Insulate underneath body?

HAF

Active member
I have used Lizard Skin product. It really worked. See videos online showing how it works.
 

luthj

Engineer In Residence
None of these thin products and or snake oil count as real insulation for a camper conversion. If it doesn't list an ASTM tested R value, its not worth considering.
 

macexpress

Observer
I had closed cell foam sprayed under my enclosed trailer that I used for work. I've put around 70,000 miles on it since then in all kinds of weather and it hasn't soaked up any moisture. It would be really hard to do the underside of my van completely that way though, you wouldn't want to cover any wiring or fuel or brake lines, anything mechanical. When closed cell foam sets up it is rock hard.
 

HAF

Active member
None of these thin products and or snake oil count as real insulation for a camper conversion. If it doesn't list an ASTM tested R value, its not worth considering.
Ceramic micro spheres are processed with a vacuum inside the sphere. Temperature transfer is limited in a vacuum. The sphere shape of these micro balls produces limited conduction due to such a small surface area touching one another.
I have personally tested micro spheres for temp transfer and find they actually work. When mixed with epoxy and vacuum packed in a 1" thick foil bag, R50 and better have been achieved.
I have tried Lizard skin and tested on a .125" thick sheet of aluminum. One side painted black and the other bare. Coated half the bottom side with paint mixed with LS and the other side bare. Set this out in the sun light on a 70 degree day. The results were dramatic. The un-coated side was to hot to touch. The coated side remained at near 70 degree temp.
I don't have a dog in the fight, however I have found micro spheres really work. While not a substitute for full insulation, coated surfaces can really augment and perhaps reduce the amount of insulation thickness required.
Of note-the underside of the space shuttles have a material similar to this designed to keep it from burning up.
 

pappawheely

Autonomous4X4
Ceramic micro spheres are processed with a vacuum inside the sphere. Temperature transfer is limited in a vacuum. The sphere shape of these micro balls produces limited conduction due to such a small surface area touching one another.
I have personally tested micro spheres for temp transfer and find they actually work. When mixed with epoxy and vacuum packed in a 1" thick foil bag, R50 and better have been achieved.
I have tried Lizard skin and tested on a .125" thick sheet of aluminum. One side painted black and the other bare. Coated half the bottom side with paint mixed with LS and the other side bare. Set this out in the sun light on a 70 degree day. The results were dramatic. The un-coated side was to hot to touch. The coated side remained at near 70 degree temp.
I don't have a dog in the fight, however I have found micro spheres really work. While not a substitute for full insulation, coated surfaces can really augment and perhaps reduce the amount of insulation thickness required.
Of note-the underside of the space shuttles have a material similar to this designed to keep it from burning up.
I have had the same results. I saw a huge difference in temperature after painting my roof with a micro-sphere paint. I was very skeptical before seeing the results with my own eyes. Also, I recently got a quote from a local spray foam supplier. They told me that they spray their own trucks including the underside of the body.
 

HAF

Active member
I have mixed an abundance of the micro spheres in floor paint for added insulation. Here it is shown in a camper I am building. There is 1/2" foam and 3" thick insulation beneath the painted floor surface. I live in Minnesota-gets sort of cold here which requires a more thoughtful approach to insulation. Will keep the camper cooler in summer.
I built an aluminum camper a couple of years ago-coated entire inside before of body before insulation. Loaded up camper for a trip out west-was 80 degrees here when I left. 12 hours later I pulled into truck stop in Nebraska to sleep. It was cold and spitting snow when I opened the door to the camper. It was still super warm inside despite no heater!
 

Attachments

ricardo

Observer
Ceramic micro spheres are processed with a vacuum inside the sphere. Temperature transfer is limited in a vacuum. The sphere shape of these micro balls produces limited conduction due to such a small surface area touching one another.
I have personally tested micro spheres for temp transfer and find they actually work. When mixed with epoxy and vacuum packed in a 1" thick foil bag, R50 and better have been achieved.
I have tried Lizard skin and tested on a .125" thick sheet of aluminum. One side painted black and the other bare. Coated half the bottom side with paint mixed with LS and the other side bare. Set this out in the sun light on a 70 degree day. The results were dramatic. The un-coated side was to hot to touch. The coated side remained at near 70 degree temp.
I don't have a dog in the fight, however I have found micro spheres really work. While not a substitute for full insulation, coated surfaces can really augment and perhaps reduce the amount of insulation thickness required.
Of note-the underside of the space shuttles have a material similar to this designed to keep it from burning up.
Sciences Rules..

Great compendium, thank you..

I work for companies like Mountain hardware, trust me making 3 pound four season tents is not easy, materials are a big part of the equation but the real secret is the configuration of the "air pockets", shapes, venturi air exchange's. etc

Keep it up Haf..

So any specific brand, type Specification.. bonding agents..!?!?
 

HAF

Active member
I have used Thermacells (sold on Amazon) as well as Lizard Skin and 3M micro spheres. Lizard skin was an all in one material. All of them actually worked. I found coating the outside (like a roof) to be more effective. It seems to stop a lot of heat transfer before insulation. Given these materials consist of ceramic hollow spheres, they are light weight and tough. Pour enough of it on a camper and it will float like a boat!
 

ricardo

Observer
I have used Thermacells (sold on Amazon) as well as Lizard Skin and 3M micro spheres. Lizard skin was an all in one material. All of them actually worked. I found coating the outside (like a roof) to be more effective. It seems to stop a lot of heat transfer before insulation. Given these materials consist of ceramic hollow spheres, they are light weight and tough. Pour enough of it on a camper and it will float like a boat!
I build composite canard airplanes for years and we use "Micro balloons" but as fillers, smaller than sand particles, delighted to touch, impossible to clean if you spill them..


but I do understand the Hollowness" can make a massive difference

Taking about Textures and colors, Mate Black roofs may look very manly but man are they hot, High luster silver or at least white is a passive way to keep the vehicle a little colder..

important to remember that Heat can be as bad a "Cold"
 

Speedwagon

New member
I’ve used Grace ice and water shield (a roofing product) in place of dynamat for years on car rebuild projects. In Minneapolis any lumberyard would have it, about 1/4 or less of the dynamat cost and just as effective.
That's what they used on my roof when I had it done in August.
 

