You may have sealed them, but either the sealer was not a good product like we carry or you didn't seal it properly or some type of alkaline solution got on it and basically dissolved the sealer.
In any case, we can fix this. The stain from the orange juice is not actually a stain, but rather it is the stone getting etched by the citric acid. Water will darken the stone while it is in there, but once it evaporates so does the stain, so I think the other stain is something else - maybe a water based liquid with color to it or oil from salad dressing. It doesn't matter because we can fix this.
Here is what you do. We are going to remove the stain with an alkaline solution of caustic soda and water. Mix it 10% caustic soda to 90% water. You can get this stuff at any swimming pool supply as it is what they put in the swimming pool when the acid level is too high. The first thing I would do is treat the spots with an alkaline solution to make sure all the acid is sucked out of the stone. You can use either caustic soda and water solution, or if it is a small area and you have Drano, use that. Drano is a great alkaline solution, I don't recommend it for large areas as it is a lot more expensive than the caustic soda. Put the solution on your stone and lay a paper towel over it to keep it moist for 30-60 minutes, then clean the stone thoroughly with water.
After it dries you may have lost your shine where the orange juice was. You can repolish it with Diaglo. Here is what you need to do for that:
Get a variable speed grinder, a backing pad, a felt wheel and some Diaglo polishing compound. Here are the links:
http://www.defusco.com/bosch-variable-speed-angle-grinder-p-2515.htmlhttp://www.defusco.com/flexible-backing-pad-velcro-p-1939.htmlhttp://www.defusco.com/alpha-felt-wheel-velcro-back-p-2360.htmlhttp://www.defusco.com/diaglo-dark-granite-1qt-p-1453.htmlNow put the felt wheel onto the backing pad and screw the backing pad onto the grinder. Turn the RPM down to position 1 or 2. Sprinkle some of the polishing powder over the areas you need to repolish. Mist over with water. Use the felt wheel to turn the powder/mist into a paste. Buff paste over the area (similar to buffing a car) until you have the desired result. Remember to keep the paste a little moist. You may have to do this process more than once to get the desired results. It depends on how high a polish your slab has and how much the stone was etched.
When you are finished with the polishing, wipe on the Hydrex sealer to impregnate the stone. This will stainproof it and prevent citric acid (and other acids) from etching it. It is a mineral based sealer so it will last a long time. I used it in my shower 5 years ago & it still makes the water bead up like day one. I am not familiar with surface guard, but apparently it doesn't work very well or for very long.
http://www.defusco.com/tenax-impregnator-and-sealer-liter-p-2095.htmlIf you have any questions please call me at 800-289-6834 during the day.
Glad to be of service,
Mark
