Care and Cleaning of Gravestones (6)
Many people do not realize that the early or "colonial" era gravestones of the United States are in fact much larger that what you see above ground. Because of the thickness of these early gravestones half of the length will be found below ground level. This was not only done to ensure that the gravestone would remain straight and sturdy, but for other reasons such as the frost over many northern winters would push the gravestone up. A gravestone with a shorter base would over time be prone to falling over. The use of the long base would prevent this. With the turn of the 20th Century, gravestones gradually became thicker & heavier eliminating the need to set so much of the stone below ground. A concrete foundation was simply poured to keep the stone in place.
There are numerous reasons why one of these early gravestones might start to lean. Sometimes the tilting of the gravestone was caused by the grave collapsing over the years, and the settling caused the stone to tilt in that direction. Adverse weather conditions such as the winter frost as mentioned above or abnormally heavy rain seasons could lead to this.
You will also discover that stones of this nature are still in use today. Government issued veteran gravestones are 42 inches long, with half in the ground.
Resetting one of these stones is not an easy process to undertake and the following things should be kept in mind when working with this type of gravestone:
- Before attempting anything of this nature be sure that if at all possible you have written permission.
- Research local laws or cemetery rules and regulations to be sure that this type of work is legal in the cemetery. You may discover that some local governments will not the use of specific tools such as A hoe shovel, or pick except by cemetery workers.
- Attempting to straighten the gravestone by pushing or rocking can and will cause it to break off at ground level. This should not be done.
- You should first have some idea of what caused the problem in the first place, the type of stone, and be able to gauge with accuracy the degree of wear the gravestone has undergone. In the case of the type of stone if you're dealing with a gravestone from another era, it's probably not made of the durable granite almost universally used today. Red sandstone, commonly used during the American Colonial Period, and marble, which became popular during the 19th Century after quarries were opened in Vermont, are among the historic materials which are very vulnerable to erosion.
- To properly align the gravestone you will carefully need to excavate the base of the stone. Keep in mind that the stone will be quite heavy and unless you have the proper tools and equipment to heel the stone in place during the excavation process you may end up with a larger problem that you started out with. For more information on this area, please see Lifting Stones With A Tripod Hoist.
- Once you have the gravestone reset in it's proper position, you must be sure to repack the soil surrounding it hard enough to support the gravestone. Take into account that a good rain may come along and loosen the dirt causing the stone to start tilting all over again.
You may discover that it may be for the best to simply leave the tilting stone as you found it and not take the chance of doing further damage. If you are not experienced in this type of work it is highly recommended that you do not attempt to re set the stone. The state, county or local historic society or museum should be able to advise you and provide you with the names of restorers in your vicinity. Some museums are even directly involved in gravestone restoration, with experts on the premises. If the damaged gravestone is from the modern era, any local monument business should be able to repair it. In the case of a crooked/sunken stone, the cemetery may be responsible for providing a new foundation, especially if the burial involved a "perpetual care" fee. Again, the costs will vary; don't hesitate to ask and shop around.
"There is so much misinformation available on the right way to document a gravestone marker that it is a wonder that any of them are still standing."
- Maureen Taylor
The World Wide Web has been a godsend to those both trying to provide as well as those searching for information in the area of cemetery preservation. The number of web sites pertaining in some fashion to this area has grown vastly in the past several years. For example, if you were to go to the Google website and enter the words "cemetery preservation" as a search field, you would get back a list of some 355,900 possible matching links. On the words "cemetery restoration", some 49,00 possible links. And more are being added every day. As a direct result of this rapid growth, a problem not limited to this specific area, but widespread over the entire Internet has shown it's face. Anyone, anywhere in the world with access to a computer and a little basic knowledge of the aspects of getting a web page online can put just about any information that they feel like out there. In many cases this could (and should be) be viewed as a positive thing. However, in reality many of these people are placing information out there for others to find that is incorrect and as a direct result encouraging people who are trying to do the right thing to go out to the cemetery and do things that should not be done.
