromised first. Regards, Steven, USA |
| R1: To remove stains you need
to implement a procedure called poulticing. For now, suffice it to
know that the chemical you have to use is related to the nature of
the stain (i.e.: Hydrogen Peroxide 30/40 volume for organic stains,
Acetone for oily stains, etc.) As far as the "perfect" sealer for
sandstone is concerned, to the best of my knowledge it just does not
exist (and I believe I tested just about any sealer under the sun).
I really wouldn't be thrilled to sell you a bottle of mine, if you
have any expectation of a decent sealing job. Sandstone is just too
absorbent and, very definitely, does not belong in a kitchen. Even
if you could find the "perfect" sealer, its effectiveness would be
short lived. What I mean is that you wish you could get away by applying
it once ever couple of years. Once very couple of months would be
more likely! An old remedy? Try boiled linseed oil on a spare tile
(you may have to apply it three or four times). It's a good sealer
(although, being organic, it will yellow with time). What's more,
it actually stains the stone (it's an oil, right!), consequently any
future staining agent that will go through won't be so noticeable
any more. Maurizio |
| A 1387:
Dear Maurizio, Thank you so much for the advice with the smooth Arizona
sandstone hearth. I
have some follow-up questions and hope I can make myself clear. The
following questions pertain to the stains
on the smooth Arizona sandstone hearth. What is the % concentration
or strength of the hydrogen peroxide I should use on the smooth
hearth? (beauty shops which I have called no longer use it. However,
I may be able to obtain it through my place of employment) How should
it be applied? How long should I leave it on? Should I agitate periodically
with a soft brush? How do I take it up after the allotted time?, wet
vac? or wipe up? The following question pertains to the stains on
the rough-cut Arizona sandstone fireplace where wax has dripped.
I have since removed the wax, but stains (from the coloring in the
wax?) still exist. Since this is a vertical face and nothing sets
on it what do I use to take out stains on this (there is still a slight
stain left after I use vinegar)? Thank you very much for your time.
bob in Seattle. Jan 30. |
| R1:
Dear bob: 30 / 40 volume. Wear rubber gloves.
Put some baby powder in a glass or stainless steel bowl, pour some
HP on it and mix to form a paste more or less of the consistency of
peanut-butter (this is a poultice). Apply the poultice onto the stain
(approx. 1/4" thick) and leave it there until is totally dry. After
that, remove the talc (baby powder), clean with a damp rag or a wet
brush, and check if the stains came out. Repeat it if necessary.,
Maurizio |
| Dear
Maurizio, I finally found some 40% hydrogen peroxide solution (which
has phosphoric acid in it as a stabilizer). There are two parts to
my problem. The first deals with the fireplace hearth (smooth finish).
How do I use the peroxide? With the poultice I purchased (I've used
it about a dozen times with slow results) it is applied and agitated
for a period of 40 minutes and then removed using a wet vac. Do I
dilute the peroxide or use it full strength? How do I prepare the
surface before applying the peroxide? How long do I leave it on? Do
I agitate during application? How do I remove it afterwards? The second
problem pertains to the sandstone vertical face (rough cut and
brick-like). How do I remove the stains from this surface? Thanks
for being patient with bob in Seattle. |
| A 1330: Great Site! Thanks, I hope someone
can help. Recently moved into a house with a rough Arizona sandstone
fireplace and smooth hearth.
Through the years, the hearth has acquired stains. Knowing enough
geology to get me in trouble, I do not want to use anything acidic
on this material. I have used differing ratios of vinegar and water
to remove surface stains and dirt. However, deeper stains will not
come out. Knowing that stone is porous my best guess is that I will
need to grind / sand the stone until the stains are removed and then
refinish by polishing and/or sealing the surface. Can someone please
advise on best method(s), materials and tools to use? Thank you. bob,
Jan 15. |
| R2:
Dear bob: We're a little bit ... confused, aren't we! 1. You say that
you know enough geology not to use any acidic substance to clean the
stone, then you use vinegar (Acetic Acid, that is)! 2. You say that
your best guess to remove deep stains is to grind the stone. I'm wondering
what your not so good guess is going to be! Stains, if they are not
too old, can be only removed by poultice. A poultice is the combination
of an absorbent medium (Kaolin, diatomaceous earth, talc, cotton balls,
paper towels, etc.) with a chemical, which should be specific to deal
with the particular nature of the stain (organic stain, or oily, or
biological, etc.). Considering that's a fireplace, the typical stains
occurring on the hearth are usually organic. You can try to poultice
them out using Hydrogen Peroxide 30 / 40 volume (available at a beauty
salon near you). If you will turn out to be successful, then you will
proceed to seal the stone with a good quality stone impregnator (several
applications will be needed). No offence meant, I was just teasing
you a little bit! Ciao and good luck, Maurizio |
| R1: bob..
you might want to try a poultice type stain remover. Directions and
instructions can be found elsewhere on this site. Grinding and or
sanding probably won't do much good on this stone as the stain has
most likely penetrated deep into the stone. Also, sandstones do not
polish very well , but it is important to seal the stone, and periodically
reseal it. JVC |
| Thank you
to Maurizio and JVC for their replies. Sorry for the mix-up with the
vinegar (acetic acid). I was thinking one thing and typing another.
(So much for multi-tasking :-) I have called around the area where
I live and that led me to a company in Seattle, Washingtion which
recommended the use of a poultice. I've since purchased and used it
(3 applications) with little or no results --- can't see a difference,
but I will continue to use it. I was told mult-applications would
be necessary. The facing of the fireplace is also Arizona sandstone
which is done in rough-cut, brick-like shapes. Through the years candles
have dripped wax down the front of the stone and have left stains
and wax build-up. Last night I had an idea on how to remove these.
First, I used a heat gun to melt the wax. As the wax melted I dabbed
it with a soft cloth. I did this until there was little or no wax
left. However, this left a stain. (The only reason I can think of
for this is the coloring in the wax was left behind.) After this step
I tried with vinegar using both a wire brush and a soft brush. I kept
applying vinegar, using both brushes, until the sandstone looked fairly
clean. I then rinsed with water using the soft brush. This method
was very successful. Questions: What type of liquids should I not
use on sandstone? Would peroxide work better? back to the subject
of the smooth hearth. I will try peroxide on this per recommendation.
However, I have more questions. 1. What chemical and mechanical treatments
should I not use and why? 2. How can I remove surface scratches? 3.
Is it possible to fill chips in the surface? What can be used for
these? Thank you very much for your help. It is really appreciated.
bob in Seattle, Jan 18 |
| Dear bob:
I don't quite understand. You want to know what to use to make the
surface of the stone smooth and mention that you're going to use Hydrogen
Peroxide. That is something you should be using to poultice the stain
out, not to smooth the surface (by the way, in most instances, "professional
poulticing kits" turn out, in my opinion, to be just marketing gimmiks
that only help their manufacturers to put their kids through college!!).
To remove the scratches you have to sand them with a rather coarse
sandpaper (better if you use that sand-cloth used for metals) and
then, to smooth the surface, you should sand it with finer and finer
grits, until you reach the desired result. To fill the chips, if they
are deep enough, you can try with matching grout. Ciao and good luck,
Maurizio |
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The views expressed in this section are not of FindStone. |
| I've
just spent about ten minutes looking at your site, but from what I
did see I am very impressed. It looks very helpful and user friendly
I will use your site for various things in the future, Thank you for
this resource. Randy, CLEANING CO. , FL, USA. |
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