Heat inside your bus, white roof vs other lighter colors?

[Clayton]

Great info! White it will be.

[boojiewoojie]

Again, add this to your normal paint of choice and you have Bus Kote: Fillers (3M glass bubbles)

[Versatile]

Originally Posted by EastCoastCB

It nothing more than elastomeric white paint with placebo beads mixed in.
The same paint at Lowes or HD is the same price or cheaper- for a 5 gallon pail.

What do they call it at LOWES or HD?

[boojiewoojie]

Cheapest is something like this:
https://www.lowes.com/pd/Valspar-Bar...-fl-oz/3083333

Lowes also says this is elastomeric: https://www.lowes.com/pd/HGTV-HOME-b...fl-oz/50404950

and then add the "placebo" beads:
Fillers The $9.95 pail should be enough for 5 gallons.

And again, here's my testimony on the beads:
I have several thousand hours driving white roofed school buses. When I painted my personal bus using the cheap 3M beads it made a noticeable difference. Did it show the difference with a thermometer? Maybe not but it was definitely noticeable. Could of just been having a fresh coat of paint but for $10 plus shipping I'm always adding it.

[EastCoastCB]

Originally Posted by Versatile

What do they call it at LOWES or HD?

Elastomeric roofing paint.
But I'd just seal the roof properly with seam sealer and paint it with flat white rustoleum. $25 a gallon and it will far outlast any elastomeric.

[oricha1984]

All you need to know about this topic is here:
http://www.skoolie.net/forums/f13/in...se-9291-5.html

basically the most economical option that yield best results: solarflex roof paint (multiple coats)
https://www.google.com/search?q=Sola...hrome&ie=UTF-8

[meteoricide]

Now I don't recommend this for a mobile vehicle, but I had a friend who was living in an old trailer in Las Vegas and he said the heat was killing inside most days. So I thought about it and came up with a solution that cost under $10 and made a 40 degree change inside that trailer on 100 + degree days. I bought 8 mylar safety blankets @ 80 cents each and a quart of contact cement - got up on the roof and glued the mylar down in about an hour. My friend was beside himself ... so was I to tell the truth when I felt the difference. Anyway true story - and DONT do this to your bus please!

[Iceni John]

Interesting. Those "blankets" are just aluminized Mylar, with virtually no thermal conductance insulation value at all. This shows that pure solar reflectivity does work, at least in this application. What's strange however is that a shiny aluminum roof gets very hot in direct sun. I still think that surface smoothness is very relevant to reflectivity - presumably an aluminum roof is still a microscopically rough surface even if it appears shiny, while the aluminized Mylar is smoother (even though it's probably also wrinkled and uneven).

I think that there's a lot more complexity to this subject than most of us realize!

John

[EastCoastCB]

Originally Posted by Iceni John

Interesting. Those "blankets" are just aluminized Mylar, with virtually no thermal conductance insulation value at all. This shows that pure solar reflectivity does work, at least in this application. What's strange however is that a shiny aluminum roof gets very hot in direct sun. I still think that surface smoothness is very relevant to reflectivity - presumably an aluminum roof is still a microscopically rough surface even if it appears shiny, while the aluminized Mylar is smoother (even though it's probably also wrinkled and uneven).

I think that there's a lot more complexity to this subject than most of us realize!

John

Smooth surfaces create hot spots. Mylar < flat white.

[1olfart]

My two bits....
I know that HyTech does sell just the beads, as well as the paint. They can be added to any paint. I've thought about adding them to a white tractor paint, for roof, and a tinted, for body. I should have asked, (but, NOOOO) if it was acceptable to add more than the minimum amt. of little buggers. My guess is that they would say no if spraying, but it might work if rolling. Probably better to do 2, or more, coats anyway.

[EastCoastCB]

Or add sawdust- Just as effective.