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stain · 09-08-2009, 08:24 PM

I need a little help at this point of my restoration ... I can not decide what to use for insulation for my Airstream . I would like to keep it as quite as possible ,so I was thinking spray foam and I was wondering if anyone has used this with good results... I have looked into reflective bubble but dont know how this will hold up for sound transmission ...I dont really want to use batt insulation as it was a very smelly after 50 years... so if anyone could point me in the right direction I would be greatfull...

Also I have all of my inside skins off and want to take care of any leaks from the inside so what to do ??? thanks in advance stain

Roadtoaster · 09-08-2009, 09:44 PM

I think the general opinion on this Forum is the spray insulation will crumble over time due to vibration, etc. Can't answer about fixing leaks from the inside so maybe an experienced restoration expert will join in.

53flyingcloud · 09-08-2009, 10:09 PM

I have never used foam spray..But, and maybe it's just me..As good as spray foam may seem to be, it does open issues of "smell" associated with some form of formaldehyde in foam spray agent. Finally, the other major issues is: It could be that you or, another owner down stream that might need to make changes to wiring or panel/leaks/etc , I can see a problem with trying to clean out all of this foam first. It just seems to be too final of an approach for the intented use of a product..(namely, the airstream).
IMHO..If it were me, I'd look at another product with similar results but, that has an open end to rework at a later/future date.

Wabbiteer · 09-09-2009, 01:30 PM

Look at Prodex Foil-FOAM-foil versus the bubble style (Prodex Products : Prodex Total Insulation : Online sales of Prodex Insulation.)

I've argued against foam before but was yelled down by "10 post wonders" here on the forums and quit responding to foam questions.. but here goes anyhow.. .

If a foam Manufacturer (Tigerfoam, etc) would do there own project AIRSTREAM trailer I might consider it - Just the steps required to prep the aluminum shell cavities would be dizzying...

1. Alkaline degrease
2. Rinse
3. Mechanically remove oxidation
4. Rinse
5. Self-etch primer, applied as soon as possible after the rinse.
6. Top Coat

Primer could be a Chrome or Iron Phosphate to a coating weight of 50 - 125 milligrams/square foot to guard against a perpetual moisture intrusion situation - and having primer bite well enough the foam will not have a better grip on it and peel it away would take some serious engineering.

The interior over spray parts that get trimmed would have to be surface sealed also, very good chances of live water and 99% humidity existing for weeks on end, water freezing and bursting foam cells repeatedly etc...

The liabilities may weigh evenly with the benefits I don't know.

I bought cases of 2" thick fiberglass "Handy-Rolls" (2' x 5'.. gads what a rip-off even at 90% off full price!) for 10-cents on the dollar when a Home Depot closed and will be putting fiberglass back ALONG with sn interior layer of Prodex taped over the shell ribs...

VIKING · 09-09-2009, 03:23 PM

Hi Stain, and welcome to the forum. I second the idea Wabbiteer put forth, using Prodex, but with a slightly different application. The bubble foil stuff apparently doesn't hold up to the extreme temperatures inside of an Airstreams walls. The high temps cause the bubbles to deflate and you lose insulation quality. Spray foam would be a nightmare to install without causing bulges and would cause problems down the line with repairs.
Wabbiteer, if you put 2-1/4" of insulation into the 1-1/2" thick cavity it will not work as well as intended and it will probably put a visible bulge in the panels when reattached. If the Prodex is placed over the ribs it will cause the existing rivet holes to become misaligned and the skins to fit incorrectly. I'm not trying to discourage you. I thought of the same idea a couple of months ago myself and determined that it would cause me problems if I proceeded that way.
I used the prodex with great results and I recommend it regularly. I installed the first layer with 2 sided tape, to the inside of the exterior skins and foil-taped the perimeter of each piece to the ribs. The second layer was more difficult. I cut pieces of prodex to fit into the cavities a little loose, then I pushed them into place and put a piece of foil tape onto the face of the ribs, hanging halfway into the opening where the prodex sits. I then stuck a piece of tape to the face of the prodex and used it to pull the prodex forward against the back of the tape I put on the ribs. This leaves me with a 1" airspace between the layers of prodex, which give me something like 38 db of sound insulation.
I hope the descripition makes sense to you. If not, let me know and I'll show you some pics of what I did.
Rich

Wabbiteer · 09-09-2009, 05:38 PM

Thanks for looking out for my project, counts a lot and I appreciate it.

I seem to have misstated or been misunderstood somewhere. I don't plan to use prodex in between ribs and liners...

I understand the bend radius changing, I do have dense 1.5~mm silicone sheet I would like to try to make as a thermal barrier but I doubt I can anchor it correctly.

Maybe - One way to make the interior liners work over a product like Prodex would be use stand-offs to ensure the rivets crush down metal to metal solid, then motion vibrations wont cause them to fail?

My 1973 shell ribs provides at least a 1-3/4" cavity and the "Handi-Foam" is a full two inches only in print, it will be lucky to maintain an even 1-1/2" loft.

Prodex is 5mm + or - 0.5mm so its 0.20 inches to add into the stack.

A point to mention is compartmentalize the air spaces left when doing an air-gap double layer, reduce the chimney effect in that dead air space will reduce air movement ie: keeping heat in the walls longer in winter, and cold in the ceiling longer in the summer. Sorry if its hindsight for you but its truth.

