Foil backed bubble insulation

[fwitiw]

Matt94gt... How'd it go? Squeaky? Now that its spring, have you camped? Thanks for sharing!
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77 Westy 2.0
78 Transporter (no engine yet!)
71 Beetle

[matt94gt]

[quote="Clara"]

[Clara]

[quote="matt94gt"]

[esde]

[matt94gt]

[Clara]

from VW technical bulletin:

[Thin Metal]

Home Depot does not stock the bubble wrap as in the past but you can however order it from them online.

[matt94gt]

So I insulated the bus today. Did something new, styrospan 1" with a true r5 plus the air should be a little more.

It has a tounge and groove which worked in my favour.

_________________
72' Sunroof Bus - Kansas Beige
http://www.vw-mplate.com/mplate-21257.htm

Build thread:
http://www.thesamba.com/vw/forum/viewtopic.php?p=7257521

[Clara]

[matt94gt]

[Don66bus]

Clara,

You are correct. When you have a bare, hot, metal surface, and you put insulation against it (bubble wrap, old carpet, cardboard), you are not going to feel the heat as much. The first increment of insulation is the most important. Foil bubble wrap is about R1. So is an enclosed air space (more or less), such as the space between the interior panel and the body. If you want to increase the comfort of a bus in cold or heat, add insulation. The higher the R-value, the less the heat loss. Bubble wrap has the lowest R-value of any product you can buy. That may still be enough for your needs.

[Clara]

[Don66bus]

I have not tested car insulation but I have managed research and testing on house insulation. The foil bubble wrap products do not insulate well and manufacturers usually lie on their websites. Here is one link to research we did years ago on these products: http://www.noutilitybills.com/PartsAccessories/Piping/BFIUnderSlabInsulation.html

That data shows that the bubble wrap has about R1 in insulating value as opposed to the R5/R13/R21 claimed. There are ways that a foil sheet can provide some higher insulation but it is usually hanging in a cavity with air on both sides, which is unlike any sort of automotive application.

Roxul, as much as I like for houses, will lead to condensation and rusting just like fibreglass. Do not use it.

A vapor barrier/air barrier material properly glued to the inside of the body (with no air gaps) should avoid rusting problems, but could cause difficulties if you ever want to weld or repair that metal.

[matt94gt]

I think EZ cool is the way to go then, I think ill bite the bullet and order some.
_________________
72' Sunroof Bus - Kansas Beige
http://www.vw-mplate.com/mplate-21257.htm

Build thread:
http://www.thesamba.com/vw/forum/viewtopic.php?p=7257521

[Eric&Barb]

[matt94gt]

[Eric&Barb]

There are three ways to insulate, that come to mind.
1. Trap lots of pockets of air in a substance so heat transfer is slowed way down, but this requires more thickness space.
2. Reflective material (Apollo lander lower stage was gold colored to reflect heat), this takes a lot less thickness.
3. Vacuum, but that takes rigid walls like glass tubes to work.

Going by the R values from Reflectix and EZ cool it looks like the latter is better. Maybe this is due to the added foam, and since both are reflective they are the same in that way.

1/2" thickness should leave a good air gap between the inner paneling and the outer sheet metal for air movement.

Not liking the styrospan due to squeaking and the stiff board like factor. What fire rating does it have??

How much area coverage for a $1700.00 roll of the 3M stuff?
_________________
In Stereo, Where Available!

[esde]

The solid insulation works well, but lends itself more to being layered into flat panels, where it can be fitted tightly. In a bus, with the slightly irregular curve and shape, fitting it will be tough. And as you noted, it squeaks. I would bet it sounds like a hundred mice while going down a bumpy road.
As for bagging the insulation, it's commonly called "fully encapsulated" when using fiberglass or rock wool batts. Perfect for keeping the insulation fibers out of the atmosphere, and the atmosphere out of the insulation.

[matt94gt]

[esde]

I'll throw a few cents into the ring:
The Roxul that's sold for home insulation can and will absorb moisture (condensation). I've seen it, no way I'd use it in a bus. Looking at their site they do offer a marine grade product with moisture resistant material
http://www.roxul.com/products/marine/sl+300+boards+and+slabs+(acoustic+applications)
Maybe, a better product. Really though, you have two ways to approach insulating the voids. One, you completely fill the void with a closed cell insulation. If there is no air gap, and no humidity absorbed by the insulation (as it's closed cell), then there will be no opportunity for condensation on the inner surface. Or, you plan for an air space, and air movement through it, and just insulate the back of the interior panels.
There's a ton of info on insulating campers here, under expedition vehicles
http://expeditionportal.com/forum/
With the bus, you'll never seal up the skin completely because of all of the channels. I'd glue the bubble panels to the back of my interior panels, or use loose insulation in plastic dry cleaning bags fastened to the back of the panels. Having some air gap between the outer skin and insulation works in your favor also, creating a "thermal break" between the outside and inside surfaces..
Great stuff, and most other foam stuck directly to metal panels usually ends with disappointment.
SD