Using Kool Seal on the Inside of the Outside?

[FC7039]

Originally Posted by aluminitus

If I use it, won't it actually make the trailer hotter than having no insulation at all? A million thanks to FC7039 for performing the test, even though the conclusions made me grumpy

I think if you use it against the aluminum, yes it will make things warmer. I will do more test with combinations.

If it works as a thermal break for the ribs, and if you cannot send your 5 galllons back, I would be willing to buy a gallon or so from you.

[robwok]

I think there are some other ways to think of this. Snow acts as an insulator once the outside temp reaches freezing. From 32 and up, it will cool things down. Once you reach 32, the snow isn't going to get any colder - think igloos. On the hot side, they make a silicone glove that you can use to put your hand in and grab really hot things. Or, think of a potholder that allows you to carry really hot items. It just doesn't conduct heat that well. The aluminum has very little mass in which to hold heat. When it's in the sun, it just allows that sun to heat up the surface and pass it right through. You need to break up that pass through. I believe what is happening with the white ceramic is that it adds a thermal mass to a metal that didn't have it before, but at some point it acts like the silicone oven mitt. If you're in Texas, and you have a blazing hot sun, it limits the uppper portion - maybe it stops the aluminum from transmitting anything hotter than 110 - so in those cases it prevents you from roasting inside, or allows your air conditioner to actually keep up. However, in more moderate situations, and it's sunny, then the sun goes behind a cloud, the white ceramic will continue to radiate heat inside where normally the outer skin would cool quickly.

Since we can artificially cool or heat the inside, the best option is something that insulates between the inner and outer skins, as well as limiting the radiant transmission of heat. The prodex and other products do have a mylar film to bounce back the radiant heat, but they also contain tons of air filled bubble that provide an air barrier should the mylar reflectiveness fail. The mylar can be used in multiple ways. I thin those in a cold climate would want the shiny side refleted to the inside of the trailer, and those in hot climates point it to the outside. Foam as well could be oriented. In hot climates, the foam is to the inside of the trailer, and in cold climates, to the inside. Best option seems to be the one already listed. Foam with shiny on both sides. If you can squeeze in the prodex with an air space you're good, but if they're touching, you're probably not getting much benefit. (I remember talking with the prodex people a long time ago about my garage door - they indicated backing the prodex with a foam sheet wasn't helpful, and could actually cause more transmission of heat if they touched. - I'm sure if you look up some of the specs on garage door isulation - which this stuff was originally intended for, there might be some helpful studies done in very scientifically controlled conditions.

[FC7039]

" I believe what is happening with the white ceramic is that it adds a thermal mass to a metal that didn't have it before,"

I do not think that it is additional mass (I could be wrong) but radiant heat. I can test this by doubling up the outside skin to be two sheets thick. I think more mass give can off more total heat but in my test the heat source is always present. Once the heat source is removed, the mass will have impact.

No direct conduction exists (i am discounting the skin conducts to air that convects to more air that conducts to the skin). I attribute the increased heat to radiant heat.

Some good reading on the subject
Physics of Foil: Radiant Barrier Stops Heat Gain & Loss in Buildings
SolarRadiationControl.htm

[aluminitus]

FC7039 - Your findings make sense, now that I have read HSC's description. "The seven ceramic compounds used create a barrier to catch and hold heat on the surface of the unit—be it pipe, furnace surface, boiler, etc. Unlike wraps that use air as the insulation component, the ceramic compounds in HSC™ Coating resist absorbing heat trying to come off the surface to escape." Maybe I should have read that in the first place! So HSC would be ideal for a cold weather environment, rather than for trying to keep the temperature down inside the trailer.

[aluminitus]

p.s. if anybody is interested in buying 5 gallons of HSC for a discounted rate ($210 plus shipping), let me know in the next few days!

[FC7039]

Originally Posted by aluminitus

FC7039 - Your findings make sense, now that I have read HSC's description. "The seven ceramic compounds used create a barrier to catch and hold heat on the surface of the unit—be it pipe, furnace surface, boiler, etc. Unlike wraps that use air as the insulation component, the ceramic compounds in HSC™ Coating resist absorbing heat trying to come off the surface to escape." Maybe I should have read that in the first place! So HSC would be ideal for a cold weather environment, rather than for trying to keep the temperature down inside the trailer.

I think it would work where you need some insulation but cannot use anything thick. I know they use this and like products (Lizard Skin) on hotrods to insulate metal. This is not aluminum.

I still think the conduction of heat via the ribs is the single greatest source of heat transfer. I will be testing this next. I am hoping HSC will help here as a thermal break. Others I have read have used felt and cork. I was also thinking of a strip of asbestos fire material. I have to source this from somewhere for teting.

