Saturday, March 09, 2013

Most often asked questions about stones in India

Most often asked questions about stones in India
Q1001: Dear Sirs, We require to rectify many leakage bathrooms after many years of work completion in a Condominium.
The floor and walls are installed with porous marble; your web advt. interest me to contact you. Marble porosity is the reason for leakage, very clear and hence looking for best way to seal marble. Can you please advise right product for us to use? Thank you. rgds, sara, Feb 13, Reply
R1: Dear Sara: Unless that particular marble was quarried on Mars, on planet Earth there’s no such a thing as a marble so porous that’s going to let water through to the point of creating a leak. If you check the grout and/or the caulking lines you will see that some of the grout and/or caulk are missing. That’s the “mysterious” porosity of the marble! Were those marble tiles installed “butt-joint”? If that’s the case, then the problem has no solution. Do you want to buy my impregnator/sealer, MB-4? Go ahead: Just don’t expect it to do the first thing to solve your problem. I wouldn’t want you to go on record saying that my product is no good!! :-) Ciao and good luck, Maurizio
R2: Dear Sara, Treatment of leaking bathrooms once they have been installed and that too in condeminiums is a very difficult task.
The two main reasons for these are faulty plumbing joints or porous covering.
In your case you have identified the marbleto be thereason for seepage of water.
It can be treated by two methods. Both involve different chemicals and differnt finising methods.
(a) If you can re-grind the stone then epoxy is is best. I would suggest consisting of Resin R-47 and Hardner R-46. These are mixed in 2:1 propotion and applied using a putty knife. After curing for 48 hours the stone will have to be re-grind.
(b) The alternative is to fill the porosity using a clear colourless impregnating sealer and after curing for 24 hours a top coat can be applied.
If you require any further details ,please get in touch which the undersigned. Arun
Q1: I am planning to re-do my kitchen. What should I choose for the counter. I have a choice between Marble and Granite.
R1. Ideally the kitchen counter in India should be of a non-porous stone as Indian cooking involves a lot of oil. Porous stones not only absorb oil and dust but also food particle and food juices which later on provide breeding ground for bacteria. It also retains odor.
I would recommend a granite preferably of a uniform shade like black or Red as they would clearly show spills and food particles. Mixed colors in granite appear dirty.
Granite is hard and will wear well and will be less susceptible to scratches. However if you insist on using Marble, the next best choice is Green marble. If you like a white top then use a fine grained marble and get it treated with a good epoxy sealer (food grade) before laying. Q2: Is granite suitable for flooring?
R1: Granite is hard wear resistant stone. This property makes it the ideal flooring material BUT the dust and sand leaves scratches and re- polishing laid granite is next to impossible. Scratched granite floor looks bad. Marble being a soft stone can easily be re-honed and polished. If the area under consideration is low trafic with minimum dust polished granite can be used. But be careful, if wet it can become dangerously slippery.
Un- polished granite (honed) or even flamed granite can be used. Other alternates amongst stone are Kota Stone, Bansi Paharpur (a variety of sandstone).
Q3: What do I use in a bathroom.
R1: A classical question with numerous alternatives. We will just concentrate on stones. I have seen practically all kinds of stone being used, right from Polished Granite to hand chiseled sand stone.
Ideally the bathroom surface should be fairly rough( recommended friction factor is 0.7 (anti-skid)) and non-porous. You can use un-polished granite, honned marble with epoxy filling and sandstone with epoxy and sealer coat. The details about the chemicals to be used can be provided.
Q4: I have a farm house where I have put up a lot of sculptures in stone in the open. How do I protect them?
R1: You can and should take of your sculptures. Some people want them to age. This can be best attained by leaving them untreated or by using specialty staining chemicals to give them an antique look.
Alternatively if you want them to retain their new look get them treated with suitable sealant and coatings. This will vary from stone to stone and we need more details to provide specific treatment.
Q5: I have marble floor in my house. The floor is stained . I have tried repolishing the floor but the stains do not go.
R1: Stain removal from stone is an art. The first step is to identify the stain. Is it oil, ink, paint, dirt, wine, coffee, rust etc. Etc.
Once the stain is identified special stain removal poultices are available to remove them. The older the stains the more difficult it is to remove them. It is best to get the stone sealed by an impregnating sealer immediately after laying it to prevent it from getting stained.
Q6: I have fixed a yellow Italian marble. It was looking good initially but within a year it has started developing holes and pits.
R1: You have used Travertine. It is a beautiful stone but it inherently has pits and holes which are normally filled using a mastic. Maybe in your case they just used pigmented mortar which is now coming out. Get it patched with a matching mastic and re-polished. It should last you a life time.
Q7: I like yellow sandstone. The one which comes from jodhpur, Rajasthan. Can I use it for cladding.
R1: Yes you can use it for cladding but you should pre-seal the stone as it is very porous otherwise with time you will have colored patches.
Q8: Which marble is the best?
R1: Which food is the tastiest? It depends on your choice and utility. It is very difficult to answer this in absolute terms.

Q9: We have an old marble fountain in our yard. We have been cleaning the salt scales using toilet acid for a number of years. The stone seems to be getting yellow and cracking. What should I do?
R1: You have been using the wrong method for cleaning. Acid (in your case hydrochloric acid) has been eating away layers of stone causing pores and pitting. The yellow stain is because of chlorine. Stop using immediately. Fountains like yours are priceless and should be preserved. Clean up the entire stone by using an alkaline penetrator. This will remove all traces of acid from the stone. Get the stone polished and sealed using an ideal underwater sealer.
Q10: We have used high quality green marble in our restaurant floor. We have started noticing a white powder coming out of the joints and the stone near the joints is loosing polish and becoming rough. The floor looks bad.
R1: It is efflorescence. You must be washing the floor very frequently. The water is going in through the joints (grouts) and dissolving the chlorides in the mortar. Normally the sand in the mortar contains chlorides. This causes the formation of a weak acid which starts attacking the joints as these are the weakest spots and here the stone pores are exposed . This is like a chain reaction . It is best arrested by reopening the joints and filling with a non toxic water based epoxy. If you want immediate results use High molecular weight polymer oils (HMWPO). Just apply this oil on the stone joints once a month and that sould arrest the problem.
Q11: I am planning to build a house in Bangalore. Where can I buy good quality stone at reasonable prices.
R1: Post your inquiry and I am sure a couple of Bangalore stone dealers will approach you . You can choose and negotiate.
Q12: I have marble mines in Rajasthan. I am looking for a financial partner. Can you help me?
R1: You will have to give more details on the quality, type of deposit and the kind of financial arrangement you are looking for. Post the details on the site and you may receive responses.
Q13: How do I find buyers for my stone. I would prefer export inquires.
R1: The answer is the same as for Q 15.
Q14. I have seen a number of interesting stones on your site. Can I get samples?
R1: I am sorry. We can not help you directly but you can contact individual suppliers / mine owners/traders and they may send you samples. They may also charge you for it.

Compiled by Fnd Stone Advice for the blog

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