One topic that has been debated for quite some time now is the use of Shaving Cream on a gravestone in order to make the carvings more visible. Most people who have some experience in this area know that this is not a good practice and by doing so you can cause irreparable damage to the stone itself in many cases. And while there are a number of web sites that encourage the reader to not use this method of reading a stone, a good number of them do not go into any detailed explanations as to why it is not a good practice and what effects it can have on the stone. They do not tell you that most brands and types contain, among other things, perfumes and stearic acid. They also do not inform you that the pH of typical shaving cream is in 5 range, which makes it more acidic than acid rain. Many of the newer shaving creams such as the Gillette Series line have replaced stearic acid with palmitic acid which while somewhat safer for use on your skin should still not be used on the surface of a gravestone.
They say something to the effect of "Do not apply shaving cream or other chemicals to the stones, as this can also cause damage", and assume that you will take them at their word and not do it because they told you so. . Even the Association For Gravestone Studies is not constant in dealing with the subject on their web site. If you look for the information on the Preservation page, you find the following somewhat detailed information;
"Why can't I use shaving cream to highlight inscriptions on difficult to read stones?
Our professional conservators tell us it is definitely not a good idea to use shaving cream on porous gravestones because there are chemicals, greasy emollients, in shaving cream that are sticky and very difficult to remove from the stone with a simple washing. Indeed, even with vigorous scrubbing and lots of rinsing, the cream fills in the pours of a porous stone and cannot all be removed. The result of leaving it there is that in time it may discolor or damage the stone."
However if you were to look on the F.A.Q. page, it states only:
"Don't use shaving cream, chalk, graphite, dirt, or other concoctions in an attempt to read worn inscriptions".
Found on the Ancestry.com website is the following, reprinted from the November/December 1994 issue (Vol.12 No.6) :
"Put the plastic bag on your hand; squirt shaving cream either into your hand or directly on the stone; rub cream all over the stone, squeegee the stone in one direction over the inscription. If the stone is large, you may want to do parts at a time since the cream will dry quickly on a hot day. If the inscription is not clear, apply the cream again, and squeegee in another direction. Some information may still be illegible, but you may get part of a name or date that you couldn't read with the "naked eye." If the stone is shiny granite, shaving cream in the inscription will allow the stone to photograph much better. Since the cream does not harm the stone, and water or rain washes any excess cream away, this method is safe."
Now to make things even more confusing, if you were to further research the Ancestry.com website you would find this in Ancestry Daily News edition of 6/1/1999:
"Do not apply shaving cream or other chemicals to the stones, as this can also cause damage"
In all fairness, some web sites start to tell you why to not use this method, along the lines of what AGS has done on the preservation page, such as the Texas State Historical Commission, who state on their page "People should avoid using harsh substances with emollients, such as shaving cream, to reveal inscriptions; the oils from these products are not washed off by rain and can cause the stone to deteriorate.". In the Newsletter of the Canterbury Genealogy Society Discussion Group, February 2000 issue, they state "Shaving cream does, indeed, leave an acid residue that does not wash off. It destroys marble and limestone".
However, if you are going to tell people not to use this method, then an explanation of exactly why this should not be done is in order. Otherwise why should someone take those words at face value over those that tell a different story?
So, why not use Shaving Cream in order to make the stone more readable? Careful research of the question yields some insightful and valuable information on the subject. To begin with, the exact formulas for shaving creams are corporate trade secrets however, it is common knowledge that most contain emollients to soften the skin, while at the same time protecting it. Shaving Cream also contains a chemical known as stearic acid (defined by Britannica.com as "a colourless, waxy solid that is almost insoluble in water") which will cause the surface of the stone to exfoliate, especially if that stone is either granite, marble or limestone. Granite is an igneous rock, and therefore highly susceptible to any type of chemical weathering. By putting shaving cream on the stone, you are doing the same thing acid rain does over a long period of time, only you are hastening the destruction. Marble and Limestone are highly reactive to acids, and will actually sublimate in the presence of hydrochloric acid. That means it will go from a solid to a vapor without a liquid stage, as it releases certain parts of its chemical structure. Further reason for not using shaving cream lies in the potential damage over a very long period of time, not just a few years. The chemicals in shaving cream will permeate into the microscopic pores of the stone and will not be readily washed out. These chemicals, which consist of soaps, mineral oil, fatty alcohols and other skin conditioners are all organic compounds which are biodegradable. Since they are biodegradable, they provide food for microscopic organisms, fungi, mosses, etc. The growth of such organisms in the pores of a stone causes expansive forces which will gradually cause microscopic particles of the stone to be flaked off. These enlarged microscopic pores can also collect moisture in wet freezing weather and the freezing action causes microscopic fractures of the stone because, as you know, water expands upon freezing. In other words, only completely chemically inert materials should ever contact a tombstone.
