Getting black marks off 1990 Classic Fiberglass
 

I used Blue flat 3m no scratch scrub pads that I purchased at Home Depot. I wet the RV and then scrubbed with bar keepers friend. Rinse well.Dried with old towels and applied Protect All with caranuba wax. No wax chalky residue noted. Just a clean shine. The protect all polishes.waxes.treats.Protects. It even has UV blocker and is good for multiple surfaces. I comes with a 100% satisfaction guarantee. 98% of the black marks came out. My arm is just a little bit sore. Worth the effort.

Can't go wrong with BKF. Keep the pad and BKF handy so you can clean ours when we are up your way in August or September.:D

Removing black marks from our 1990 Classic
 

Bar Keepers Friend can be purchased at Walmart for $2.00 in the cleanser isle. It has multiple uses. One thing I would do differently is to wear gloves. The BKF makes your skin peel. Gary I wouldn't deprive you of the satisfaction of making your HiLo shiny. The each long side took about 1&1/2 hr. to do. If anyone gets to Niagara Falls send a PM and we will show you the sights if we aren't out camping.

Well, I had to try!:)

We have a 1990 also. We used BKF and a ScotchBrite pad to remove the black marks, but followed up with ZEP floor maintenance products.... wax stripper, followed by a coat of sealer, then two coats of floor polish. Once we were finished with the BKF the rest was fast and easy and the results were impressive.

I have heard of the zep floor treatment to coat RVS
 

Dh has done professional janitorial for a living. He wonders about how hard it would be to strip it. We ended up with a nice shine with our protect all wax.

I haven't tried to strip it yet, but I don't anticipate a problem. I have used Zep products in the past (basement tile floor) and they have always worked well, so I think the Zep stripper will do the job when the time comes. I hope that stripping will not be necessary though, since no one will be walking on it and I will maintain the shine with Zep floor cleaner. The Zep has worked so well on the trailer that I plan to use it on my boat as well.

Using Zep floor wax
 

I read on another forum that when the treatment looks a little shabby just add additional coats.

Have you tried Awesome from the dollar store? It sure worked for me- then of course rinse good and wax.