Restoring marble gravestones that have been on ground for 80 years. O K to use bleach? Or?

Question

I have 20 gravestone that were broken off and left on the ground for all those years. They are black with fungus and dirt.

Will the bleach hurt them? I intend to build new bases for them and return them to their origonal location, which I have marked. The graveyard has been abandon for almost a century.

Answer 1

Start with just water and a little dish detergent.   Bleach will damage the surface.

http://www.realsimple.com/realsimple/con...

Added as an edit - I think this is the wrong link.  It's for limestone, not marble.

You are working with historic artifacts in addition to  religious icons, and really shouldn't rush or try to do the job "on the cheap."  Bleach will interact with the surface and possibly damage the carvings that are there.

This is a better link to "how to" from "hints from Heloise"

http://www.goodhousekeeping.com/home/hel...

Answer 2

Power wash. You can try bleach. if that don't work try a little weak muratic acid.Experiment with the side of one first. Your a good man, their spirits will appreciate it.

Answer 3

Marble is so porous that it seems unlikely that you can do a good job with anything---it's not a DIY project.  Contact a stone supplier and get professional information.

Answer 4

The link below advises NOT to clean, but if you have to has tips on doing so.

The second is how to as well & says not to clean them more often than every 18 months using water only - no ohter chemicals.