Prepping RV roof for caulking

[dshinnick]

We have a 2005 motorhome with a fiberglass roof. I've been told by a couple of techs that it's time to re-caulk (Dicor) the seams on the roof. They mentioned cleaning the roof, so the caulk adheres well, but I'm not sure how to do that. Something like Simple Green? I was planning on taking a bucket of water&something up there and washing the roof with a soft bristle brush, and rinsing it well.

Thoughts? Suggestions?

thanks-

dave

[TechWriter]

DSDP Don wrote:
I don't know what type of coaches you guys have since you don't put them in your avatar, but next time you're looking at a Newmar, Monaco, Tiffin or any other diesel pusher, look at all the seems closely. They're all sealed with silicon that lasts for years.

Maybe on your 2014 Newmar, but the fiberglass roof on my 2001 Newmar was attached with something like plumber's putty, Sikaflex, and screws. There was no silicone involved.

I think some of the "silicone" products are actually rubberized silicone or a thermoplastic elastomer based sealant like EternaCaulk which looks exactly like silicone.

[RedG]

I know they use clear silicone rtv on all the body seams, but I don't think they use any rtv on any roof components.

[Bumpyroad]

John Wayne wrote:
Are you sure it's silicone, dicor and the others are made in clear.

yep, clear urethane based on mine.
bumpy

[John_Wayne]

Are you sure it's silicone, dicor and the others are made in clear.

[Deano56]

DSDP Don wrote:
I don't know what type of coaches you guys have since you don't put them in your avatar, but next time you're looking at a Newmar, Monaco, Tiffin or any other diesel pusher, look at all the seems closely. They're all sealed with silicon that lasts for years.

What makes your statements incredibly wrong, is that you can look at any coach on a dealer lot and see silicone, especially over each window!!!!

i have looked at plenty of coaches, including Newmar

[DSDP_Don]

I don't know what type of coaches you guys have since you don't put them in your avatar, but next time you're looking at a Newmar, Monaco, Tiffin or any other diesel pusher, look at all the seems closely. They're all sealed with silicon that lasts for years.

What makes your statements incredibly wrong, is that you can look at any coach on a dealer lot and see silicone, especially over each window!!!!

[Bumpyroad]

Deano56 wrote:
the only silicone I'm seeing on coaches is patch work that someone has done after the fact. Silicone will not take the long haul, if it would, car manufacturers would be using it in the joints too, its not good in direct sunlight continuously

X2
Don't see any on my RV.
bumpy

[Snomas]

John Wayne wrote:
If you have a white roof just clean the area with acetone get some 4' wide Eternabond and it will be the last time you have to do it.

X2 on Using Eternabond!!

[Deano56]

the only silicone I'm seeing on coaches is patch work that someone has done after the fact. Silicone will not take the long haul, if it would, car manufacturers would be using it in the joints too, its not good in direct sunlight continuously

[RedG]

There's a video on this page.

[John_Wayne]

If you have a white roof just clean the area with acetone get some 4' wide Eternabond and it will be the last time you have to do it.

[DSDP_Don]

I see some don't like silicone, but go out and check EVERY joint on the sidewall of your coach! From the windows to the moldings to the wheel wells, it is covered/sealed with silicone after it's painted.

For the past ten years many coach manufactures have been using eternabond to seal the front and rear caps to the main portion of the body.

[TechWriter]

dshinnick wrote:
I was planning on taking a bucket of water&something up there and washing the roof with a soft bristle brush, and rinsing it well.

Depends a lot on how your fiberglass roof is constructed. On my Newmar, the roof is a big rectangle of fiberglass that is overlapped and glued & screwed onto more fiberglass.

My roof had some "warped" fiberglass where water had entered so I had to re-glue & re-screw these spots first.

Anyway, I used a sharp wood chisel (be careful) to remove the old caulk and cleaned with an abrasive pad soaked in 409 cleaner. Finally, I wiped the seams with acetone.

Here are photos of my repair.

[hooligan]

Big concern with silicone is that once it is used, nothing will stick to that area again if the silicon needs to be replaced.