I will test HSC's impact when it is combined with other forms of insulation. You never know.

[FC7039]

I ran a test where I added the bubble foil to the box with the HSC. I did not run it side by side with the control. I just wanted to see if there was any improvment if the HSC was used witgh the foil radiant barrier. After about one hour the temp was 96 which is close what the bubble foil was without the HSC. I did not run the test for two hours.

[slowmover]

Originally Posted by aluminitus

I'm not sure if this is in the right category, but here goes.

After reading Darkspeed's account of painting the interior of his Airstream's outer skin with ceramic insulation, I had a case of the green-eyed gazunga and wanted to do the same on mine. Then I found a thread about painting the roof with Kool-seal to make the roof bearable to sit on. It occurred to me that maybe I could paint the inside of the outside skin (clear as mud, right?) with Kool-seal and it would have the same effect, namely causing the skin to stay cool and better insulate the Airstream. Has anybody tried this? Do you suppose it would work?

I've had an interest in this for a while as well. But, as to the brand-specific Kool Seal the '76 SS I have at present has a layer or two on the roof . . and it runs off with every rain. Makes the stained anodized skin look even worse. I'd be careful about what heat or ozone or pollution do with any of these. I don't know how long this stuff has been on here (could be over 20-years), but I'm not so sure I'd want to have to keep re-doing it every 3-5 years (or?).

Interior spaces may have similar problems. As Darkspeed is an evil genius it may be that he knows something more we do not.

He must have gone snipe hunting with 2Air . . . .

.

[Wabbiteer]

Anyone want to cyclo-polish both sides of their outer shell skins in the name of science?

I wonder what the outside skin temperatures register at the time the internal readings are taken?

My take is, that clean aluminum does not radiat heat very well. It does conduct heat just fine. Painted, it radiates much better than if bare.

Aluminum can not radiate but a tiny portion of infrared wavelengths that another material would from the physics of aluminums molecular structure & spacing. Any coating (even left-over factory glue) mildew or even surface oxidation will defeat that and allow the IR to beam straight through.

I bought an aluminum-flake, ceramic hollow-sphere insulating paint as the final outside shells 'interior' paint - to top whatever goes on inbetween the outer skin and shell air space - probably on the roofs curve alone, and that is likely to aide heating season more than cooling season.

[FC7039]

Originally Posted by Wabbiteer

Anyone want to cyclo-polish both sides of their outer shell skins in the name of science?

I wonder what the outside skin temperatures register at the time the internal readings are taken?



Aluminum can not radiate but a tiny portion of infrared wavelengths that another material would from the physics of aluminums molecular structure & spacing. Any coating (even left-over factory glue) mildew or even surface oxidation will defeat that and allow the IR to beam straight through.

I bought an aluminum-flake, ceramic hollow-sphere insulating paint as the final outside shells 'interior' paint - to top whatever goes on inbetween the outer skin and shell air space - probably on the roofs curve alone, and that is likely to aide heating season more than cooling season.

If you want to send a small sample along, I will incorerate it into my test.

As you state, aluminum conducts just fine, so to me, the ribs are a major source of heat transfer. I have yet to find a suitable barrier.

[Wabbiteer]

This aluminum-leaf style paint has no mineral spirits or flammable solvents so it can ship priority mail - acrylic polymer with 45% metal and ceramic solids. Needs the metal to be oil-free, they don't call for primers, etc.

Send me an address via private messages, I'm 3 miles from the airport post office. I will try not to send you this head cold I'm fighting

~~~

I've been musing this going onto three years now - this spring I will need to make a choice... a rib-liner gasket review:

The biggest hitch with a gasket between ribs and liner is 'Gap Fastening' losing the metal-to-metal clamp, or decreasing the stretch tension of the pop-rivet anchoring liner firmly against the rib.

Softer materials will also show hole-filling tendencies, material creeps to the drilled hole if it isn't an interference fit already. Liner dimples around EVERY rivet where the gasket compressed would be unsightly and invite motion when the gasket further compresses over time.

On their own, aluminum pop rivets can/will loosen and lose their grip clamping force from vibration, SO INJECTING ANY silly extra play will start shearing whichever rivet happens to bind first and make the dreaded black-ring we see with out-of-balance running gear happen much easier.
~~~~

Anyhow...

I bought a length of .062" silicone sheet with a composition like solid forklift tires to use as the rib gasket - and thought I could get away with doubling up the rivets or somesuch but I don't see it happening - the silicone is too slick, no glues will bind to it so I can't tack it to the ribs. I did use it between the floor plywood & steel frame (punched holes in it so it would get anchored by adhesive) and floor has no squeaks and is hushed when walking on it.

