Is the Verdict In? Does Painting the Roof Cool Things?

[J. Morgan]

Imo, the roof just being white is going to make the biggest difference.

A few weeks ago I bought a gallon of the Imron 3500 for less than $110.

You could paint the roof of an Airstream with a Half gallon no problem.

Whatever you use sand the roof well so it will adhere properly.

[JohnRFunderb]

OK, and Thanks!!

A few ideas: At about $110/gallon, that's $550/ 5 gallons; and I am hearing that it takes 1(+) gallon per 100 SF for ONE coat, and you need at least 2 coats, which is about a minimum of 3 gallons for 2 coats on a 22 to 24 foot length Airstream. So that's a $300 coating cost (3 Gallons), plus materials (rollers, plastic shrouding, roof wash/prep, etc.). So this roof coating is a serious decision, right?

It is very interesting that the majority of the 1920s to 1930s travel trailers (see "Trailerama" by Phil Noyes - 49 Travel Trailer Distributors!!) had WHITE roofs, (down to the window ledges). There really is no doubt that a good Bright White roof will lower indoor temps about 15 (+) degrees from ambient.

The real decision factor is the additional roof protection that the coating offers, and longevity of the coating, over how much time, against the costs/labor effort, for which product is best. I'm still trying to figure that out!! I am 60, and I only want to do this once, like you all (y'all) while I am agile!!

Ideas/Input?? Any great technical info is welcome!!
JF

[J. Morgan]

No, It took about a quart to paint my 31 footers roof.

The half gallon I mentioned above was generous enough to allow for way more paint than is needed.

There is a half gallon on this truck counting the inside of the bed. The stuff covers like mad.

This truck has one coat of paint.

[J. Morgan]

With five gallons I could paint two of these and have paint left over.

http://i245.photobucket.com/albums/g...5/DSCN0444.jpg

As far as durability goes, I painted the red trailer about four years ago, it still looks every bit as good as the day I took this picture.

If you sand the surface well, this stuff will stick, and I promise you it WILL last.

[J. Morgan]

If you look real close at this picture you can just make out the area that I painted my roof.

I had to compromise between shiny aluminum and painted area. If I had to do it over again I would paint further down the sides, not to the windows, but somewhere in between there.

When I lay one hand on the white and the other on the aluminum, I can tell a big difference in direct sunlight.

[Inland RV Center, In]

Originally Posted by J. Morgan

Imo, the roof just being white is going to make the biggest difference.

A few weeks ago I bought a gallon of the Imron 3500 for less than $110.

You could paint the roof of an Airstream with a Half gallon no problem.

Whatever you use sand the roof well so it will adhere properly.

Paint, applied to sanded aluminum, will not stay in place very long.

Sanding, very well, of course is a must, but then a good flexible primer must be used to assure longevity for the white paint.

Time, has more than proven that fact.

Andy

[J. Morgan]

I have 25 years experience that says sanding alone well does the job just fine.

IMHO the reason self etching primer is seen as essential is that OEMs prefer not to sand, and use the etch as a labor saver.

The biggest enemy of paint over aluminum is too thick of a film, this magnifies the problems of aluminum expansion and contraction.

The etch primer wont hurt anything, and in fact may help some with adhesion, but imo it is not needed so long as the aluminum is well sanded.
If used, it should be used in very very thin coats.

[Inland RV Center, In]

Originally Posted by J. Morgan

I have 25 years experience that says sanding alone well does the job just fine.

IMHO the reason self etching primer is seen as essential is that OEMs prefer not to sand, and use the etch as a labor saver.

The biggest enemy of paint over aluminum is too thick of a film, this magnifies the problems of aluminum expansion and contraction.

The etch primer wont hurt anything, and in fact may help some with adhesion, but imo it is not needed so long as the aluminum is well sanded.
If used, it should be used in very very thin coats.

Acids or self etching primers should NEVER be used on an Airstream.

The small amount of acid can and does get under the rivet heads, and in time, will eat through the paint and then you have a nice horrible water leak.

History has shouted that out for many decades.

Andy

[J. Morgan]

My mistake, I mixed up zinc chromate (and its modern replacements) with self etching primer.

Typing before thinking gets me sometimes.

But seriously, i have painted over bare but sanded aluminum for decades, it sticks well.

Of all of the trailers in the below link, and of many, many others not pictured, zinc chromate was only used on the red trailer.

That said, I did use it on the red trailer that I wanted to be "high end "....

But I didn't use it on the top of my Airstream.