Insulating paint beads: Feedback from REAL people please

[Das Mel]

The sawdust is pretty rough since I didn't bother sifting to get only the real fine dust. There are a couple of chunks stuck in it. It actually looks a bit like stucco. If I would have eliminated the bigger chunks it probably wouldn't be all that bad. It's not really practical at any rate, though, since wood absorbs water.

Try sand?

 

[jazty]

The sawdust is pretty rough since I didn't bother sifting to get only the real fine dust. There are a couple of chunks stuck in it. It actually looks a bit like stucco. If I would have eliminated the bigger chunks it probably wouldn't be all that bad. It's not really practical at any rate, though, since wood absorbs water.

Try sand?

Thought about it, but there was no source of decent, dry sand around the garage. Had plenty of sawdust, though!

 

[Soundman1]

Results?

 

[jazty]

The weather hasn't been working with me. The results will come when the sun is shining..

 

[Lord-Maniac]

love the info on this site.....we the people by the people for the people !!! thanks for your test

 

[jazty]

It's no scorcher of a day, but the sun is shining brightly! That's all we need. I measured temperatures twice. Once at 2:10pm EST and again at 3:12pm EST.
I'll post the results textually at the bottom of the post for those who don't care to try to read the fuzzy thermometer display. Also, you can click on the image to go to Flickr, where you can view the image in it's original size.
Here's the data for the first batch:


Thermometer test.


Off-white paint: 41.2°C
21.4°C above ambient temperature


Black paint: 57.8°C
38°C above ambient temperature


4 coats of Solarflex roof paint: 33.7°C
13.9°C above ambient temperature


2 coats of Solarflex roof paint: 37.5°C
17.7°C above ambient temperature


2 coats of Solarflex roof paint + Hytech beads: 35.2°C
15.4°C above ambient temperature


2 coats of Solarflex roof paint + sawdust: 32.9°C
13.1°C above ambient temperature

I'll reiterate.
- Off-white paint: 41.2°C
- Black paint: 57.8°C
- 4 coats of Solarflex roof paint: 33.7°C
- 2 coats of Solarflex roof paint: 37.5°C
- 2 coats of Solarflex roof paint + Hytech beads: 35.2°C
- 2 coats of Solarflex roof paint + sawdust: 32.9°C

 

[jazty]

And now for the second batch @ 3:12pm EST


Temperature is the same, but the sun is in a different position.


Off-white paint: 40.9°C
21°C above ambient temperature


Black paint: 53.3°C
33.4°C above ambient temperature


4 coats Solarflex roof paint: 33.4°C
13.5°C above ambient temperature


2 coats Solarflex roof paint: 37.2°C
17.3°C above ambient temperature


2 coats Solarflex roof paint + Hytech beads: 34.2°C
14.3°C above ambient temperature


2 coats Solarflex roof paint + sawdust: 32.4°C
12.5°C above ambient temperature

To reiterate:
- Off-white paint: 40.9°C
- Black paint: 53.3°C
- 4 coats Solarflex roof paint: 33.4°C
- 2 coats Solarflex roof paint: 37.2°C
- 2 coats Solarflex roof paint + Hytech beads: 34.2°C
- 2 coats Solarflex roof paint + sawdust: 32.4°C

And the winner of both rounds! ...
...
...
SAWDUST AND ROOF PAINT!!!

I'm not all that surprised. It looks like it's all about being thick, white and reflective. Obviously, adding crap to the paint makes it a thicker product, whether it be Hytech NASA beads, sawdust, pixie dust, gravel, shredded tires, etc... A thicker product is more insulation. Now, for my uses, I'm just going to make a thick insulator of more paint layers. It looks nicer and - in the end - is cheaper. The Hytech Bus Kote is $197.50 + shipping for a 5 US gallon pail. Most white, elastomeric roof coatings I've seen (including Henry's Solarflex) hover around $80. I bought the Solarflex for $74 at Ace Hardware. To use twice as much paint on the roof is only $148. I'm going that route.

