Closed cell spray foam

[mothercoder]

Is closed cell spray foam okay to use or will it cause the same rust problems as open cell?  What's the cost compared to 1/2" polyiso?

 

[waldenbound]

Everyone says spray foam locks in moisture and causes rust issues. I've learned to regard spray foam=evil.
I used 1/2 poly iso, it slightly flexes enough to fit the curved walls.

 

[johnny b]

That is not what 'everyone' says.
OPEN CELL foam, such as Great Stuff in the single spray cans will hold moisture and create rust issues.
CLOSED CELL foam does not hold water and is an excellent product for insulating a van.

That said, the DIY 2-part closed cell kits can be tricky for a first timer. By the time you gather up the REQUIRED safety gear which consists of a full Tyvek suit with hoodie, certified respirator, foot booties (or shoes you can throw away), goggles, a few pairs of nitrile gloves, and a foam kit for 200 square feet, you'll be in approximately 400 bucks.

Polyiso sheets are cheaper, easier, and less messy. Foam is sticky as hell going on, so proper masking off of everything NOT to be sprayed is very key....drop cloths, tape, masking paper, etc.

Search in the 'insulation thread' to find many discussions on this.

A friend in the construction biz who could point you to a professional foam guy willing to do a 'side job' would be the best way to go if the price were right.....otherwise, the polyiso sheets are the way to go.

IMHO

 

[mothercoder]

That is not what 'everyone' says.
OPEN CELL foam, such as Great Stuff in the single spray cans will hold moisture and create rust issues.
CLOSED CELL foam does not hold water and is an excellent product for insulating a van.

That said, the DIY 2-part closed cell kits can be tricky for a first timer. By the time you gather up the REQUIRED safety gear which consists of a full Tyvek suit with hoodie, certified respirator, foot booties (or shoes you can throw away), goggles, a few pairs of nitrile gloves, and a foam kit for 200 square feet, you'll be in approximately 400 bucks.

Polyiso sheets are cheaper, easier, and less messy. Foam is sticky as hell going on, so proper masking off of everything NOT to be sprayed is very key....drop cloths, tape, masking paper, etc.

Search in the 'insulation thread' to find many discussions on this.

A friend in the construction biz who could point you to a professional foam guy willing to do a 'side job' would be the best way to go if the price were right.....otherwise, the polyiso sheets are the way to go.

IMHO

I wasn't planning on doing the spray myself.  A guy approached me to do it as a side job but since posting this he gave me a quote of $700 and I think that's way high.  I want to do this right but also without breaking the bank.

 

[BradKW]

I've done many spray foam applications professionally, and given the product cost, preparation, and likely exposure to really nasty chemicals, $700 is cheap. If someone would actually apply it to a uniform thickness and prep/clean-up properly, $700 is a great deal.

Worth mentioning that "great Stuff" spray foam in a can is actually closed cell foam, not open. That said, it is not nearly the same product as 2-part foams and I have some good theories as to why is seems to "cause" rust. A real 2-part spray foam applied to metal is about the best thing you can do though. Some people seem to feel there are outgassing issues, but not anything that I've noticed personally.

 

[Mobilesport]

I agree , $700 is a great deal.
I used to spray foam but we always sprayed it into enclosed spaces and it would 
expand and fill all the voids  , the trick was to know how many (seconds) "on time"
to spray for a given size void , if I were to spray a van I would put wall panels up first and
seal all edges and put mold release on the inside of the wall panels , drill a 1 inch
hole in the panel and calculate how much foam I want to spray in a section and
do it sections at a time , after the foam dried for 24 hours I would peel away the 
walls and install new paneling. 
If the wall paneling didn't get ruined I would  probably  reuse it , may not even peel it off.

 

[Mobilesport]

I wasn't planning on doing the spray myself.  A guy approached me to do it as a side job but since posting this he gave me a quote of $700 and I think that's way high.  I want to do this right but also without breaking the bank.

A van would be a pita , a box truck would be easy, is $700 quote for just labor or
the entire finished job including materials? ?