The rule that should be followed is to do no harm, and nothing irreversible. Anything that dislodges bits of stone IS damaging. Likewise, don't use any chemical compounds that are untested or cannot be removed completely. The residue from Styrofoam is inert, therefore not chemically damaging. Shaving creams and other household cleaning chemicals have active (and usually acidic) components. If you ever have an opportunity to observe professional stone conservators work on old stones you will find that they begin cleaning with the weakest possible substance (water) progressing to other cleaners as appropriate. When chemical cleaners are called for they use very weak (non-acidic) cleaners and the absolutely flood the stones with water to wash away as much residue as possible.
So now we have solid, logical reasoning backed up with hard facts as to why not use shaving cream on a stone. But again falling back to the problem at hand, for every web site that will tell you to not us this method, there are just as many sources on the Internet today that will tell you exactly the opposite. For example, if you were to go to the Ghostseakers Genealogy Tip of the Week Web site You find this as a recommended method:
"Shaving Cream Method - Place some shaving cream on the stone. Run a squeegee across the stone so that the shaving cream remains imbedded in the lettering. Photograph. Using your water bottle and spray bottle, clean the stone thoroughly and wipe gently with a soft clean rag."
And Dick Eastman on his Tombstone Rubbing hints web page has this to say:
"There appears to be two successful ways to read old tombstone inscriptions. These are so successful that there are reports of reading inscriptions that have defied older methods. The first method is very simple: use shaving cream! First, wet the stone. Then cover a section of the stone with the moist cream and then scrape the excess cream of with a piece of Styrofoam. The cream goes into the inscription making it readable. The cream must be moist to work. Neither the Styrofoam nor the cream will damage the stone. This works very well when making photographs of a tombstone. Try to photograph in the early morning or late afternoon when the sun's rays are at an angle."
It's interesting that Mr. Eastman not only tells us that this will not harm the stone, but to not bother washing it off, but does not mention at all any cleaning procedures. Are we to assume that we should just leave the cream on the stone? And to further compound the problem, the exact same information, word for word is found not only at www.purleyradio.co.uk/files/cemrub.txt but again the exact same information is found reprinted at: bally.fortunecity.com/mulligan/173/pages/newsletters/i_s_1995-07.txt
The Heritage Tours of Dover, New Hampshire had the following advice to offer:
"** To read or photograph a stone, squirt a mist of water from a spray bottle onto the stone. Then apply a generous amount of shaving cream from a can. Using a squeegee," shave" the stone. The shaving cream will remain in work carved letters and details for a short time, making it easier to read or photograph. Wipe off cream when finished."
Well, at least they told us to wipe it off when finished. Which is somewhat more responsible than The Dallas Jewish Historical Society, who tells us that not only is it safe to use shaving cream, but to not bother cleaning it off the stone as it will wash off during the next rain:
"For dark-colored stones, spray the face of the stone with non-mentholated shaving cream. Squeegee this across the face of the stone with either a squeegee or a piece of cardboard. The white shaving cream will stay in the low areas of the stone and provide the much-needed contrast for your picture. It is also soluble in water. As long as the stone is not marble, the shaving cream will not hurt the stone. It will wash off in the next rain."
John B. Grimes, who on his website CEMETERY KIT informs us that in his opinion :
" The very best way to record the inscriptions is to photograph them and THE best way is to fill the inscription letters with a bright white, temporary, non-damaging material that will bring out the inscription so that it nearly shouts at you - this is done using ordinary canned shaving cream to fill the letters, and a squeegee to remove excess shaving cream from the flat surface - leaving the letters VERY clear and highly readable."
He then goes on to recommends bringing with you to the cemetery the following items:
A large, inexpensive, can of shaving cream. Barbasol works good and is cheap.
