Sealing Stone over Previous Sealers – Yes You Can

Deep Cleaner for natural stone surfaces

Deep Clean stone prior to Sealing

We often get questions something like this:

“I need to re-seal my granite countertops, but I don’t know what sealer (if any) my installer used. Can you help?”

The short answer is usually YES, with the following caveat; make sure the stone does not have a topical sealer first (and read below for another qualifier). This is highly unlikely, as most stone sealers for polished surfaces are ‘impregnating’ sealers, or ‘penetrating’ sealers. The operative word denotes that the sealer is absorbed down into the pores of the stone, rather than laying on the surface.

Some types of stone like tumbled travertine, and natural slate, may often have a topical sealer on the surface. You can usually tell this fairly easily by looking to see if there are scratches on the surface, or if there is any noticeable peeling of the coating. Yellowing is a dead giveaway.

For countertops or floors, I suggest performing the ‘water test’ first. Simply take a tablespoon of water and pour it on the surface, letting it absorb for 20 minutes. After 20 minutes, wipe the area dry with paper towels or an absorbent cloth and notice if there is any visible darkening of the color. If the water was absorbed, it will almost always create a dark spot on the surface of the stone. If this is the case, then it is definitely time to apply a quality impregnating sealer.

Here is where it gets a bit tricky…if you wish to use a water-based impregnator, then you may have limited success. If your water test showed the stone drinking up the water, then no-problem, go ahead and use a water based impregnator. We suggest HMK S232 Water Based Impregnating Sealer. If your water test did show some absorption, but the water pooled on the surface then you may want to use a solvent based impregnator.

Prior to using any impregnator, it is best to perform a Deep Cleaning first to remove all topical polishes, waxes, light grease, and grime from the surface. Please see the following directions: Deep Cleaning of All Natural Stone

For optimal results, we suggest using HMK S234 Silicone Impregnator. This penetrating sealer will drive the protectant molecules deeper into the stone than a water based impregnator, because the solvent molecules are smaller than H2O (water).

In case you are interested to see just how well S234 performs, please see how HMK protected a granite countertop from a red wine spill HERE

Using professional grade impregnating sealers will help protect your stone surfaces, and your investment.

If you have technical questions or have a stain that you cannot remove, please email us HERE

Posted in Protecting Natural Stone, Protecting Stone | Tagged | Comments Off on Sealing Stone over Previous Sealers – Yes You Can

Removing Rust Stains on Granite

remove rust on granite

We have received several emails from people having issues with Rust Stains on Granite countertops particularly around sink areas.


What is not commonly understood is that most natural stone surfaces have some amount of iron minerals in the composition of the stone. Some types have more than others, and some colors have more than others.



If you have a gold colored stone, it is very likely that oxidized iron is exactly what has colored the stone. This occurs in many ways in nature, but essentially Rust leached into the body of a lighter colored stone, thus giving it the tint or color you desired. When these same minerals are continually exposed to moisture (water around a sink) then rust can be accelerate. Further, if you use vinegar to clean the counters, this mild acid (2.4 pH) will oxidize the ferrous minerals an cause rapid staining. In some cases, newly installed granite can begin to exhibit rust stains in months if improperly cleaned using acids.

Fortunately, most rust stains can be removed or greatly diminished by using a professional grade rust remover made specifically for natural stone. We recommend HMK R777 Rust Remover followed by cleaning/neutralizing with HMK R155 Intensive Cleaner. We offer these products in a Combo Kit.

These products are consumer friendly and can remove rust from all non calcium based stone. This product cannot be used on Marble, Limestone, Onyx or Travertine.

For more information about the R777 Rust Remover, please see product information sheet HERE

Note: It is essential that once you remove the rust stains, that you seal your stone with a quality solvent based impregnator like HMK S234 Silicone Impregnator.

If you have questions about your particular stain issue, please email us for professional advise at

Posted in Stone Maintenance | Comments Off on Removing Rust Stains on Granite

Preventing Rust on Bluestone Pavers

Photo Courtesy of Hamptons Masonry Design

Photo Courtesy of Hamptons Masonry Design

It’s no wonder why Bluestone is such such a popular paving material. When selected and installed correctly, it looks amazing.

Unfortunately, one of the hidden problems with Bluestone is that there are ferrous minerals incorporated into the composition of the stone, which often turn into Rust Spots. These spots can most often be prevented using a few preventative measures.

Most importantly for installers and masons, NEVER use Muriatic Acid to clean cement and grout residue from the stone. Unfortunately, many masons learned that they can quickly and cheaply remove dried cement from stone and brick using Muriatic Acid which costs less than $10.00 per gallon, and it is a very caustic and effective cleaner of cement residue. However, like all acids, it is an oxidizer of metals. It is particularly harmful to Bluestone, as we have had many customers calling us with horror stories about damage.

