Why the milky-colored water from washing the roof of my motorhome?

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

rsalhus

Well-known member
Joined
Jul 20, 2006
Posts
1,335
I take a rag and a pail of hot water with a little soap in it and go up on the roof of my motorhome and hand wash it.? I rinse the rag frequently and the water gets all milky-colored, especially the front cap area.? I also get some white milky-colored streaks down my windshield and the sides of the motorhome when water runs off of the roof (when there is heavy dew or a light rain).? Something on the roof surface is reacting with the water to turn milky-colored.? What causes this and what can be done to prevent it?
 
I have the same thing with our 2003 Monaco Camelot (plain water is enough, doesn't need to be hot and doesn't need soap). I didn't get a straight answer on this issue when I talked with the folks at the Monaco factory service center. I've been trying to decide whether to apply some kind of protectant up there, but I don't want to create a slippery/dangerous surface.
 
I put a coat of Gel Gloss (one step cleaner and polish) on the front cap of the roof today after washing it and letting it dry.? We'll see if that helps at all.? Yes, it is slippery, so you have to work from front to back and outside to center.? I have a feeling if I wash it again tomorrow it will still turn the water milky-colored.? ?:mad:
 
Rolf, FWIW my caps aren't white, but the main part of the roof is. So my caps aren't giving off the white stuff. I have a tough time with heights at the best of times, so I doubt I'll be applying anything that makes it slippery.

Looking forward to hearing how yours works out though.
 
Tom  My Pace Arrow did the same thing.  I think most with rubber roofs do.  I put 3 coats of the roof coating on last summer and the chaulking ceased.  Thought we had this conversation couple of months ago be then I could be mistaken .    Not saying 3 coats are needed but I had the Material so I did it.
 
My whole roof is white and is supposed to be made of fiberglass. ?But the roof cap is smooth and slopes to the front, so that is the worst part to make slippery. ?I don't walk on the front cap, I just crawl around on that, but slipping off from almost 12 feet high doesn't interest me in the least either. ?The rest of the roof has some type of structure pattern that gives me some traction to walk on. ?But I think I get more white milky-colored streaking from the front cap than from the rest of the roof. ?I'll let you know if the Gel Gloss works, but I'm not holding my breath. ? :p
 
Shayne,

My roof is not rubber. Like Rolf's, it's apparently fiberglass, but I've never seen fiberglass give off this milky stuff before.
 
Thanks Rolf. My front cap is brown and sloped. I stay off it altogether. The main roof has a traction pattern running along its length on each side, enough to make it tough to clean but probably not enough to prevent me from slipping.
 
That "Milkey stuff" is most likely titanium dioxide (The white pigment in paint)

It is called chalking and it is how paint, and selected other finishes, keep themselves clean  Just like your body the top layer sluffs off carrying the dirt with it.  This is why if you brush up against the side of your house you get a white powder on your cloths/arm/whatever
 
Didn't see earlier where it was Rubber or Fiblerglass, hench the nature of my statement.  Now that it's stated to be Fiberglass,  I agree on the gell and lots of waxing.  then I'd switch to Dri-wash or Protect-all.  Just my Opinion.
 
Shayne said:
Didn't see earlier where it was Rubber or Fiblerglass, hench the nature of my statement.

Understood Shayne. That's the challenge of writing - it's too easy to assume the reader "knows" what I'm talking about. I've walked on the roof a number of times, but you've never seen it, so there was no way you could know if it was fiberglass, rubber, or any other material.
 
Hi John. I wasn't previously thinking about a painted white roof. It sure looks like gel coat but, on reflection, there's no way gel coat would still look the way this does after 2.5 years in the sun. I'm going to take a closer look this morning. Should be able to scratch a small area and determine if it's paint or not.
 
House paint is designed to chalk, RV paint isn't supposed to do that.
 
Ned, I would think you're right. I've never seen any chalking from the (brown) painted sides, front, rear, or caps of our coach. OTOH titanium dioxide is probably used for the white pigment in the white paint on the roof. I'd never heard of this problem until I first saw it with our coach.
 
FWIW here's the prior discussion when I first reported this problem with our roof.

It's not industrial fallout - there is no industry around here. Plenty of farms though and they deposit peat dirt over everything. But that stuff looks brown on the surface and actually looks black when it's wiped with a white terry towel.
 
Could be that titanium dioxide is used in the paint, but it's a hard finish paint, not soft and designed to chalk like house paint.  The TiO2 is just for the bright white color.  I have to think it's something other than the paint causing it.
 
Ned said:
I have to think it's something other than the paint causing it.

There's nowt else up there that's white Ned (except the King Dome, which wouldn't explain the white stuff coming down the length of the coach) ???
 
Shayne, I read in your post that you put three coats of sealer on!!
What exactly did you use??
My Pace Arrow has a rubber roof and would like to take care of it!!

Thanks Randy
 
I went a Napa Store and got a gal of All Green Cleaner and scrubbed my roof.  From Camping World bought 1 gal of Kool Seal Rubber Roof Primer and 2 Gal for Rubber Roof Top Coat and Rolled it on.  Is the primer and then a couple days later the 1st coat of finish.  A few days later the 2nd coat,  and a few days later the 3rd coat.  I did use an old cheap brush around the sewer vent and A/C units and vents on top.  Oops forgot  I 1st used GeoCel sealant on the joints and around the vents before the Primer.  This stuff is around $55 a gal.  I'm very pleased with the final results.  I always said if 1 coat is good, 2 is better and, 3 is super.  This is just my way of doing this, others may vary.  Good Luck with however you do it.  All Green was like $8 gal and I only used about a Qu and a half.
 
Shayne,  Have you found a difference with the inevitable "black streaks"  Did this eliminate the streaks???
 

Forum statistics

Threads
131,753
Posts
1,384,366
Members
137,524
Latest member
freetoroam
Back
Top Bottom