Removing Tar from FRB walls?

[Rudy]

Two days after acid cleaning my FRB walls, some idiot sprayed some coal black tarry substance all over the place.

The mess appears to be petroleum based. Tire cleaner doesn't make a dent. Acid wall cleaner doesn't make a dent. A rag dipped in either gas or kerosene makes only a LITTLE dent in it. I think the stuff may be asphalt sealer or similar.

Anyone got any ideas how to clean this?

 

[JustClean]

Give it a try with WD-40. That works well on cars with tar and shouldn't damage anything.

 

[JeffM]

Maybe try a citrus based solvent degreaser?

Found this on a quick search..

http://www.smartjan.com/sss-13062-sss-orange-plus-hydro-citrus-cleaner-degreaser-gallon-bottle

 

[MEP001]

You can get the Zep orange degreaser from Home Depot for about $12/gallon. It will break down tar easily if you apply it straight and use a stiff brush on it.

 

[dogwasher]

Mineral Spirits