I seem to be having a problem (recurring) with some spots on a light grey nylon carpet. The initial problem was when the roofers got some tar stains on the carpet and I cleaned the spots with POG. Unfortunately for me the spots went away and I was left with what appeared to be a residue stain. I used an acid rinse with hot water used a portable extractor. Hot water was used from a coffee machine. This worked for a bit but the dark spots came back. I then used my extractor with hot water only no chemicals, and lo and behold they returned. I spoke with my supplier and they said that I might still have some residue from the tar. The fibers are dry and their is no evidence of any residue. I tried to use an oxidizer again no luck. What would you recommend for my next step.
You’ve done quite a bit with this spot… good to see the dedication! The next step? There are several other things you can do, but for me, I’d try a good gel solvent with lots of flushing. Has to be residue if the spot is gone but then returns darker, like it is attracting soils over a period of a few days.
I’ve found that POG works well but does often leave a residue. And sometimes, as your supplier contact indicates, there could be some residual tar remaining as well. Either way, another cleaning is warranted and you need to ensure you remove all the tar plus any greasy, soil attracting residue. So while you could use a volatile dry spotter, I recommend a gel that will flush out with super-hot water and detergent.
Try that, and after cleaning, put a little encapsulant spotter on it, according to directions. It will limit resoiling. Or, if you don’t do that, put a white, disposable cotton towel on the damp spot and put a weight on it, like a gallon milk jug with water in it, so any recurring spotting substance or residue might go into the towel.
Even better? Do both - the encapsulant spotter plus the weighted towel (also referred to as a "poultice".)
Let me know how it goes…
The Cleaning Professor