In many types of natural stone, and Bluestone in particular, rust is inherent in the composition of the minerals. When exposed to moisture, and particularly when exposed to an oxidizer like Muriatic Acid, it accelerates the growth of rust and it begins to leach out onto the face of the stone. (see image below)


In some cases, the rust can be so severe that individual stones need to be removed and replaced. We always recommend the least aggressive cleaners, and progress, if needed to acids to minimize harming the stone, or changing the look of natural stone, particularly Bluestone. We suggest cleaning grout residue with a non-acid cleaner like HMK R155 Intensive Cleaner.

Secondly, and very important, is to protect all natural stone with a professional grade sealer. Solvent based impregnators work best and stop  the acceleration of oxidants. Impregnators come in two types, Invisible and Color Enhancers. For exterior applications, and to get exceptional results I suggest HMK S31 Silane Impregnator. To obtain a deeper and richer color, I suggest using the HMK S42 Color Enhancer. For outdoor kitchen and food areas, for extra Stain Protection, particularly with oil stains, I suggest HMK S244 Color Enhancer Extra.

As a stone professional and contractor using and testing all the leading brands, HMK Stone Care System products (Germany) consistently provide superior results.

If you have a question or problem with your Bluestone, please email me and I will reply within one business day:


Posted in Deep Cleaning, Rust Removal | Tagged | Comments Off on Preventing Rust on Bluestone Pavers

HMK R155 is “Magic Juice”

155-USA-Produktbild-2014-150x150Harry P. from Tarzana, CA called the other day to tell us how marvelous the HMK R155 Intensive Cleaner worked on his marble shower that had a significant buildup of Hard Water deposits. He says the R155 “Works like Magic Juice”

Thank you Harry for your comments, and giving us permission to share your story.

We suggested the following treatment:

  1. Mix a solution of 1-Part R155 to 5-Parts water in a spray bottle.
  2. Starting at the bottom of the wall, spray the wall in horizontal strokes, climbing up the wall until the entire area is covered very well.
  3. Allow the solution to activate on the wall for 15-20 minutes (Same process for countertops) It is important that the surface stay wet with the solution. Spray more as needed.
  4. Scrub area with a medium stiff scrub brush for 5-minutes.
  5. Rinse very well. (Repeat process if necessary)
  6. Allow to dry for 24 hours before applying sealer.

It is important that after you perform a Deep Cleaning of All Natural Stone as prescribed above, that you Protect your stone by applying a quality Impregnating Sealer. We suggest using the HMK S234 Impregnating Sealer.

If you have stubborn hard water deposits, or mineral buildup, or are cleaning up grout haze, the R155 Intensive Cleaner is a very effective (non-acid) cleaner safe for all natural stone surfaces.

If you have a stone cleaning issue, please email us a description, with images if possible to and we will provide expert assistance.

Posted in Cleaning Stone, Deep Cleaning, Stone Maintenance, Tip of The Week | Tagged | Comments Off on HMK R155 is “Magic Juice”

Remove Etching from Marble


How Marble Etches

Marble is a beautiful and functional surface UNTIL it Etches!

Understand that all Marble surfaces are Calcium based stone that can be easily damaged by Acids and High Alkalies.

The photo above is from Edie Wadsworth’s blog Living in Grace -Living with Marble

In her article, Edie talks about the pitfalls of living with marble countertops. What I have found over the years is that people don’t understand a few simple cautions. Common household liquids can cause etch marks on marble surfaces:

  • Coffee (drips down coffee mug-etch ring)
  • Wine (acid) drips down glass also leaving etch marks & rings
  • Cleaning Products: Windex with Ammonia destroys marble
  • Cosmetics – many contain harsh ingredients

Removing Etch Marks

For minor etch rings and spots, a commercial polishing compound will help restore factory polish. I have used and recommended HMK P21 Polishing Paste for more than 30 years.



Using a soft cotton cloth, or Microfiber Cloth, apply a dollop on cloth and buff into marble etch mark. You must put some force into the buffing action to create enough friction to smooth out the etch marks. Buff off residue with clean area of cloth. Repeat until you are satisfied with results.

For severe marble etch marks that you can feel a rough texture, these will require more aggressive resurfacing techniques. I will follow up with a detailed post at a later date, but for now, please see this LINK


Impregnating Sealers DO NOT protect agains Acids…they work great to prevent stains, but not Etch Marks. You need a physical barrier to protect acids from damaging marble. After protecting marble (and all natural stone) with a penetrating impregnating sealer, you can use the P21 Polishing Paste (like a coat of wax) to marginally protect against etch marks, but you need to re-apply often to help provide protection.

For help with your Marble Etch Marks, please Email us or call 800-380-6881.


Posted in Restore Marble, Restoring Stone | Tagged | Comments Off on Remove Etching from Marble

How to deal with Stain Emergencies on Natural Stone Surfaces

The First Step is to NOT Panic!!

Help is on the way for cleaning spills and stains on Marble, Granite, and other Natural Stone

  1. Mix a solution of Liquid Dish Soap and warm water, much as you would to clean a greasy pot.
  2. Soak a washcloth in the solution, and lightly wring it out
  3. Apply the saturated cloth to the stain making sure stain is completely covered.
  4. Allow to dwell on stain for 15-20 minutes.
  5. Wipe up excess solution and soak washcloth in the solution.
  6. Repeat until stain is removed.
  7. If stain does not diminish, you may need to order a Professional Grade cleaner.
  8. Go to and order the R155 Intensive Cleaner.