A rubber spatula such as is used for spreading body putty at a car body shop. Can be purchased very cheaply at most auto part stores. A 4" or 5" metal putty knife also works, but for the purist, a metal object scraping across a headstone is anathema. This spatula or putty knife is used to spread shaving cream over the face of the grave stone, forcing the bright, white, shaving cream into the engraving on the stone. (Note: The purist will claim that you should not use shaving cream. While I have heard this, there has never been a shred of evidence to convince me that the occasional application of shaving cream is going to do ANY harm.) Certainly a well conducted photo survey of a graveyard, particularly a small family plot that is no longer being cared for, and the forwarding of the results of your efforts to your state Archives, will do more to preserving the information than any other thing you can do, as it obviates the need for others to come to the graveyard and go through the ordeal of clearing it (and possibly damaging some stones in the process) and "defiling" a headstone with shaving cream every decade.
Rubber window washing rubber squeegee, about 9" or 10" in width (an old windshield wiper works in a pinch). This tool will wipe away the shaving cream on the surface of the stone leaving an amazingly clear and readable stone face, suitable for photographing. You will be amazed at how formerly unreadable headstones become crystal clear. You can use your hand for all of this shaving cream spreading, but by the time you have done two or three stones, you will be covered in shaving cream, as will your camera, tools, friends, bushes, etc. It is diabolical stuff.
Paper Towels - to keep the shaving cream at bay and wipe your sweated brow."
Dan Maxson recently authored a web page entitled "Cleaning and Reading Tombstones" located at http://www.enchantedmountains.com/Tombstones/Tombstones.htm . In the page he manages to give just about every single piece of bad advice that he can think of on the subject, including the following:
"I cannot find any possible way that shaving creme can damage a stone. You men have used it and know that it does not contain abrasives that will damage your skin; so, it will not wear the stone away. The big objection that I have heard is that shaving creme is acid and will eat the stone away. If you read the label, you will note that it does contain stearic acid."
"The main reason that I rinse the stone is for esthetic reasons. People will feel better about it. If you leave the shaving crème, the next rain will wash it off and it will help neutralize the acid rain or soil to a small degree. I use a pump up garden sprayer for rinsing the stones."
And just so you do not think that this problem of disinformation exists only on the web, we have the words of wisdom that John Kent had to offer on VAROOTS mailing list:
"The sky is falling! The sky is falling said Chicken Little. Now y'all stay out of these big ole sky scraper buildings made of all this stone that the janitorial crews put all this nasty cleaning stuff on cause the building might collapse on top of you. I'm surprised the Stone Rights Advocates don't jump up and down and have a little hissie fit every time they see a cleaning crew desecrating the stone on these sky scrapers with all their strong cleaning reagents. Think of it like this: if you can't read the markings on a tomb stone it isn't doing you much good. Gutson Borglum would roll over in his grave if he knew he could have used shaving cream instead of a chisel to create all his masterpieces. Just rub a little bit here and a little bit there and the stone would dissolve and disappear right before his eyes and leave his design."
And finally, John is not alone. In what in my opinion has to be one of the best examples of arrogance that I have seen to date, Judy Harris on the CEMETERY mailing list voiced her feelings on the subject of shaving cream in the following words:
"I have cleaned several family tombstones dating back to 1800 with shaving cream and yes, folks, I even have tombstone rubbings from this small family cemetery in Southern Indiana. Sue me if you want, but they are MY, I repeat **MY** family and some of these stones were unreadable any other way. One was not readable (period). This is *my* family. *I* carry their blood in my veins as do my children. I take those children 400 miles round trip every year to pay respects to great great grandparents who were dead before my grandparents were even born. The last burial there was well over 100 years ago and I am the only person who has visited for many many years."
To clear up a common misconception, lichens do not eat the rock, rather they naturally grow on stone surfaces that are available to them, whether these surfaces are naturally occurring or are artifacts of human activity. You will not be helping to preserve the stones by removing the lichen. The gray and orange patches formed by lichens on gravestones give a distinctive character to an old cemetery. These attractive "time-stains" not only enhance the appearance of the churchyard but are often of some rarity for which, like many other organisms, the cemetery is a wildlife sanctuary. Many lichens require a particular type of stone on which to live and, in many lowland districts, the cemetery may be the only undisturbed location in the area for many of these types of stones.
There are differing views as to whether lichens damage the stone on which they are growing or whether they protect it. There is evidence that the acid substances produced by lichens can attack the stone, but this effect is limited to a very thin layer immediately under the lichen. Any small cracks present or caused by this process will probably be infiltrated by the fine root-like hairs (fungal hyphae) of the lichen and this may cause more damage. It has, however, been argued that any damage caused by these processes is less than would be brought about by the weather if the lichen was not present. The tough, rather thick, lichen can protect the underlying stone from the weathering effects of wind, rain and frost. On some soft stones in exposed sites the lichens may eventually cover raised areas where the surrounding stone has been eroded away by natural weathering.
