Pink Foamboard

[Steve Frederick]

Hello all!
I was working on Mike's walls today, and came up with a discovery. The foam I'm using has a thin plastic film on each side. This film will not bond well in a built-up system, glue does not bond well to it. I just peeled it off as I was ready to glue it in place. I didn't do any "destructive" testing, Just playing it safe!

[Guy]

Steve,

Each of the insulation companies have sites with info on their peculiar adhesive needs. Also try Larry at RAKA, he probably has a lot of knowledge about this problem. Remember that you still have to be concerned about small air spaces, try using either Great Stuff or Handi-foam sealant and adhesives depending on your foam formulation and amount of pressure applied to the glue up.

[Steve Frederick]

Guy, I know that epoxy and Gorilla glue, even Tite bond all work on the foam itself. I was just surprised to see the plastic film on the sheets of pink stuff!
I've built a lot of r/c planes with foam/glass with no failures...except run in's with the ground or other planes...air to air combat!!
I'm planning on building some fenders using foam/epoxy/glass..(Thanx, Steve W!!)I'm sure of the adhesives that I am using, just had a problem with that film. BTW, it doesn't sand well either! Works great without the film.

[steve wolverton]

Steve Frederick - I know exactly what you're talking about. I recently built a float for the towns Christmas parade. To run the lights/PA system I built a box that sat in the back of our police truck which covered a generator. While painting the foam (which was blue foam board BTW) I realized that it wasn't painting worth a poop. Then I realized that I was trying to paint the plastic not the foam. Then I realized that no one was looking so I peeled it off quickly and painted the foam. Then I realized I just revealed this to everyone.



Steve

[Guy]

DearSteve,

I figured your glue works. Was the plastic film there just to protect the foam during shipping, and sales or is it integral to the type of foam insulation ie, moisture/fire retardant? What brand and product type is it?

[Steve Frederick]

Guy,
It's Owens Corning pink board. I did a little test.. I took the film off a piece and I could snap it in half real easliy. With the film in place, it's a good bit harder to do the same. Maybe it's there to lend strength for handling?? When I have used foam board in a building, I nailed it to a wall or roof,(timber framed houses). I have not used glues, except for specialized hobby-type projects.

[mikeschn]

I wonder if that plastic sheeting is the vapor barrior when installing in a house? Of course all the rules change for teardrops!

Mike...

[Guy]

Dear Mike and Steve,

Just wondering exactly which Owens/Corning Pink you are using. They actually make 14 different "Pink" insulations. Some are commercial or contractor versions and don't have advertising on the foam

[SteveH]

I used two layers of the blue stuff from Lowe's, and it also had a plastic coating both sides. I figured it was for vapor barrier.

[Chuck Craven]

No it is there when it is used as sheeting on the outside of a building. It helps keep the roofing nails or staples from pulling through the sheet before the siding is applied. It’s a tough coat film, difficult to tare, should be on the outside when it is nailed.

Chuck

[Steve Frederick]

I guess when all else fails...Read the Instructions...
The film is there to prevent damage!!! Imagine that!!

[Scooter]

No it is there when it is used as sheeting on the outside of a building. It helps keep the roofing nails or staples from pulling through the sheet before the siding is applied. It’s a tough coat film, difficult to tare, should be on the outside when it is nailed.

Chuck

Now that makes sense.

[Chuck Craven]

Before they put the plastic film on it. The carpenters would nail up the sheets and the wind would tear it off.
It got to the point where none of the builders would use the stuff. The suppliers had to do something to help
keep it on the buildings. If there are high winds it still will get ripped off even with the film.
Chuck