Black Streaks (Under window) up date

Have put Protect-All on the black window frames. That seems to take care of the black streaks occurring.

Must of changed formula, in old days it was abrasive, stopped using it due to feeling the grit and seeing the results on gelcoat.

Mainship wrote:
Soft scrub is abrasive and can take the gloss off gelcoat, you want black streak off not paint, if coach is blue paint whatever you use has to be safe for painted surfaces. If you are going to use abrasives Barkeeper's Friend is the least abrasive product. I would go the cw store route and checkout more black streak removers without abrasives and advertised as safe to use.

I think if you check it out you will find it says non-abrasive. Been using it for years.

Soft scrub is abrasive and can take the gloss off gelcoat, you want black streak off not paint, if coach is blue paint whatever you use has to be safe for painted surfaces. If you are going to use abrasives Barkeeper's Friend is the least abrasive product. I would go the cw store route and checkout more black streak removers without abrasives and advertised as safe to use.

I think I might have confused a couple of people. The streaks are not on the window they are underneath the window. The streaks are black the coach color is blue under the window, they are just under two windows the drivers window and the living room slide window. Roy

i use soft scrub,it is for cleaning showers and other household uses. it will take any wax off you may have but will take the black streaks off.

If the streaks are blue then the culprit may be windshield washing fluid. I replace my fluid with clear water only and remember to winterize the windshield washing reservoir by emptying the reservoir before winter.

You don't say how old the mh is, if it still has the original luster of new fiberglass or flat when cleaned and dry without wax, Blue sounds like it is a stain in the gelcoat or first layer of fiberglass, I have used bleach on bare fiberglass to remove the odd bird stain when they eat berries.

Do you wash / wax your RV regularly? If Awesome isn't taking it off I'm thinking there was a very light coat of grime that you've sealed in over the years with wax or polish (especially if you use a polymer wax).

The solution for fiberglass RVs is straight forward but a lot of work if, as you found, the one-step stuff isn't enough. You'll quickly realize just how big your RV is...

1. Wash, including the roof since this is where most of the dirt you see comes from
2. Meguiars Mirror Glaze #49 Oxidation Remover & Heavy Duty Cleaner
- this stuff is a light rubbing compound specifically made for fiberglass. It will take previous wax off as well as the trapped dirt and any oxidation you're seeing. They have more aggressive compounds but you likely don't need them (plus the take more work and remove more)
3. McGuires Marine / RV #45 Mirror Glaze / Polish
4. A good coat of wax. I like Meguires Flagship Premium Marine Wax

You don't need to use Meguires but this is what I use and it works. Others make similar stuff, just make sure you buy stuff made for fiberglass vs automotive clearcoat (usually says its for boats / RVs and / or airplanes). I suspect that once you do the black streak areas they'll look shiny and new, making the rest of the RV look like you gave up before you finished the job. If you choose to do the whole thing I suggest working in sections. If you've got lots of decals, graphics or vinyl decorative stripes you'll end up having to do a lot of the work by hand vs a polisher since the polisher can damage the vinyl. Good luck!

You could try some Greased Lightning. Use in a small area to make sure it is OK to use. Make sure that you wash it off with some soapy water and then wax if necessary.