Reefer rebuild - building box in place

[jordanbigel]

So, we're at week 7 for our reefer/freezer box rebuild. We have the insulation in place (a combination of Plyiso/Cryogel/XPS) and we have 1/4" FRP Panels ready to be assembled in-situ (using Plexus).

It occurred to me that we don't really have a way to ensure there are no air pockets between the FRP and the insulation. So now I am thinking I need to spread some kind of adhesive sealant on the back of each FRP panel so form an airtight seal between the panels and the insulation.

I was thinking a gallon of FRP adhesive (Tightbond?) with a notched trowel and then brace them with a 2x4 or similar, while they are glued together.

Is this necessary? The previous plan was just to spray more 3M 77 between the panels and the insulation, but that will only hold them in place for glueing, it won't seal any possible air pockets (2 sides of the freezer are cryogel wrapped in 2mil plastic, it is an inherently un-even surface) so I feel if I don't put a layer of sealant in there I will have tiny pockets of air which will condense out to water once chilled.

Or am I overthinking this part?

THANKS!

[Bowdrie]

Originally Posted by jordanbigel

It occurred to me that we don't really have a way to ensure there are no air pockets between the FRP and the insulation.

it is an inherently un-even surface) so I feel if I don't put a layer of sealant in there I will have tiny pockets of air which will condense out to water once chilled.

Or am I overthinking this part?

THANKS!

No, you're not overthinking it, and yes, there will be lots of condensation behind the fiberglass.
Good insulative properties and elimination of condensate start by building outward from the exterior surface of a pre-made box.
You can achieve good results from the outside>in, but that requires pre-glassed foam panels that are suitably joined and the seams glassed over, or glassing the inside of the foam surfaces it situ, which is a miserable job at best.
Irregular surfaces?
You're between a rock and a hard place if you're trying to either glass over, or make panels fit with no air space over Cryogel.