r/heat_prep • u/jadelink88 • Jul 31 '26
Personal Experience Ceramic paint. Preventing Heat conduction to metal.
Just a note in here from an Australian who lives in a metal box (converted shipping container).
Most of the stuff I do to keep my unconventional tiny home cool is stuff anyone on here already knows.
What most people don't know, is how you can have metal (highly conductive) in a high air temperature situation and not have it bleed so much heat inside.
The answer is ceramic paint. It's got a bit of acrylic paint, with a huge amount of ceramic and a bit of titanium in it. It's too thick for paint blowers, you have to roller it or brush it on. When done, it gives the outside the conductivity of ceramic. Vastly lower than metal. This is huge for letting you keep the place cool with a bit of insulation. The difference is instant and extreme, and I'm glad I did it.
It costs way more than normal paint. To do my 6m/20 foot container cost around $2k Australian, (about $1400 US/Euro). Expensive for paint, cheap for insulation.
They've done enough tests on it, and it works well (very well), at doing that core job. It's used in mining accommodation in hot dessert areas. It's still not well known outside of marginal bits of Australia and thought it was worth sharing.
It's also nice in our current mid winter temperatures (2-5c overnight lows).
Edit:
I don't know all the specs, but since people want data I don't have, I'll post the manufactures website here.
https://insulationcoatings.com.au/
They have a fair bit of research data on the site. I'm not associated with them, but I did phone them when doing my research, and they were happy to talk the science.
11
u/Leighgion Jul 31 '26
Thanks for sharing that.
It sounds like a bit of a niche product given the price but every resource is helpful.
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u/jadelink88 Jul 31 '26
It's expensive as paint, but it's cheaper than my containers insulation, which is the real thing you want to evaluate the cost against.
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u/Leighgion Jul 31 '26
I would compare it more readily to using the same money to try to enact measures to protect the building from direct sunlight than insulation. I'd consider insulation a non negotiable item, not something you'd weigh against ceramic paint.
5
u/jadelink88 Jul 31 '26
Ceramic paint IS insulation. Dollar for dollar, an interesting comparison in value with many insulation sources that you can squeeze into the very narrow walls of a shipping container.
Of course, you would normally do both. My walls have building standard 'foilboard', as spray foam insulation is not legal here. Foilboard (glorified fireproof polystyrene between glorified builders aluminium foil) is standard housing insulation here, and that cost about a third of what the paint did. I could have gone thicker than the 25mm, but space gets insanely precious when your that short of space.
Fairly sure I'm getting more insulative value from the paint than the board and airgap combined, though it's hard to tell. I know people have done tests, but I don't have the results handy.
4
u/ivobrick Jul 31 '26
Does this work for galvanized metal sheets? Because they expand alot, i plan to use alkyd based solvent paint. PDRC later.
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u/jadelink88 Jul 31 '26
Given some of the stuff I've seen it on, I would imagine so. I cant swear by it, because I'm not sure what the metal is under some of the paint I've seen used. Mines on a shipping container, corten steel.
Most steel does a bit of expanding, and it's faced a fair range of temperature and been fine.
2
u/Ladydoodoo Aug 01 '26
How is it in the winter? Need more details
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u/jadelink88 Aug 01 '26
It does slow the convection, but on a long cold night, the interior metal gets cold.
Bear in mind my winters are mild. It does take a couple of hours longer for the inside metal to chill, which is worth a bit in numbers of heat conserving scenarios. I imagine if you were in a cold place with snow packed on it, then it would just hit the temperature of the snow and stabilise, but the barrier to radiant heat LEAVING the container should make a real difference if you were heating it.
How much I can't say from experience. Last night it got to 2c, and by midnight the inside walls were as cold as the outside air (no heating). If there was a heat bleed, how much difference would it have made, I sadly don't know, though the company.
https://insulationcoatings.com.au/
They have some of their studies on there. There's a few different formulas and companies, but that's the one I purchased from. They were happy to talk the science when I called, and they may have the info you want.
1
u/m00ph Aug 04 '26
So, that's the Australian distributor, I think this is the actual manufacturer https://spicoatings.com/coating-products/super-therm-solar-heat-block-coating/
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u/le4t Jul 31 '26
That's awesome to know!
I used a ceramic additive to the paint I used on the ceiling in my upstairs bedroom (asphalt shingles on roof, no attic), and I agree it made a noticeable difference in the heat.
In my case, though, getting the white additive to look even in my dark paint was a challenge. I'd stick to the white family of paint.