aziansenzation
New Member
Posts:15
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10 Aug 2007 12:12 AM |
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Has anyone tried and tested this type of liquid ceramic coating on SIPs? They claim that the coating has equivalency of R19 batt in just a couple of coats.
http://www.eaglecoatings.net/
I'm quite skeptical but intrigued at the same time... |
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cmkavala
Veteran Member
Posts:4324
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10 Aug 2007 07:29 AM |
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Azian
Ceramic coatings are great to reflect heat and UV rays , but the R-19 equivilacy ?
I wouldn't want to to count on a coating to keep a house warm in acalgary winter.
If it's too good to be true?
We are currently using an Astec ceramic coating over metal panel roof for the reflection and water proofing qualities but not for any R - value |
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Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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aziansenzation
New Member
Posts:15
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10 Aug 2007 08:06 AM |
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Good morning!
Apparently there is more than one manufacturer that "claims" this. Apparently the technology is true use for NASA. (not their coaiting but a specifically engineered coating designed by NASA). But how much it reflects, I'm not sure since testing for r-value on a "paint" is not achievable but a relative comparison. I will have to contact the local "demo" sites here to see what's up with that. But think of the savings for use on a 4in. SIP. Apparently "Insulative Paints" have been around for a long time... |
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slenzen
Basic Member
Posts:434
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10 Aug 2007 01:30 PM |
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Here is a discussion of ceramic coatings.
http://www.fabprefab.net/smf/index.php?topic=971.0 |
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aziansenzation
New Member
Posts:15
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10 Aug 2007 02:25 PM |
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It still sounds like a big sales pitch. ie the owner of the company is rebutting people's skepticism's about the product. Is there any hard proof? It's probably quite easy to test with a large highly conductive metal panel, coat the whole thing with "the paint" (on both sides), blast it with a torch over (x) minutes and measure the temperature on both torch side and opposite side. |
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aziansenzation
New Member
Posts:15
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10 Aug 2007 03:46 PM |
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Kidding aside.. what if it's true? There's other companies in the US producing similar products... |
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Dick Mills
Basic Member
Posts:217
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10 Aug 2007 05:05 PM |
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There are two main reasons why ceramic coatings work. The first is reflectivity. We usually feel colder when a breeze blows by, but most don't realize that the majority of heat loss (body heat or otherwise) is lost due to radiation. Unlike convective losses, radiation occurs pretty consistently over a large range of temperatures. So, reflecting that heat back into your home is highly beneficial.
The second reason is convection. These insulative coatings are basically latex paint with borosilicate ceramic beads. The beads are microspheres which encapsulate a void that is under a relatively high vacuum. The vacuum is a very effective mechanism for eliminating convection losses. The air moving around in the house is going to lose (or pickup) heat from the wall and ceiling surfaces, but much of that heat is going to begin radiating from the surface of the wall, and be reflected back into the room, and the vacuum in the microspheres eliminates acts as a convective barrier to heat loss.
So, the only method of heat loss that isn't covered well is conduction. And foam insulation is perhaps the best method of eliminating conduction.
My question, is why anyone is willing to pay $54/gallon for this stuff. Granted, there are patents on the process, and until the patents lapse, other manufacturers are barred from entering the market. But anyone (especially DIYers) can buy latex paint (for probably $18/gallon), and then depending on the quantity of borosilicate microspheres, you can buy them for between $7 and $4/pound (two pounds are roughly one gallon of beads). And then you can mix them yourself. I am sure that the actual ratio of ceramic beads to latex paint is a closely guarded trade secret, but just weighing a gallon of the stuff should provide a pretty good estimation of the ratio.
By my calculation, at $18/gallon of paint, and $14/gallon of beads with a 50/50 mix would yield a net price of $16/gallon of insulative paint.
So, again, why would anyone (particularly DIYers) pay $54/gallon for this stuff.
Oh, and by the way, there is a dome (geodesic) manufacturer that has a testimonial from a guy who has one of their fabric covered domes in the Colorado mountains. The interior of his dome is coated with this stuff, and he has a small wood stove. He claims that it stays quite warm inside even with a layer of snow on top of the dome. Others say that with relatively small heat sources that they stay warm in places like Minnesota (???? I get those M states mixed up a lot) all through the winter. One even claimed that when they ran out wood in the wood stove, that the temp only dropped to 50F with sub-zero temps outside.
