Closed cell spray foam insulation?

[putback]

Not sure foam is worth the risk in an Airstream. I have a '64 T28 avion. It is foam insulated. I removed 2 sections of interior skin and the foam was as new. However Avion has a rigid frame, little or no flex, and the morride suspension system. On the '62 ambassador I just striped down the p.o. had replaced the front 8 ft of floor. In doing so he'd removed the lower interior skins from the door around under the ft end cap and 6 ft down the street side. He replaced the fiberglass with spray foam insulation under said panels. The front foam under the endcap was moderately cracked and separated, but serviceable. The further towards the back it went the worse it was. Under the street side window the foam fell out in pieces, some the size of a deck of cards. I don't know what type of spray foam was used and the trailer was in need of a full restore. However in this case the foam failed. According to the p.o. the job was 5 yrs old.

[Ringoo7]

Thanks for the information. Is there any way to find out what foam was used by the po of the Airsrteam?

[SafariSS]

I am a home builder and we use foams extensively in high end construction now. The brand we use is isonene which is a urethane, part A and B. The thing I would be worried about is the little heat that is generated from the chemical reaction would wrinkle and warp wide sections of panels. I am on the sprinter van forum as well and several guys had their vans sprayed only to find wavy bodywork after the job.

Also when you have to find a leak it is crazy. Like a surfboard with a leak you never know how much water has soaked up, where it is coming from etc.

I like how dense it is however.

[alumascoupe]

More fuel for the fire...Best friend had a metal qounset hut garage foamed, the foam withstands extreme heat from his wood burner chimney pass through, works amazing as far as insulating, deadens sound, and on the highly used ( but now significantly heavier) garage door that has been hit/slammed and dented a lot.... only 2 small pieces have separated in 5 years. That door slamming is a harsher impact than an AS should ever see. One issue is the fact the foam either has to be sprayed in low or overfilled and trimmed to flush, which "opens" all the closed cells on the trimmed side.
Fiberglass is under scrutiny as a known and identified carcinogen, is detectable in minute amounts in air all over the planet, and could possibly damage your lungs just like asbestos fibers, we all know how itchy it is when all those fibers pierce our skin, imagine your much more delicate lung tissues vs those same glass fibers ? Pick your poison I guess, everything man made in the chemical age turns out to be toxic after the last generation identifies its dangers for us, lead phase out, high VOC paints, PVC off gassing the most recent, PEX users beware come 2030 ! hows that for some gas on the fire !

[wahoonc]

Originally Posted by Aviator

Current transport aircraft (airliners and business type) are insulated with blankets between the ribs. I am not sure what the material is, but it is not foam. The blankets allow the mechanics to easily move them out of the way when repairs are needed, then put them back.

It has been a couple of years since I last stopped over at the maintenance base, but that is what they use. I watched a show on the construction of the new B787 and it used the same blankets.

According to a couple of aircraft mechanics I know the primary reason for using the blankets are two fold. Weight and the need to be able to routinely inspect ALL connections of frames on a periodic basis, as well as ease of repairs.

Aaron

[Silverflames]

My 69 ambassador has the spray foam on the bottom of the floor and on the frame. Once it gets wet it stays wet. Holds moisture right up next to the frame. If it stays dry it's great.

Did a real number on the frame. Plus it's a real mess to work with, very flammable, and is really a pain in the butt. It was only used in 69.

[putback]

Originally Posted by Ringoo7

Thanks for the information. Is there any way to find out what foam was used by the po of the Airsrteam?

The ph # is no longer in service. I'll show a piece to a couple contractors I know and get their opinion. May take a day or two.

[putback]

Originally Posted by putback

The ph # is no longer in service. I'll show a piece to a couple contractors I know and get their opinion. May take a day or two.

Got lucky, stopped by the local building supply early this A M. Lot of guys. All agreed the sample was common rattle can low expansion foam. Then the Fiberglass vs HIGH quality foam debate began. They reached concenses. "You know fiberglass works. If foam doesn't you are truly screwed!" So there you have it, you still have no certain answer..

[InsideOut]

Is the idea of using spray foam a way of getting more insulating value without taking skins off? If so, I don't think it would be a great solution for a couple of reasons:

• What about the old insulation already there? Skins will have to be removed to get that out...
  
• Any kind of spray foam would be difficult to apply evenly w/o taking off the skins and trimming it.
  
• How would you know if if was applied everywhere to maximize the insulation effect? Again, skins would have to be removed to verify...
  
• Aluminum being so soft and flexible, in areas that too much expanding foam was sprayed in the gap (assuming the skins are both intact) it could dent/oil can the shell.
  
• If for some reason you have a repair to be made, like fishing an electrical wire - it's going to be more difficult.
  
