Insulation?

[mbbarnhill2]

Hi, I have a 1976 Trade Wind that I am gutting. My question at this time is what is the best type of insulation to use for the walls vs the floor? Any help would be nice as this is my first rebuild of a trailer.

[Michael_Wild]

I am curious to get feedback from anyone who has used spray foam on their Airstream. I thought it would be the ultimate solution as it would fill every nook and cranny, provide the highest level of R value per inch, add rigidity to the structure and if closed cell soy based spray foam was used you get the bonus of a vapour/water barrier so any leaking riots become a thing of the past.

But then someone said the fact it is rigid, is a problem as the spray foam breaks down into dust due the friction that occurs when the trailer is in motion.

Is this a problem? Has your spray foam broken down over time?

[GMFL]

Not sure how much it would break down but would love to hear from someone who has used it

[Belegedhel]

There are several threads here on the forums that address this question. Best way to find them is to do a google search from outside the forums with key words like "airforums best insulation". You will see advocates for everything from the pink fiberglass to super-high-tech nano-spheres. The fact is, though, that you have 1.5" to work with, and a lot of single paned windows. So anyone offering you more than R6 or 7 is selling snake-oil, and it is probably Best not to over-think it.

good luck!

[Wabbiteer]

I was invited to bring my AS to a local vendors spray-foam worksite and he'd spray it... ONLY IF I had used a DIY froth-pac foam kit to apply 1/2" of foam over the entire shell before - with that barrier in place his heated-hose 3000-psi catalyst-kicked spray foam would not warp/wrack/ripple/wring/damage (much) the shell, or so he said.

If the aluminum absorbs the chemical actions generated heat then the innermost/first layer will cure to solid last, the last foam action will be wedged against & springing from the solidified foam vs. the exterior shell sheet metal so too much force gets levered against it the metal.

Also: Remember even a millimeter crevice will allow foam the foothold to give the potion-of-motion heave to both sides of the crevice, multiply expansion force by the length of the crevice so all the ribs & stays vs. the gaps in the outer shell metal things can get ugly. Cracks and crevices get caulked/taped before even a DIY-style foam gets applied.

I wire-brushed, degreased then acid etch prepped my 27' shell interior - then Alodine chromate conversion treated it to prep for foam; note here many degreasers are alkaline or contain phosphoric compounds that block chromate processes by modifying aluminum surfaces themselves, I learned that the hard way - use Simple Green Extreme only if you're getting serious about preserving aluminum!

Also, the acid cleaner contained ~1% hydrofluoric acid which does wicked things to living things especially those that have calcium in them so I was moon suited up. Worked good, lasts a long time.

That Fall I lost the weather and above 65°F temperatures needed to spray DIY foam - it did not get done. I'm thinking barrel stave cut of 1-1/2" sheet foam now...

[WhatidIdo]

Originally Posted by planBe

I am curious to get feedback from anyone who has used spray foam on their Airstream. I thought it would be the ultimate solution as it would fill every nook and cranny, provide the highest level of R value per inch, add rigidity to the structure and if closed cell soy based spray foam was used you get the bonus of a vapour/water barrier so any leaking riots become a thing of the past.

But then someone said the fact it is rigid, is a problem as the spray foam breaks down into dust due the friction that occurs when the trailer is in motion.

Is this a problem? Has your spray foam broken down over time?

I have a 1973 Streamline with closed cell spray foam insulation that was there from new.
It dose NOT stop leaks. (At least not completely) My biggest concern with my restoration is that it's hiding some smaller ones.
If it's exposed to enough water it erodes into little spongy chunks.
I'm still going to keep the insulation however because it dose seem to add a lot of rigidity to the structure and it dose actually seem to flex pretty well without deteriorating.

[Boxite]

Fiberglass batting (the pink stuff) is what is best. It can be fitted into whatever space you need.. and even if it gets wet from a leak, the water will still gravitate through it to the bottom and drain out. It can be EASILY REMOVED if there's ever a reason to get back into the walls. \
Foam that has adhered to the walls is a BEAR to get out and get the surfaces cleaned up again. Fiberglass is simple... pull it out...throw it away.

Sometimes it's better to not try to re-invent the wheel.

[rugjenkins]

It's personal preference! I used spray foam and love it. I do tend to go over board. But I sealed/caulked every nook and cranny. Many use polyiso which is a great option. One must weigh each one out and go with what they like.

[putback]

For the hull I use the yellow fiberglass insulation. Its what the heating and ventilation guys use to insulate ductwork. comes in one to three inch thickness. Been using 1 1/2 inch with reinforced alum backing. Its just a bit more dense than the pink. Easy to work, comes in various widths, reasonable price.

[Mx468]

I second using the pink "pink panther" fiberglass. Its easy to use and won't break the bank.