In some circumstances it may be necessary to remove lichens and various methods have been used with success. You'll never get a crustose lichen off a rock and keep the rock's surface intact. Lichens cause differential weathering on the rock which is visible as stains. On basic rocks the lichens will stain the rocks by their acids. The lichens also shield the rock from radiation which can lead to differences in color even on acidic rocks. If the purpose is to enable an inscription to be read, other ways of doing this should be tried first before the removal of the lichens. These methods, to increase the clarity of an inscription, include wetting or looking at it in the twilight with a torch shone along the inscription on a gravestone at a low angle. This will enable many worn inscriptions to be read. If it is deemed that cleaning is essential, only the minimum area necessary should be treated. This may be done by physically rubbing the lichens from the surface. Where this is done on a smooth stone the result may be unsightly as it is almost impossible to remove many crusty lichens from the lettering of the inscription. The lichens remaining in the lettering and cracks will probably regrow but rare lichens may have been lost from the surface. Another physical method that has been used is to cover the area to be cleaned with black polythene. It may take some months for the lichens to die but they may then be removed with a brush.
There is a new product, BIO-LICHEN OFF, produced by Sunnz International Ltd,
P.O. Box 13-598, Onehunga, Auckland, New Zealand that is said to be a fast acting and effective concentrated product designed to remove all Lichens, Moss and Fungal growth from most surfaces. More information can be found at:
The Association for Gravestone Studies suggests that Calcium Hypochlorite (e.g., Chlorine, "HTH," "Shock Treatment") is effective for the removal of biological growth. It is a granular product that is not to be confused with "liquid chlorine" or sodium hypochlorite. Calcium hypochlorite is available from swimming pool suppliers. A suggested cleaning solution is one ounce calcium hypochlorite to one gallon hot water. Please keep in mind that this product should be used only when a waterhose with a good water pressure (e.g., 55 psi) is available. Any water pressure over 40 psi has the potential to cause significant damage to a stone, depending on the condition of the stone. Saving Graves recommends alternatives to this method if at all possible.
Whatever method is used care should be taken to treat as small an area as possible and not allow the chemicals to drip onto adjacent parts of the stone or statue. Before commencing try to get an experienced lichenologist to check that there are no rare lichens present. Remember, before you kill them, that these lichens may have been growing on the stone for many years.
THE CLEANING OF MARKERS OF HISTORICAL SIGNIFICANCE REQUIRE SPECIAL CONSIDERATION. IF THE MARKER YOU ARE ATTEMPTING TO CLEAN IS OLD OR APPEARS TO BE BRITTLE WE RECOMMEND YOU CONSULT AN EXPERT BEFORE ATTEMPTING TO CLEAN THE MARKER.
Pressure Washing of gravestones is a somewhat new and serious threat to cemeteries. A search of the internet will find hundreds of websites, all with a similar wrong message - "In most cases moss or most stains can be removed by pressure washing and professional cleaning". Most of these websites are for monument companies and seem to be making use of the same standard FAQ. One website goes so far as to imply that The Association for Gravestone Studies is aware and approves of the use of pressure washing for gravestones. However a quick glance of their website proves this not to be the case. Others still are for Cemetery Monument Restoration services - people that should know better than to use this method.
The National Center for Preservation Technology and Training (NCPTT) recently organized a seminar and workshop on the conservation of gravestones and other monuments commonly found in cemeteries. More than 60 participants from around the nation participated in the events held in Natchitoches, Louisiana. The participants represented a wide array of individuals involved in cemetery preservation, including cemetery association members, State Historic Preservation officers, national and state park employees, K-12 teachers who use cemeteries in their lessons, doctoral students con-ducting research in cemeteries, cemetery caretakers, monument builders, and family cemetery owners.
Following the conference, NCPTT held a two-day workshop including hands on condition assessment, safe handling procedures, and conservation treatments. The conservation treatments encompassed cleaning tests using water, hand scrubbing with soft-bristle brushes, chemical methods, and low-pressure washing (less than 600 psi).
