I am on a job site right now working on a travertine project.  The installer had used sanded grout, then applied a color enhancer without getting all the haze off, then used an acid based cleaner to try to remove the haze and then sealed it with an impregnator...great, huh?  Well the travertine turned an orange (ish) color.  We removed the sanded grout, filled with an un-sanded grout, removed the lippage, grouted again, honed to 250 grit, grouted again, used a 400 grit honing powder and have been cleaning up.  We got rid of the orange color and returned the stone to its original color.<br>
<br>I noticed these black marks on the edges of most of the grout lines.  They are not gaps in the grout, they are black marks.  I have no clue where they came from.  What would you suggest I use to remove the marks? <br>
<br>Thanks All<br><br>Georgia Rivera<br>Stone Buff<br>