I will check back later - Dinner date in 24 minutes~~!!!

stain · 09-09-2009, 11:09 PM

Thanks wabbiteer for the pointer towards this Prodex product.. I like the - 38db Viking has with the air space.. but I do live in Canada and it can get cold up here !!! So I feel that the cavity should be filled .. thanks for all the help !!!! keep the options rolling ... and ideas ... or opinions .....

Xstream · 09-10-2009, 12:54 AM

I would suggest using Dynamat together with the Prodex. Dynamat is commonly used in car audio applications for soundproofing. Check it out at www.dynamat.com

stain · 09-10-2009, 06:25 PM

This product would cost a little to much for my liking ... if I won the lotto maybe !!!! works great I bet... thanks xstrem...

VIKING · 09-11-2009, 12:07 AM

Check out the technical data on the Prodex at the link in Wabbiteers post as it refers to the air space. It is not clear how much R-value any of these insulations have in our thin, aluminum-sheathed walls but from comparison in a normal house wall it appears that the Prodex has the others beat by a good margin, with the use of an airspace.
When I was installing it the temperature outside was in the high eighties, which translates to about 105 inside the un-insulated shell. By the time I got the first layer in it was tolerable inside. I did the second layer a couple of days later in similar heat, with an 8000 btu AC running inside the safari. I got the temperature inside down to about 65 degrees. I just got back from using it at the Black Rock Desert and I only had to use the AC one day out of nine on the Playa.
I used the extra Prodex from my install to make covers for the ceiling vents and windows so I can insulate the entire shell and blackout the interior on a sunny day to make it black as night, and cool. This was a big plus on the Playa because I tend to rest during the day and go out at night. I also can't say enough about how easy this stuff is to use. No itching, cut with a straight-edge and a utility knife, tape in place. Working areas like the end caps was easy and fast. They sell you the 2 sided tape and the foil tape along with the Insulation, so you only have one company to deal with and one bill. For crissake, I wonder if they need a sales rep in the central-California area?

Rich

stain · 09-15-2009, 11:59 PM

I think I will be using a double bubble reflective insulation,with an air space.. if it is not enuff I will get into wrapping hot water tanks for some extra Airstream money !!

stain... hey rich I would like to see those pics of your install..

VIKING · 09-16-2009, 11:06 AM

Here's a few pics of my insulation. The Prodex is different from the bubble foil stuff. It is more rigid and durable than the bubbles and it has better R ratings.
I paid $315.00 for everything to do my 22' safari with 2 layers of Prodex. Not a bad deal IMO. I will never use fiberglass again! It's just not worth the hassle.
Good luck Stain.
Rich the Viking

Birdwell57 · 10-07-2009, 01:14 PM

I've got most of the interior wall and $%#&ing fiberglass removed. I am hoping to have the shell off in the next couple of weeks. Looking down the road, and trying to get a good estimate, how many square feet of Prodex did you use for 2 layers?

VIKING · 10-07-2009, 03:51 PM

I purchased 700 sq.ft. and it barely covered my 22' safari with 2 layers. Keep in mind that I have more windows-per-foot than most(9 total), so you should adjust your figures accordingly. Also, get the tape from them. It was a better deal than I could find anywhere else.
Rich

Foiled Again · 10-07-2009, 04:14 PM

Last time I was at the factory, I asked the service techs about the foam in place insulation. The response - "Most crumble, but some may be OK.... until you have to replace a segment or panel. It sticks to EVERYTHING and almost doubles the labor cost to remove a panel. If we KNOW it's under there, we recommend just laying another piece on top of the damage and fastening it with aluminum rivets."

Paula

VIKING · 10-07-2009, 04:25 PM

Hi Paula,
This is not spray-in foam, but flexible polyurethane foam with reflective foil on both sides. It gets cut to size and taped in place. I have heard enough bad stuff about the spray-in to stay away from it. If you're interested in researching it more look at www.insulation4less.com It's called Prodex.

Thanks, Rich

pbearsailor · 10-07-2009, 05:00 PM

Quote:

Originally Posted by VIKING

I purchased 700 sq.ft. and it barely covered my 22' safari with 2 layers. Keep in mind that I have more windows-per-foot than most(9 total), so you should adjust your figures accordingly. Also, get the tape from them. It was a better deal than I could find anywhere else.
Rich

Rich, I've been planning prodex as well and put the order in this morning. Thinking about the double layer like you did, especially with your info that the one roll did your Safari. Can't really tell from your pics, did you run your wiring in the airspace between the two layers?

cheers,
steve

VIKING · 10-08-2009, 12:03 AM

Yes, that's exactly how I did it. I'll try to post some pictures of it if I can find some decent ones.
Rich

Birdwell57 · 10-13-2009, 07:11 PM

Are you also using Prodex under the floor?

Wabbiteer · 10-14-2009, 08:15 AM

I used rust-proof 'Monel' staples and Vulkem to install Prodex under the floor - a border strip two-inches wide around each panel, and a two layer Prodex center standoff to add more air gap and provide drainage if water ever gets between the floor and insulation.

I plan to add blankets on the spars stitched on with ty-wraps before it gets closed up.