The fact that they would recommend any type of pressure washing is of great concern. While this method may produce the desired results of a clean gravestone, Saving Graves is strongly opposed to the use of pressure washing. There is simply far too much risk to the stone using this method. Any water pressure over 40 psi has the potential to cause significant damage to a stone, depending on the condition of the stone. A standard home garden hose with a nozzle attached will put out on average about 50 psi and the nozzle may actually cause the stream to be more direct than the stone can handle. The use of a pressure washing system on a gravestone will not only remove the outer surface of the stone, but expose the softer interior pores. These newly exposed pores will have a tendency to catch and hold onto grime and moisture that travel through the atmosphere. Trapped moisture within the stone from pressure washing will lead to a shorter stone life. If used on older stones, pressure washing can and will flake off entire layers of old brittle stone.
Non-ionic detergents such as D/2 Biological Solution, NP40, Triton X-100, Orvus, or Tween20 are recommended by many experts for cleaning gravestones. These chemicals are electrically neutral cleaning agents that neither contain or contribute to the formation of soluble salts. They are neither soapy (normal soaps are Ionic detergents), nor do they affect pH. By decreasing the wash water's surface tension non-ionic detergents reduce droplet formation on the stones surface. In general they have been proven to provide a better overall wetting of the stones surface that other detergents and as a result, produce better results in the removal of general soiling.
Non-ionic detergents are available from conservation, janitorial, and photographic suppliers in various sizes. You may want to bring a small spray bottle of water for gently cleaning dirt and debris from the stone. Wash stone with solution, then rinse stone with clean water.
- Soft-bristle brush
Metallic brushes are entirely too harsh, and they also leave particles on the surface of the stone that can rust.
- Small, soft, slanted paintbrush - To clean debris and critters out of lettering or carvings
- At least one large sponge
You may also want to bring a small spray bottle of water for gently cleaning dirt and debris from the stone. The spray bottle, should contain only water
and not detergent or chemicals of any kind that would damage and further erode the stone's material. You might want to use Photo Flo, a neutral PH detergent which is made by Kodak and used in photo developing. It will clean the stone without affecting the chemical balance of the stone. Mix one capfull per gallon of water. A 2 gallon garden spray bottle can normally do several stones if used properly. Wash stone with solution, then rinse stone with clean water. Use brush
- Towel or old rags
Used to kneel on or clean polished granite stones. Launder them first, but do NOT use fabric softener. The softener will affect their ability to absorb liquids as well as cutting down on the "magnetism" for dirt and dust.
- Hand cleaner
Bring along a sample size of antibacterial waterless hand cleaners or wipes.
- Cutting Tool - Hand-held grass clippers, scissors or a retractable razor knife for trimming grass and/or weeds close to the stones. Do NOT use weed whacker type trimmers as these can scar the stones. For site clearing/cleaning, a pair of pruning shears or hedge clippers is also helpful for brush that is too thick to rip out or cut with grass clippers, but not thick enough to bother with a chain saw.
- Pencil and Notepad to record information about the stone or cemetery location.
In addition, you will want to also look at taking along the following safety items:
- Drinking water - plan to bring at least several quarts of water with you for drinking , apart from the water you use for washing the stones.
- Gloves - Both work gloves and rubber gloves.
- Work Boots
- Long-sleeved shirt
- Insect repellant
- First Aid kit
- Snakebite kit
- Bee and wasp spray
- Cellular phone
- Safety goggles
- Antibacterial liquid soap and or waterless instant hand sanitizer
- Protective hand lotion
- IvyBlock (for poison ivy, oak and sumac)
ABOUT STAINS AND STAIN REMOVAL
- Before you attempt to remove a stain, it is extremely important to know what has caused it. If you don't know, it is highly recommended that you consult a stone specialist
- Avoid using chemicals of any kind until you know which chemical cleaner to use. Certain chemicals will react with the spilled material, and could make the stain permanent.
Removing stains from marble or granite can prove difficult. These stones are porous materials, and If not thoroughly sealed they we be susceptible to staining. The only way a stain can be removed is to use a safe chemical that will pull it out of the stone and an absorbent material that will soak up the stain. This chemical absorbent-material combination is commonly referred to as a poultice.