Whether you believe the claims or not, stopping by a fiberglass supply shop to pick up a quart of borosilicate microspheres to add to a quart of latex paint seems like a relatively simple (and inexpensive) means of testing the theory.
Dick Mills |
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aziansenzation
New Member
Posts:15
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10 Aug 2007 10:33 PM |
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Ok.. lets assume that it works.. so then why hasn't the SIP in all their infinite engineering wisdom not use such a product and make a r-80 insulative 4in. wall (paint + urethane wall).. heck! Why would i use a sip in the first place if i can just use stuco on gyspum, paint the stuco and innner facing gypsm, no insulation between normal 2x4, and encclose the thing with another gypsum board? There's must be some logical explanation for this other than cost... or controlled secrecy..
As for the beads I'm assuming there has to be great quantities of it in the paint otherwise some areas would have no ceramic coating..ie then its performance compromised.. but what about specifically choosing certain type of reflective ceramics as to which wavelengths that it can reflect? Is this also true? |
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highperformance
New Member
Posts:14
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11 Aug 2007 12:37 AM |
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While we are talking about coatings, what about using GFRC (glass fiber reinforced concrete), instead of OSB??? I see companies starting to coat foam blocks with GFRC, and some with Portland Cement products. (solarcrete.com, m2ireland.com, strataca.com.... to name a few) Might not be as advanced as ceramic, but is certainly a viable (and more affordable) option..
Alot of the problems I read about with OSB SIP's are installation and customization of the panels. With these systems, you set the form with EPS blocks and spray-coat it with a cement product, or ceramic for that matter? Seems like customization and on-site modifications would be quite easy, and make the installation that much easier. What are holding these products back from being mainstream? |
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Dick Mills
Basic Member
Posts:217
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11 Aug 2007 01:35 AM |
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Highperformance,
I thought that concrete was too alkaline for glass fibers which is why polypropylene fibers were used instead?
Dick Mills |
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highperformance
New Member
Posts:14
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11 Aug 2007 10:36 AM |
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Dick,
The fibers they are using now are alkali-resistant. This was developed several years back, I believe.
From what I have read, the GFRC is less of an insulative coating, and more of a thin, lightweight structural component. Strataca.com claims that EPS combined with GFRC can achieve R40 in the walls and R100 in the roof. Not sure how they measured that.... |
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aziansenzation
New Member
Posts:15
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11 Aug 2007 11:50 AM |
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comeon.. you really want a 16 inch wall? where internal space is a premium? i'm talking about a SIP which can achieve the same R-Value in 4 inches if this coating is feasible..then think about a 2 in. wall (probably not, because of structural and noise permeable properties).. |
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highperformance
New Member
Posts:14
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11 Aug 2007 12:45 PM |
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I think I remember seeing that the wall depth is optional from 6 to 12 inches, but not sure. My point being that with an eye towards cost and ease of use/availablity, GFRC and EPS seem like a reasonable alternative. Forgive my ignorance, but does Liquid Ceramic provide for structural integrity? |
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aziansenzation
New Member
Posts:15
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11 Aug 2007 01:06 PM |
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most of the heat loss through convection is prevented from some sort of captured air (air being an excellent insulator when no convection occurs such as an eps or urethane core)..liquid ceramic coatings are not structural.. it's just a special paint which uses reflection instead of absorbance to control heat..
my point is: if there is substantial evidence that it actually works (independent testing, etc.) and if there are SIP manufacturers using them?
i was looking at the Astec coating Chris mentioned earlier and apparently it does have a relatively high UV and IR reflectance.. but why not a high r-value from that roof he mentioned? my best guess is because of the high thermal conductance of steel.. |
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Dick Mills
Basic Member
Posts:217
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11 Aug 2007 02:56 PM |
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Highperformance,
I did some research, and they are using zirconia at about 17% ratio with silica to make AR glass fibers. It sounds like their biggest problem is that zirconia is about $30/kg, and that could considerably increase the cost of the glass fiber. But at a 5% admix they claim to get 6000 psi concrete - and that is impressive. Does concrete adhere directly to EPS? Or do they form it into panels and glue it? With PU, the polyurethane will glue itself to just about anything, so adhesive wouldn't be necessary there, but the GFRC would need to be formed into panels first.
