How to clean fiberglass texture roof?

[pago cruiser]

I cannot believe there has never been a post on this?

With our monsoon just around the corner, I was going to re-caulk a few areas where the PO sealant was cracking; as much as 1/8" wide on the front and back top seams.

That stuff is a bugger to get off. But once off and re-applied, I want to go over the roof; it appears to have been un-coated since new, with the textured gelcoat "valleys" now filled with black grit. And there was no screw in the hole under the Dicor...



I have tried the eternal tape cleaner, as well as the Dicor fiberglass roof cleaner, as well as acetone, and a few other cleaners that Camping World and our local Lazy Days RV stores have. Nothing works.



Could anyone provide a hint of what works?

This stuff almost looks like mold: but this coach has been stored outside most it's life, with the last few years in the desert. Not much mold survives 120F. I can pick out teeny-tiny pieces of it with my pocket knife; literally, much smaller than a piece of ground pepper - we're talking fly-sh!t sized pieces...; but with almost 200 sq. ft. of roof I fear I would not get it done before I die...

I'm going to arm myself with some bleach, some ammonia, some gasoline, brake cleaner, "Goop Off", and whatever else I can find in our local ACE store today, as well as a couple different stiffnesses of plastic and bristle brushes. Yes, I am aware these things should not be mixed. Hm. That reminds me. I'm also going to get some Comet powdered cleanser; that stuff used to work great on really grungy stuff.

AND THEN... how the devil do you remove the old Dicor goop at edges of fans, etc that is also filling the valleys in the textured fiberglass? In the first pic, I rubbed (and rubbed and rubbed) a spot about the size of a quarter with a soft rag saturated with the Eternabond tape cleaner. It kind of worked... but my fingers are gonna be awful sore if this is the only way...

[pago cruiser]

Got over to the coach about noon, with a few armfuls of stuff. Dicor fiberglass cleaner, eternal tape cleaner, acetone, goop off, brake cleaner, gasoline, bleach. Was not able to try the comet, as I had no way to wash it off the roof. From what I tried, bleach was the best - maybe 20% effective.

Had to go into ACE for some hardware, and one of the "Helpful Guys" suggested this 30 Second Outdoor Cleaner - "The original since 1977". Personally, I had never heard of it.

Best tip I have had in a year. Took 2 applications, and scrubbing with a plastic bristle brush in various directions - but it worked fantastic. The ingredients say sodium hypoclorite and Tri-sodium phosphate (TSP). TSP is the stuff that if you wash your house rubber membrane roof with in order to apply a new coat, you have to keep a continual stream of water on the sides of the house, and the GLASS! This stuff draining down the window will literally etch the glass. Cleaned all the black crap off perfect; ready for paint.



As far as getting the old Dicor off, this is what I started with; I was able to stand up a screwdriver in the crack:


Here was in the middle: From what some folks at RV repair places have told me, "Dicor is made to be reapplied on top of existing". I call BS. Just like when adding a gallon of good gasoline to a gallon of ethanol gasoline that has gone bad: you do not get "less-bad" gasoline. You actually get MORE bad gasoline. Take a look at the "new" Dicor on top of the old. That dirt was carried there by water.



This was interesting:



"Hey Joe! Think I drilled the holes in the wrong spot."
"No problem Dick; just cover it with more goop. No one will ever know".


This took a solid 5 hours of work, not counting the trip to town.

Our local RV repair place charges $100/hour. If someone tried to tell me it took 5 hours to clean the Dicor goop off a fan base to get it ready to remove, I would call him a liar...

[gloran]

When I bought my 1993 33' LY it was always stored outside and my roof looked like your pictures. I went to a do it yourself car wash climbed up on the roof and power washed it at close range and it cleaned up very nicely. Once it is clean you can wax or treat roof as you prefer with other treatments.
If you go to the my photo bucket link, I have posted some pictures there.