Maybe just red rosin paper, the flexible roofing felt, welded to the ribs with a spray adhesive then coat it with the HSC?

[silverwoman]

I thought I ask here since it's easier & might help others. I saw a thread talking about insulating paint. I'm not sure this is the right thread or section of the forum but you're talking about Airstreams and I have an all steel trailer. I was thinking about insulation and what I can do to make my trailer well insulated. I thought about painting the inside with ceramic insulating paint, then adding insulation. I don't know the right terms but when the wood is redone & the windows are removed & it's down to bare metal & the sub floor is down, just shoot the whole inside with this ceramic paint. I saw the video I posted and they used it on the outside of the building. Do you think it would work on the inside? If I used it on the outside under the paint color, how do you think that would work? I think the inside would be best. I can call the company & ask if no one knows & I'll ask the dealer before I do it. If it works you could also use it on the inside of an Airstream if you're doing a complete renovation I think.

Ceramic Insulation Paint: Denver Test Project:

http://www.youtube.com/watch?v=yYfDp...eature=related

clear insulating coating:
https://www.inventables.com/technolo...lating-coating

[aluminitus]

Silverwoman,

I have 5 gallons of HSC (hot surface coating, a ceramic insulation paint) that I may be willing to part with at a discount, since it won't work on the polished bare aluminum of my airstream.

[silverwoman]

Originally Posted by aluminitus

Silverwoman,

I have 5 gallons of HSC (hot surface coating, a ceramic insulation paint) that I may be willing to part with at a discount, since it won't work on the polished bare aluminum of my airstream.

Thank you, I"m not sure about it yet. My son said using it on the interior won't work and I need to find out if it can be used under body paint and if it is effective that way. It would be a great way to insulate the trailer better. In the video it's painted on the outside. I think I'm going with Sherwin Williams industrial enamel I can get in a custom color and a top coat. It's less expensive and it looks good and my son said repainting every several years is easy to do. So it's not an expensive paint job. I need to call SW back and ask them. And I'll call the ceramic paint company too.

Right now, I'm looking for a place or space to start working on it so I'm not going to be ready for a while but I'm so anxious to get started.

[reinergirl]

Originally Posted by FC7039

If you want to send a small sample along, I will incorerate it into my test.

As you state, aluminum conducts just fine, so to me, the ribs are a major source of heat transfer. I have yet to find a suitable barrier.

Any further updates to this?????


Is this the paint? Attic Radiant Barrier Paint, Wall Vapor Retarder Coating Looks interesting....

[Wabbiteer]

Argh! I have two gallons of that; took one to store & had it shaken (3X to get the aluminum into suspension) then went looking for a sample sized container to send to another forum member to test it...

I plead cold & flu plus first warm weather as my distraction to cause such dereliction of Duty. Oops.

Got scaffolding up and am patching roof, when the vulkem is out I'll be slathering roof rivets and interior seams - then will break out the paint...

I have a non-contact thermometer to test interior surfaces in sunshine - bare aged aluminum, polished aluminum, one & two layers of Attic Radiant Barrier Paint...

Again - apologies.

[reinergirl]

No apologies necessary We all know that anything related to Airstreams takes at least three times as long to complete as you think it will!

[reinergirl]

Okay, any updates on this thread? Anyone done further testing? Or discover the perfect thermal break for the ribs?

[aluminitus]

I am hopefully going to be painting the HSC on the interior skins in a couple of weeks. I will let you know how it turns out!

[perryg114]

Painting the outside of the skin white will help ALOT. Painting the inside won't do much and it might even hurt. White paint and aluminum reflect about the same amount of light but white paint radiates absorbed heat much better than bare aluminum. The problem with white roof paint is keeping it white. Bare aluminum on the inside would be a good thing because aluminum does not radiate heat well. A radiation barrier and insulation will give you the best insulation. Painting the inside surface is going to help prevent leaks but thermally it does not make much sense. White cool seal is good, any other color won’t be so good. They have aluminized cool seal as well and it is not good. You want a low absorptivity to emissivity ratio. White paint is something like .3 and Aluminum is 3.

http://www.solarmirror.com/fom/fom-serve/cache/43.html

NASA uses this same concept to control the temperature of spacecraft in orbit. I use to test various coatings and materials for changes in the absorptivity to emissivity ratio or alpha over e. White is what is used on the sun facing side and black on the dark side. The problem is that stuff collects on the white paint surfaces and raises the alpha over e ratio. So a white paint that turns brown over time could be a real problem in space.

Perry