Dick |
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highperformance
New Member
Posts:14
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11 Aug 2007 07:15 PM |
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Dick,
From the media posted on Strataca.com, they spray it on, just like shotcrete. They basically just stack and spray the blocks with approx 1/4" GFRC. The only mention of adhesion is between the blocks when they are being set.
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aziansenzation
New Member
Posts:8
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14 Aug 2007 09:17 PM |
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OK! I found a legitimate company that does both paintable ceramic coatings and ceramic style substrate hardboards for REFRACTORY use. Meaning they're used for ovens, kilns, etc. So the concept of paintable ceramic coatings for insulative use is very intrigueing.
Update:
Here was an indepedent test done on roofs with regular white paint and borosilicate spheres (ceramic). It looks like there's no significant difference in direct sunlight between regular white paint and the special ceramic coating. Although the ceramic did perform better, cost wise it's might not be worth it to most people..substrate type and surface quality also are accounted..take a look..
http://www.roofingtechnology.net/articles.php/ceramic-coatings
So... ceramic coatings do work.. but it sunny areas , like Arizona for example, it's just as effective to use a regular white paint.. the smoother and glossier the better.
Here's a list of albedo type surfaces if you want to control heat:
http://www.bchydro.com/business/investigate/investigate6018.html |
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donner
New Member
Posts:2
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15 Aug 2007 08:30 PM |
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Posted By Dick Mills on 08/10/2007 5:05 PM
...
The second reason is convection. These insulative coatings are basically latex paint with borosilicate ceramic beads. The beads are microspheres which encapsulate a void that is under a relatively high vacuum. The vacuum is a very effective mechanism for eliminating convection losses. The air moving around in the house is going to lose (or pickup) heat from the wall and ceiling surfaces, but much of that heat is going to begin radiating from the surface of the wall, and be reflected back into the room, and the vacuum in the microspheres eliminates acts as a convective barrier to heat loss.
So, the only method of heat loss that isn't covered well is conduction. And foam insulation is perhaps the best method of eliminating conduction.
...
Dick Mills Small correction on the physics here. The second reason is also conduction in terms of insulating a home. Convection is prevented by not letting the warm air in the home move to the outside and the cool air outside move inside, or vice versa when cooling. Conduction is the transfer of heat when molecules of one material bump into molecules of another material. So, a vaccuum is the ideal conductive insulator, so the beads reduce conduction not convection as the wall itself prevents convection already. Air is also an excellent conductive insulator, as long as you don't let it move because then convection kills you. Pretty much every home insulating material out there is based on the fact that if you do not let air move it is a good insulator. EPS, fiberglass, etc... Or, aerogels which are some of the best insulators out there due to being mostly immobile air. You may then ask why not have an empty air space in the wall cavity. The reason is then you have good insulation between the innerwall and the airspace and the outer wall and the air space. But, crap in the airspace as the air can freely move from one wall to another. The material of the insulation forces air based conduction to be the primary means of heat transfer between the inner and outer wall.
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Dick Mills
Basic Member
Posts:217
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15 Aug 2007 10:33 PM |
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Hi Donner,
I don't mean to be a stickler, but that air-to-air conduction is the result of convection. When you have a surface which is warmer than the air that comes in contact with that surface, then it creates convection currents. Those convection currents ensure that the heat is conducted through the cavity. The lack of any air in the space (due to the vacuum) eliminates that convection, but the conduction of heat through the material (in this case the ceramic microshperes) can still occur.
Dick Mills |
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donner
New Member
Posts:2
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16 Aug 2007 12:13 PM |
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Hi Dick-
We are both right. I was thinking relative to paint with no spheres. There is obviously no convection going on in dry paint that is essentially a solid. So, adding spheres (air filled or not) does nothing to reduce convection in paint.
You were thinking spheres with air vs spheres without air. For which internal to the sphere there would be convection if it had air in it.
Don W
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