blue stone with rust stains

Q. We had bluestone installed outside. 2 months later we see rust like circles that seem to be almost indented. we have not used fertilizer or salt near this area.. installer is perplexed ..could it be "defective" or low quality?

 

A. I have seen this myself several times and still not sure what causes it. I don't think it has to do with the quality.

 

I use a product called nu-stone cleaner and an acidic cleaner for rust. we also used a series of nylo grit brushes and it seemed to work. Wouldn't be a bad idea to call a bona fide stone refinisher who could run a few tests and maybe solve the problem.

 

You can find one in your area at www.stoneandtilepros.com (Find a PRO).

 

Stu Rosen