• During a repair - several years down the road...what about the compatibility of old vs new foam products? Will one dissolve the other?
  
• If it doesn't work, you are going to have a big mess to clean up.
  

I don't know, but it seems that if it was "the perfect solution" Airstream would be using it. Sounds like they tried it & it didn't work - for whatever reason, and they haven't tried it again.

Shari

[Ringoo7]

Thanks,Putback, for taking the time to identify the foam. Yes, I'm looking for maximum R-value on a total redo. Skins would be removed. What is the max r-value and material or combination of materials others have used? I am not dead set on foam. I just thought foam would be one of the higher r-value materials.

[Silverflames]

There was one post talking about a reflective insulation that comes in rolls. It was thicker than the stuff you buy at lowes. I want to say it had r14 value, but im Nit sure.


Ok found the post it's Prodex total boasting a r value of r16. But it's pricey...

http://m.insulation4less.com/Product...x?ProductID=20

[wahoonc]

Originally Posted by InsideOut

Is the idea of using spray foam a way of getting more insulating value without taking skins off? If so, I don't think it would be a great solution for a couple of reasons:

• What about the old insulation already there? Skins will have to be removed to get that out...
  
• Any kind of spray foam would be difficult to apply evenly w/o taking off the skins and trimming it.
  
• How would you know if if was applied everywhere to maximize the insulation effect? Again, skins would have to be removed to verify...
  
• Aluminum being so soft and flexible, in areas that too much expanding foam was sprayed in the gap (assuming the skins are both intact) it could dent/oil can the shell.
  
• If for some reason you have a repair to be made, like fishing an electrical wire - it's going to be more difficult.
  
• During a repair - several years down the road...what about the compatibility of old vs new foam products? Will one dissolve the other?
  
• If it doesn't work, you are going to have a big mess to clean up.
  

I don't know, but it seems that if it was "the perfect solution" Airstream would be using it. Sounds like they tried it & it didn't work - for whatever reason, and they haven't tried it again.

Shari

Interesting list...

However in Airstream's case I suspect one of two reasons...

1. It would cut into profit margins
2. we have always done it this way

Must my take on the situation. I have seen a couple of bus conversions where a spray foam of some sort was used, one of those buses had close to a half million miles on it since the conversion was done and the owner was still happy with the insulation job.

To me the single biggest advantage would be using a spray foam that doesn't absorb water.

Aaron

[Ringoo7]

I have doubts on the r-value of prodex. There is a lot of discussion on their claims online. Has anyone tried the aero gel insulation derivatives?

[sjgharib]

I was thinking of using the basic "bubble foil" as an insulation versus fiberglass.
I was also contemplating using the hy-tech ceramic EPDM paint (they call it BUS-KOTE) on the INSIDE of the shell. It seemed like a good way to seal as well as add a radiant reflective barrier. Thoughts?

[putback]

Originally Posted by Ringoo7

Thanks,Putback, for taking the time to identify the foam. Yes, I'm looking for maximum R-value on a total redo. Skins would be removed. What is the max r-value and material or combination of materials others have used? I am not dead set on foam. I just thought foam would be one of the higher r-value materials.

I have no idea about the R values. I do have a '64 safari w/new fiberglass insulation and a '64 Avion T28 w/original foam sitting side by side in the back yard fully exposed to the environment. Under the summer sun the Avion is very noticeably cooler inside. In in heavy rain the Avion is much quieter inside. Even with those comps I'm still going with fiberglass in the '62 Ambassador rebuild because just can't see enough benefit to justify the potential problems. Sunny days I'm not sitting inside, rainy days I like the sound. If its late season cold and I need the heater I have to open some ventilation to avoid condensation negating the R value anyway. Fact is fiberglass has worked well enough as long as it isn't between the floor and the frame. But that's another debate.

[Ringoo7]

Are you saying you have condensation when using the heater in your Avion? If I use spray foam, it will be sprayed on a barrier material to form panels that can be removed to access wiring.

[putback]

The avion is used often for early spring fishing and late fall hunting in the northeast so the furnace is used often. Condensation under these circumstances is serious. On a typical 35/40 degree night with 4 people and not well vented not only the windows are wet in the morning, the lower 2/3rds of exposed interior walls are dripping water. Have used the safari under same conditions w/ 3 people and only have to crack a roof vent. Size and layout are different between the rigs, both have forced hot air furnaces. For an extreme example we've taken the fiberglass insulated safari, all water systems dry, ice fishing. That's on the lake, mid winter, sub zero nights. We have iced windows, entry door ect, but stay warm w/ only minor condensation. The only interior cooking allowed is coffee, much more does cause problems. There will be pros & cons to whatever you use to insulate. If summer heat is the primary concern foam may be the answer. There's no doubt in a side by side comp in the summer sun foam is way ahead of glass.