Painting the roof white

[marigold]

Ok, I have made the leap from a dark blue roof to a bright white one using elastomeric coating. I put down two coats of special primer and two coats of the white topper and I'm kinda over it.

My question is this, will I get significantly more heat reflection by adding more coats or no? I'm itching to get that painters tape off, but I have enough paint to do a few more coats, does anyone have experience with this elastomeric stuff? Thanks!

 

[gypsychic]

Oh I'd love to see pics and know what the special primer is. I also have a dark van and was wanting to do this. Would like any other application tips you can think of.

 

[WheelEstate USA]

Yup, got it on our white van. I found you have to get rid of the original paint or eventually it will peel off down to the factory primer.

It does help and really mutes heavy rain too.

 

[Wabbit]

Here's a link to what some school buses use. A gallon would be enough for a vans roof.

http://www.hytechsales.com/prod2150.html

 

[marigold]

The product I used is called sno roof elastomeric roof coat and it has its own primer or "underseal" as well. there are other brands out there, just look for the word elastomeric and read the specs. I cleaned and scuffed the underlying paint, sealed the seams with a rustoleum sealer, did two coats of primer and two coats of the topper. Sorry the pics are sideways! Hopefully it will stick and reflect.... it does feel way cooler in here already parked in the sun on a hot day.

 

[SternWake]

I hear you on Being 'over it'. I've painted more coats of white paint than I care to think about on my roof.

The heat reflection by more coats will be immeasurable, however winter heat retention will be increased to some degree, if that is a consideration for you.

I do not have experience with the elastomeric stuff, I wonder if too much is undesirable as the thicker the coating, the more resistant it is to elasticity and perhaps might peel away from the substrate after lots of heat cycles.

Sometimes these products will cure in the Can too, so any unused portion will soon become forever unusable. I've taken to displacing the air in half cans of paint with Propane to keep them from skinning off.

if you have the weather for safely applying more coats, I'd say just use it up. Application is easy in comparison to the prepwork for application.

 

[marigold]

Hmm, well the guy at the hardware store said if I used the primer I didn't have to take off all the underlying paint, but who knows, he could have been selling me a story... and an extra product we will see.

 

[gypsychic]

I was thinking I'd have to go down to bare metal before adding the elastomeric coating. Probably should on my van anyways as the paint is peeling in places. Plus I have some rust issues on a small portion of one of my rain gutters that needs to be attended to first.

Did you put it on with the broom in the bottom pic? That's interesting. I was thinking a roller.

Forgive my ignorance, but what do you mean by seal the seams with rustoleum?

About how long did it take to do? How long in between coats? Since I don't have a place to keep it out of the elements I wanted a general idea so I could plan.

I've heard of Henry's mentioned on here before. I'll look into the snow cap.

Thanks so much for your info!

Binding&us - good to know that it helps even with white vans.

 

[WheelEstate USA]

I used a brush to smooth the material into the grooved portions and foam roller on the rest.
I didn't tape but went right into the gutter with a lighter couple coats.

Compassrose was telling the other day about how she sandblasted her bus roof before applying the roof coat.

 

[marigold]

Lol, no I put it on with a roller that broom was for sweeping leaves off the roof!

The roof of my van has a few seams where the metal panels meet and some were leaky; and rusted so I sanded the rust off and sealed them with a product by rustoleum called flexible seam sealer (or something, I threw away the bottle).

I'm on day 3 so far, waiting between 3 and 6 hours between coats and I gave the primer a full 24 hours to dry before putting the topper on.

As with every project it's taking me longer than expected.

 

[gypsychic]

On a small phone screen, the sunlight on the broom ends look white...[emoji57] [emoji4]

 

[marigold]

Ha, yeah I see what you mean there, you never know, people get creative!

 

[ccbreder]

Important to read and follow any thing printed on the paint can. Don't rely on clerks.

 

[highdesertranger]

thanks marigold. let us know if you notice a difference in the inside temps. highdesertranger

 

[flying kurbmaster]

just thinking out loud, why don't you use the rest of the paint on the cab roof or have you already painted that?

 

[marigold]

Yeah, I thought about doing that but I like it blue too much.

 

[compassrose]

If you have a clear coat on your auto, then the roof coating probably won't stick (it didn't on my Jeep). After the first rain, it just peeled off in huge pieces. But it did make a huge difference in temps (my jeep is dark green). That one was Snow Roof. I had it left over from using it on the Class C. Henry's is what I used on the bus.

The roof coatings are not "paint".

 

[gypsychic]

compass rose - since you've used both snow roof and Henry's, did you notice and difference or have a preference for one over the other? I'm going to prep my dark van roof next week if the weather cooperates. Would love to hear your thoughts about difference or sameness of the 2 products.

 

[marigold]

Hmm, compass rose did you sand your jeep before laying down the roof coat? I did, but maybe not enough it looks kinda like it might peel off. I followed the directions on the can to a t...

 

[SternWake]

compass rose - since you've used both snow roof and Henry's, did you notice and difference or have a preference for one over the other? I'm going to prep my dark van roof next week if the weather cooperates. Would love to hear your thoughts about difference or sameness of the 2 products.

I have never applied Henry's to metal, and have not worked with their white product, but I have applied various types of their sealants to both dry porous wood and to wet hard woods, and the adhesion of product to substrate is not impressive.  If it is not abraded it is fine.  Like when putting treated dried and henried 4x4 fence posts in the ground and filling in the hole with concrete, the concrete can  easily scrape the Henry's off the 4x4 when shovelled into the hole.

I used premuim Yacht enamel to paint my roof, and the prepwork is key to final result and adhesion.

If the surface needs to be sanded, make sure to wipe/clean the area first with a solvent.  otherwise the sandpaper pushes any wax, or clearcoat or contaminant deep into the scratch marks and this inhibits adhesion to some degree or another.

They rarely include this morsel of info in the directions.  Always thoroughly clean before busting out the sandpaper.  If water beads, then there is still contamination which will inhibit adhesion.

If one sands to bare metal, then some Ospho applied preps and etches the metal for maximum adhesion, but don't let it get wet for 24 hours.

If one applies to a painted surface, the adhesion can only be as strong as the adhesion of the original paint to the primer below, or of the clearcoat to teh paint below.  

I imagine the solvent(s) which evaporate as the Henry's dries, can partially dissolve some paints or clearcoats and compromise adhesion too.

The primer the products insists on likely acts as a barrier to prevent the solvent from degrading the surface below.