The problem sounds like you have a light etching, suggest honing the spots to see if they come out. You will probably find out something the previous company did etch these spots. Now you get to fix them.
Depending upon the etch I would start at a 220 hone , then do a 400 , 800 and polish. Don’t be concerned with it blending with the other stone, if you get a good hone and feather out the area you hone should blend with no problem.
The reason I recommending a 220 grit and not a 400 grit keep in mind that 5X powder has a grit in it that is between 400 and 500 and it the 5X did not remove the etch then you need to drop down to a 220 grit
I would do this wet, if you hone it dry how are you going to handle the dust issue? Wet mean you only need to wash down that part of the wall. If the dry becomes an issue you will need to clean the entire building. Amazing the amount of dust one creates when dry grinding .
John Freitag ‘
The Stone and Tile School
If it is light etching, just take 400 sand paper and 5X.
You should have no problem matching the finish. If 400 does not work, drop
down to 250 then 400. If concern about matching the finish, try a test spot!
I am having some trouble with a job I am currently on. Part of this job involves Botticino walls. (About 2000 square feet) There is some type of streaking from something a previous contractor put on it. I have no idea what it is. There are only about 10 spots on the walls where this is present but the customer is not happy and it needs to be removed. I have tried powder polishing to remove them (MB12 and 5 X) with no success.
I am wondering if I should try honing the stones where this is occurring,and then repolishing, but I am afraid that the new finish on these stones, while removing the streaks, will be different from the finish on the rest of the walls. Also, any thoughts on if honing is an option, could I do it dry ????
Any suggestions appreciated.