Speedwagon

New member
I have used Thermacells (sold on Amazon) as well as Lizard Skin and 3M micro spheres. Lizard skin was an all in one material. All of them actually worked. I found coating the outside (like a roof) to be more effective. It seems to stop a lot of heat transfer before insulation. Given these materials consist of ceramic hollow spheres, they are light weight and tough. Pour enough of it on a camper and it will float like a boat!
I had never heard of such products before. I was just reading more about the Lizardskin. Quite fascinating, and they say you can use it under the vehicle as well!

And if it can make a HMMWV quiter, well... that's saying a lot. Those things are loud AF!
Lizardskin on a HMMWV review
 
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luthj

Engineer In Residence
Sure those products provide a small amount of insulation, so does a couple pieces of newspaper. The point is that this is all subjective without an actual R-value test. R-value testing is not expensive and every reputable company does it. the fact that they don't list one, instead using generic and pseudoscience terms, means that the actual insulation value is minimal. Yes it may be noticeable compared to un-insulated but comparing actual insulation to a thin layer of micro spheres is a laughable comparison.

Companies I've worked with have evaluated similar products for installation on aircraft where weight and R-value for thickness is up to tantamount importance. We found these products to provide almost no R-value compared to typical insulation products in the 0.5"+ inch thickness range. Especially when dealing with both hot and cold temperature gradients.

Then there's the combination of cost and time. Lizard skin in similar products lose dramatically on all of these fronts compared to typical insulation products used in automobiles and campers.

If you are really concerned about the ultimate R-value. You can easily achieve R25 or higher per inch by using vacuum insulated panels. They have obvious limitations in their usage and installation but provide a far superior value to any other insulation product available on the market.

I call BS on R50 per inch. Provide an independently verified test with the average value of a one square-foot panel being in this range please. Just not realistic.

This is one area where anecdotes simply don't cut it. The testing is simple and inexpensive for a mfg to perform. it is not done because it provides a effective baseline comparison. Which would make their products look very poor.
 

Alloy

Well-known member
I had closed cell foam sprayed under my enclosed trailer that I used for work. I've put around 70,000 miles on it since then in all kinds of weather and it hasn't soaked up any moisture. It would be really hard to do the underside of my van completely that way though, you wouldn't want to cover any wiring or fuel or brake lines, anything mechanical. When closed cell foam sets up it is rock hard.
Have you pressed your thumb into the foam in a few spots and checked any damaged areas for water.
 

HAF

Active member
Sure those products provide a small amount of insulation, so does a couple pieces of newspaper. The point is that this is all subjective without an actual R-value test. R-value testing is not expensive and every reputable company does it. the fact that they don't list one, instead using generic and pseudoscience terms, means that the actual insulation value is minimal. Yes it may be noticeable compared to un-insulated but comparing actual insulation to a thin layer of micro spheres is a laughable comparison.

Companies I've worked with have evaluated similar products for installation on aircraft where weight and R-value for thickness is up to tantamount importance. We found these products to provide almost no R-value compared to typical insulation products in the 0.5"+ inch thickness range. Especially when dealing with both hot and cold temperature gradients.

Then there's the combination of cost and time. Lizard skin in similar products lose dramatically on all of these fronts compared to typical insulation products used in automobiles and campers.

If you are really concerned about the ultimate R-value. You can easily achieve R25 or higher per inch by using vacuum insulated panels. They have obvious limitations in their usage and installation but provide a far superior value to any other insulation product available on the market.

I call BS on R50 per inch. Provide an independently verified test with the average value of a one square-foot panel being in this range please. Just not realistic.

This is one area where anecdotes simply don't cut it. The testing is simple and inexpensive for a mfg to perform. it is not done because it provides a effective baseline comparison. Which would make their products look very poor.
Might want to tell those companies that they can achieve R50 in thicknesses better than Home Depot fiberglass. Per ASTM C518-93, micro bubbles in 1" thick panels have a thermal conductivity at .065 mbar (vacuum) at 75 degrees F of .020 BTU-in/per square foot-hr-E. Panels are commercially available and are being installed on roofs of commercial and industrial buildings. We are now seeing these panels replace typical SIP panels in industrial freezing tunnels and continuous ovens. These plants are reporting significant energy reductions. Micro bubbles along with fumed silica can be made into composites and can be found in most hi-tech/space applications.
Coatings can greatly reduce thermal conductivity.
 

1leglance

2007 Expedition Trophy Champion, Overland Certifie
Funny that we can spend so much time, money and mental effort on insulation......when not matter what you do a passive system will equalize with ambient sooner or later.
With my new van build I figure I will have active heating and cooling most of time and since I have a short wheelbase, low roof I am more concerned with maximizing my interior space vs thick insulation on the floor, walls and roof.

Sound dampening/deadening is more important but even with that I am trying not to go crazy.
All that said I do enjoy reading and learning as much as I can.
 

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