Poultices are commonly powder or cloth materials that can be mixed with a chemical and placed on top of the stain. Refer to the table below for some of the more common poultice materials. Clays and diatomaceous earth are safe and readily available, but do not use whiting or clays containing iron with an acidic chemical; iron will react with the acid, and may cause rust staining. It is best to purchase powders that are designed specifically for stone and tile. Consult a stone restoration specialist or your stone supplier if in doubt.
Paper towels Cotton balls Gauze pads Clays such as attapulgite, kaolin, fuller's earth Talc Chalk (whiting) Sepiolite Diatomaceous earth Methyl cellulose Flour Saw dust How to apply a poultice
To apply a poultice, take the following steps:
1. Clean the stained area with water and stone soap. Remember to blot rather than wipe.
2. Pre-wet the stained area with a little water. Distilled water is recommended.
3. Refer to the chart and determine which chemical to use for the stain.
4. Mix the poultice material with the selected chemical. Mix until a thick peanut-butter paste consistency is obtained.
5. Apply the paste to the stained area, overlapping the stain by at least ¼ . Do not make the application too thick, or it will take a long time to dry.
6. Cover the paste with a plastic sandwich bag or food wrap. Tape the plastic using a low-contact tape.
7. Allow the paste to sit for 12–24 hours.
8. Remove the plastic cover and check to see if the paste has dried. If it has not, allow it to sit uncovered until thoroughly dry.
9. Once it is dry, remove the paste by scraping and rinse the area.
10. Examine the stain. If it still remains, but is somewhat lighter, re-poultice until it is gone. If the stain refuses to disappear completely, it is time to give up, replace the tile or call a stone specialist.
Stain removal can be very difficult, and care must be taken when using a poultice.
(The above information from The National Training Center for Stone and Masonry Trades)
- Practice on a rock at home, or check with a local monuments store to see if you can practice on one of their tombstones, before going to the cemetery.
- In the case of cemeteries located on private property, remember that you are doing rubbings on someone else's property. It is ALWAYS advised to gain permission by attempting to speak with the property owner, and explain want you want to do, BEFORE you begin. If you do not get permission, please respect the wishes of the cemetery and ask if you can take a photograph to record the information and condition of the stone. If you find that a gravestone is severely damaged, please notify the property owner or supervisor of the cemetery.
AT THE CEMETERY
- Before starting, all surfaces of the stone should be checked. If there is any question as to the stone's condition, do not attempt to clean it, as the surface could be irreparably damaged in the process.
- Start with a test patch of your proposed cleaning technique on an area of the structure that is least visible.
- The stone surface should be thoroughly pre-soaked with water.
- Thoroughly wash with plain water the pre-wetted stone with natural, soft bristled (natural or nylon), wooden-handled brushes of various sizes. The use of plastic handles is not recommended, as colors from the handles may leave material on the stone that will be very difficult to remove. Wire brushes, metal instruments and abrasive pads may give you instant satisfaction but, if you clean with anything that is harder than the stone, you risk scratching the face of the stone and causing more damage in the long run. Be thorough. Wash all surfaces. Scrub the stone from the bottom up to avoid further streaking and staining. Always watch carefully to make sure that none of the stone’s surface is eroding as you scrub. Rinse thoroughly, with lots of clean water.
- Keep the stone wet at all times; really wet. Where a garden hose is not available, be sure to bring plenty of jugs of water and keep dousing the stone as you work and, most importantly, flush the stone well when done.
- Remove bird droppings, dirt moss, lichen etc. from the stone if possible. This will insure clear and sharp copy. If lichen is a problem, you can scrape with a wooden or plastic scraper. Tongue blades or craft sticks work well. Also, inexpensive plastic putty scrapers from home stores work well. Remember, no metal. If you have any trouble getting any of these materials off the stone, STOP and be sure that you do not cause any damage the stone in your attempt to clean it.
- If used, do not allow detergent solutions to dry on the stone while cleaning.
- Some stains in porous stones cannot be removed. Do not expect the stones to appear new after cleaning.
- Do not clean marble, limestone, or sandstone more than once every 18 months. These types of stone may occasionally be rinsed with clean water to remove bird droppings and other accretions. Granite can be cleaned as needed.
- Keep a record of the cleaning, including date of cleaning, materials used and any change in condition since last cleaning (such as missing parts, graffiti, and other damage). These records should be kept at a central location where the condition of the stone can be monitored over time. Saving Graves will be happy to store this information as a part of a cemetery protection association listing.