Once you receive the R155, mix a solution of 1-part R155 to 4-parts warm water. Follow instructions above. Most stains will be removed with multiple applications.

For more detailed information, please email a picture of your stain, indicating what substance spilled on the stone, what date, and what steps you took to remove it.

You can also reach us Monday-Friday 9:00am-4:30pm Mountain Time at 800-380-6881


Posted in Stain Removal | Tagged , , | Comments Off on How to deal with Stain Emergencies on Natural Stone Surfaces

UPS Shipping Rates Increase in 2016

During Record Low Oil Prices, UPS Raises Rates for 2016!

Each December, we cringe to see what the rate increase will be for the following year. This year (effective Dec. 28, 2015) the average rate increase is 4.9%

We have absorbed these rate increases for years while continuing to offer Fixed Rate shipping ($9.97) on orders up to $99.99.

Take advantage of Free Shipping for orders $100.00 or more on Professional Grade Stone Cleaning and Sealing products for the worlds leading brand – HMK Stone Care.

If you have questions on what products to use, please email us or call 800-380-6881

Posted in Tip of The Week | Tagged | Comments Off on UPS Shipping Rates Increase in 2016

Homemade Granite Cleaner – Here we go again!

Last July I published an article about “Homemade Granite Cleaners”
WIKIHOW IS WRONG About Granite Cleaners!

The issue is these (well intentioned) solutions can actually harm natural stone surfaces, especially polished marble, travertine, and onyx because of the higher alkaline content and use of isopropyl alcohol.

Another very popular website offers a similar Homemade Granite Cleaner recipe. Nature’s Nurture offers a recipe that also contains dish soap (pH from 9.5-14.0) that is highly alkaline and can damage calcium based stone, and alcohol that can break down sealers and impregnators prematurely.

A natural, Green-Friendly alternative is HMK P324 Liquid Stone Soap. This biodegradable natural maintenance soap is highly concentrated, and one liter can maintain up to 8000 square feet. We suggest one capful in a 16 oz. spray bottle. Simply spray stone counters and wipe dry. This is a no-rinse product and will help preserve impregnators and sealers, not break-down the protection.

So doing the math, for less than $30 (with shipping) you can have more than 2 years worth of daily cleaning AND protect and preserve your expensive stone surfaces.

If you have questions about how to Clean, Protect, and Maintain all Natural Stone surfaces, please email or call us at 800-380-6881

Posted in Daily Cleaning, Stone Maintenance | Tagged , | Comments Off on Homemade Granite Cleaner – Here we go again!

10K+ Page Views of our HMK R52 Stain Removing Poultice for Natural Stone

Why do you think that we have had 10,254 page views of our (currently backordered) R52 Stain Removing Poultice for Granite and Marble?

Because granite and marble surfaces are not being adequately protected with professional grade sealers. We get calls and emails every day from customers who “had their granite sealed”, but still have staining issues, particularly from oil spills.

See an Amazon Review of HMK R52 Stain Removing Poultice
Screen Shot 2015-12-04 at 1.43.32 PM

We have had so many orders of R52 that it is currently backordered until mid-January. Our Professional Grade stone cleaners and sealers are made in Germany, and even with the best order management systems in place, high demand has knocked us out of stock.

It doesn’t need to be like this if Natural Stone surfaces are protected with a professional grade Impregnating Sealer like HMK S34 Impregnator.

If you are experiencing stains in granite or marble that you cannot remove, please email or call us for expert assistance. 800-380-6881

Posted in Stone Maintenance | Comments Off on 10K+ Page Views of our HMK R52 Stain Removing Poultice for Natural Stone

What is an Oleophobic Stone Sealer?

“Oleophobic” (from the Latin oleum “oil”, Greek ελαιοφοβικό eleophobico from έλαιο eleo “oil” and φόβος phobos “fear”) refers to the physical property of a molecule that is repelled from oil.

When it comes to Granite and Marble countertops and other decorative surfaces, oil is the worst enemy. Even though many granite slabs are Resin Impregnated, oil can still penetrate.


Take a look at the picture here. Both pieces were “Sealed”. On the left with a leading brand that claims to repel both water and oils. The piece on the right was impregnated with HMK S324 Stone Impregnator.

Both pieces received a few drops of olive oil and allowed to sit on the surface for 15 minutes, then wiped off with a paper towel. As you can clearly see, the piece on the left has a visible (and lasting) oil stain.

HMK Stone Care products were developed in Germany and has been the favorite of Architects and Stone Professionals for more than 30 years. Choose wisely when looking to protect your natural stone surfaces.

If you have questions about HMK Stone Care products, please email or call us at  800-380-6881

Posted in Sealing Granite | Tagged | Comments Off on What is an Oleophobic Stone Sealer?