 

[ol trunt]

Jazty,we'll have to get you admitted to the "Myth Busters Hall Of Fame"! I expect that the rougher surface of the saw dust laden paint added to it's ability to shed heat due to it's greater exposed surface area--I guess that idea could be tested easily enough by using the same test panel in and out of the breeze. Thanks for going to all the bother. It was fun to see the results. Jack

 

[jazty]

I expect that the rougher surface of the saw dust laden paint added to it's ability to shed heat due to it's greater exposed surface area

That could very well be the case! I would guess that whatever the cause may be, the Hytech beads and sawdust share that characteristic. They both add more texture, thus more surface area, and they both thicken the paint.

 

[lornaschinske]

I'm surprised. I thought the much hyped beads would have been much more insulating. Now I'm glad that I just went cheap and stuck with the SolarFlex.

 

[big_bertha]

That's so surprising and SO helpful. Thank you.

 

[claydbal]

thank you jatsy for taking the time to experiment. its folks like you prove there are still great people left in the world. most are too busy, too big a hurry or wouldnt give someone else the time of day. thanks again for sharing time and expense so we can save same!

 

[IronChariot]

Jazty, hats-off to you for the thorough experiment. I am a little surprised at the sawdust result. Leads me to believe that just about any material that creates additional surface area would help. Looks like there is an opportunity here to find something cheaper than the beads that works better, more like the sawdust. The counter is additional cost, weight, potential degradation of paint life/performance, and possibly increased drag over-the-road. Maybe a business opportunity....

 

[jazty]

Thanks for the kind words everyone!

It's a bit warmer today. 24.5°C

- Off-white paint: 43.3°C
- Black paint: 57.1°C
- 4 coats Solarflex roof paint: 34.7°C
- 2 coats Solarflex roof paint: 36.9°C
- 2 coats Solarflex roof paint + Hytech beads: 35.5°C
- 2 coats Solarflex roof paint + sawdust: 32.4°C

Sawdust is still kickin' ass

 

[IronChariot]

Jazty, one question: I noticed that the sawdust panel appears to be the closet to the ground in one of the photos (the one where your assembly is vertical). Are your panels all horizontal while you are measuring? Thanks!

 

[jazty]

Yes. The rig is place across two saw-horses. I'll post a picture in a bit.

 

[jazty]

 

[IronChariot]

Awesome, thanks for clarifying. I presume the test rig is in 100% sun when you are testing? Looks like you have some spotty shadows over the rig in your latest pics. Just trying to think of anything at all that might impact you results. Are your sample pieces physically touching each other? That would also be a no-no.

 

[lornaschinske]

Are your sample pieces physically touching each other?

If you look closely at the last pic of the test pieces, you will there is a gap between the pieces. All in all, I think this was a very enlightening test. For starters, there was really very little difference between the various reflective paints although a pretty good difference between reflective paints and a white roof. That said, I think that no one should expect to only use reflective paint alone to reduce heat. I still think that Super Insulating the Roof is the best way to go as you would not only get maximum insulation added but also creat much needed interior/exterior thermal breaks and then use the reflective paint on top of all that. I'm still not sure I can get David to go that route... yet. We only have three coats (one 5 gallon bucket) of Henry's SolarFlex on our bus and really need another 5 gallon bucket spread around. Yesterday we were checking it out and touched up a couple of places where it had been scratched thru to the metal. I'm guessing from one of the tree limbs that we are parked under. It did scrub back white in the places I needed to patch up (also recoated part of a seam as it had a crack in it... not leaking, the coating had a 6" long hair line crack and I was up on the ladder anyway with the bucket of goo). Boy, the roof is filthy! All the birds roost in the trees and poop all over the bus, then add in the debris and dirt from the trees and the dust from the dust storms and it's a filthy mess. I wonder if we should run it thru a car wash at some point. But it's not going to reflect the heat back if it's so filthy. Hey! A NEW TEST!!!!! Now you can do a dirty roof test VS clean roof.

 

[jazty]

Awesome, thanks for clarifying. I presume the test rig is in 100% sun when you are testing? Looks like you have some spotty shadows over the rig in your latest pics. .

Yes, of course. Testing was done between 2-4. The picture I posted of the test rig was taken in the evening, hence the shadows.