What is the coating on my vintage C's roof?

[Willowleaf]

The 1977 Elkhart Class C I bought a few months ago has some sort of funky coating painted all over the metal skin of the roof. It is a chalky greyish white substance, looks like dried mud smeared all over and it is cracking around the rooftop protrusions like the AC unit and TV antenna base. The roof has a leak near the rear of the AC (i can feel the soft spot in the ceiling.) Can anyone tell me what this stuff is and what I can do about it? I doubt it is removable -- what would stick to it that I could use to recoat and seal the cracked areas? Or am I looking at having to tear off the whole roof and replace it with new metal and some sort of rubber sheeting? I have a bunch of 4" single-side Eternabond, but I can't imagine it would adhere to this mess. I will try to get some photos of it tomorrow to post.

If I had seen how bad this roof looked, I probably would not have bought the thing, but I'm too far down the road with it now, having rebuilt and re-skinned the entire cabover section.

[MartySQ]

Hi... I had much the same situation on my vintage '88 Honey.
I finally this year tackled it because we sprung a leak. I ended up buying a multitool (kind of like a vibrating scraper) and hired my son to climb up there and scrape all that gunk off... I didn't think it would come off, but the roof was aluminum underneath it with fiberglass sides, so it worked out ok... took him several days to get it finished to the point where it was clean enough to do something with. We then put eternabond on it. It got the leak. After the eternabond, we caulked with Dicor. Eventually I will paint snowcoat on it to help keep it cooler when we are boondocking in the summertime where there isn't any shade.

He had to sharpen the scraping blade a couple of times during the process because it would get dull pretty quickly.

Good luck. You may not need a new roof, but you certainly need to fix the leak and repair the damage it has caused underneath. Sometimes, the drain for the condensation gets plugged and the water must go somewhere... if it dips a little there, it could pool there and if the caulk or sealant was cracked it might have worked it's way inside.

[Willowleaf]

Wow, what a useful and quick answer! I actually do have one of those oscillating multi-tools (from Harbor Freight) and a bunch of various scraper blades for it. Wish I had an energetic son to do the work, so I guess that job falls to me.

I appreciate the tip on the AC condensate drain too, it makes sense.

the project will have to wait until this rainy spell ends. i have no garage and the RV has to sit outside with a tarp bungeed over it.

I figure I will have to cut open that soft section out in the ceiling to dry it out - hope it doesn't have structural rot and termites like the cabover framing did.