# FSK vs AP Facing



## waldo563 (Apr 26, 2009)

I have been using unfaced Johns Manville JM814 for my room treatments up to this point. However, I am now considering treatments for the rear of my room and my understanding is that it is best to use some sort of bonded membrane on the panels facing the room. All I have seen discussed is FSK faced panels but it looks like the JM814 is available with FSK or AP facing. Here are the descriptions.

FSK Reinforced Foil and Paper (Foil-
Scrim-Kraft). Aluminum foil reinforced
with fiber glass yarn and laminated with
fire-resistant adhesive to kraft paper.

AP (All-Purpose). The AP facing is white
kraft bonded to aluminum foil, reinforced
with fiber glass yarn. The kraft paper is
laminated with a fire-resistant adhesive
that minimizes the possible corrosion of
the foil.

It appears that the only difference is that the AP facing is white instead of aluminum which would be less likely to show through the fabric. Does anyone have any experience using the AP facing or know if it would perform differently from the FSK. Probably a longshot but thought I would ask anyway.


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## bpape (Sep 14, 2006)

What you're describing as AP is actually normally referred to as ASJ (all service jacket).

Both work very similary but ASJ will require a more serious adhesive to work rather than FSK.

Bryan


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## waldo563 (Apr 26, 2009)

bpape said:


> What you're describing as AP is actually normally referred to as ASJ (all service jacket).
> 
> Both work very similary but ASJ will require a more serious adhesive to work rather than FSK.
> 
> Bryan


Bryan,

I'm not sure why I would be concerned about adhesive. As long as they perform similarly acoustically, I think the white AP/ASJ facing would blend in better behind the light colored muslin covering I'm using.
Thanks


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## eugovector (Sep 4, 2006)

The simple panel design is to use 3m adhesive to glue the fabric directly to the fiberglass instead of building a frame.


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## waldo563 (Apr 26, 2009)

Thanks for the explanation...I built all of my panels with some sort of frame but I guess that's another way to do it.


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## bpape (Sep 14, 2006)

waldo563 said:


> Bryan,
> 
> I'm not sure why I would be concerned about adhesive. As long as they perform similarly acoustically, I think the white AP/ASJ facing would blend in better behind the light colored muslin covering I'm using.
> Thanks


Sorry. I agree. Either is fine. The AP is just a different finish that doesn't necessarily take adhesives the same way.

Bryan


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