Refrigeration- Making it Better

[WebWench]

We want to add additional insulation to the inside of our refrigerator/ freezer unit. We had to remove the PO upgrade because of it leaking.

The PO had lined the original fridge with 1"solid insulating panels covered with thick alum foil. He then covered these with marine plywood and then layered on some kind of while plastic. Sealing it all with silicone caulk I believe. It worked great until the silicone caulk started to allow water to drain down and totally soak the marine plywood. Then repeated defrosting the freezer probably made it even worse.

We tore it all out. The insulation looks good and can probably be reused....but we plan to add some spray foam between the pices to make it solid.

What would you use over this.? We...do not want to use anything that can absorb water again. Would be interested in seeing what others have done.
Has anyone fiberglassed the inside?

[rebel heart]

Mine was fiberglassed; it worked well. Eventually we just abandoned that and went with en Engel stand alone unit. Cut out some space and plopped it in.

[toddedger]

I just redid my box with spaceloft. I covered it with fiberglass panels and used 5200 to seal the joints. The space loft is interesting stuff. I dipped some in a bucket of water and it didn't soak any in. 5200 will grip much longer than silicone.

[Stevens 47]

Originally Posted by toddedger

I just redid my box with spaceloft. I covered it with fiberglass panels and used 5200 to seal the joints. The space loft is interesting stuff. I dipped some in a bucket of water and it didn't soak any in. 5200 will grip much longer than silicone.

I used this about 3 years ago. Made about a 70-80 mm layer around the old frp boxes. Sealed it with thick plastic sheeting. Then foamed it with high density foam. Works great keeps the box cold.

Jack

[Cheechako]

I have used white formica over ply before. joints sealed with white caulk.

[Celestialsailor]

If you do a search here in CF, you will find tons of info and examples of installations. I used 1" of Aero-gel on a f/g box I made from a mold and then after setting it in the space, poured foam all around it...about 3"+. Refer comes on for 5 minutes every 25 minutes.

[dugout]

Originally Posted by rebel heart

Mine was fiberglassed; it worked well. Eventually we just abandoned that and went with en Engel stand alone unit. Cut out some space and plopped it in.

How much heat does it exhaust in the gally/saloon area and what size did you go with?
Thanks

[rebel heart]

Originally Posted by dugout

How much heat does it exhaust in the gally/saloon area and what size did you go with?
Thanks

It's a pretty negligible amount of heat; both in cold and hot conditions I've never noticed any difference. It's quiet as a mouse as well.

I went with the little one, I think the 35?

[colemj]

By physics, it needs to exhaust as much heat as it removes plus more for the efficiency factor.

Mark

[skipmac]

First, avoid the spray foam in general since it will absorb water over time.

You don't say what the old insulation panels are, but unless they are high tech, expensive panels probably better to go with something new. There are lots of things to use that will do a good job, some much better but can be much more expensive as well.

I think the best bang for the buck is to buy standard Dow blue Styrofoam sheets that you can buy at Lowes or Home Depot. They don't absorb much moisture over time and have a pretty good R-value. Also easy to work with but be careful about breathing the dust when you work with it.

Lots of options for covering the insulation. You can go back with plywood again but as you found out, it needs to be well sealed. You can get fiberglass cloth and resin to cover it but that can be a bit messy and it could be a lot of work to get a good surface. However you can also buy 4X8 sheets of fiberglass sheathing at Home Depot to cover the foam. Cut sheets to fit, attach with epoxy and fill all the corners and joints with epoxy. Will never leak. If you have a few small gaps or holes where you run the copper lines or wiring you could use spray foam to fill these.

[dugout]

Originally Posted by rebel heart

It's a pretty negligible amount of heat; both in cold and hot conditions I've never noticed any difference. It's quiet as a mouse as well. I went with the little one, I think the 35?

Thanks.

[bstreep]

Just going thru this process. Contacted friends of ours (who you can hear Saturday mornings on Margaritaville), and both are engineers - she was one of NASA's top engineers before she retired.

They went with "blue" insulation which is the same as the "pink" insulation: Extruded polystyrene. The polysidocryanate is a better insulator - by a fraction - but much more likely to pick up water and it's just much harder to work with. Having looked at both and worked with both, the polystyrene is far easier to work with, and in a typical marine environment, is likely to out perform polyiso.

Polyurathane foam (aka Great Stuff) absorbs a LOT of moisture. This renders it pretty much ineffective as an insulator in a wet environment.

[SV Sea Monkey]

My boat came with blue board panels fitted around the inside. They fit nicely, but get scored over time and I wonder if they're not growing some nice germs in all those little nooks and crannies. If I redo it, I'll probably go with Aerogel sandwiched between layers of bubble wrap, with the edges taped with foil tape. A friend recently did this--it was a DIY job but looks very nice, kind of like a soft-sided cooler on the inside. The panels are removable for cleaning. If you're concerned about punctures you could add a more durable layer (perhaps thin HDPE--like those roll-up cutting boards) to the outside of the sandwich and vacuum seal each panel in plastic. In my case I already have the blue board panels to use as templates, but with panels small enough to fit through the lid it should be relatively easy to make some templates.

[skipmac]

Originally Posted by SV Sea Monkey

My boat came with blue board panels fitted around the inside. They fit nicely, but get scored over time and I wonder if they're not growing some nice germs in all those little nooks and crannies. If I redo it, I'll probably go with Aerogel sandwiched between layers of bubble wrap, with the edges taped with foil tape. A friend recently did this--it was a DIY job but looks very nice, kind of like a soft-sided cooler on the inside. The panels are removable for cleaning. If you're concerned about punctures you could add a more durable layer (perhaps thin HDPE--like those roll-up cutting boards) to the outside of the sandwich and vacuum seal each panel in plastic. In my case I already have the blue board panels to use as templates, but with panels small enough to fit through the lid it should be relatively easy to make some templates.

I used foam to form a lip around the box opening to support the lid and seals. Wanted to avoid the problem of soft foam getting gouged and dirty so looked at several options for coverings. After testing a few options I went with thin prefabbed fiberglass sheet that you can buy at Home Depot. Comes in 4' X 8' sheets like plywood, cheap and easy to work. I tried attaching it to the foam with epoxy and 5200 and went with the 5200. 5200 formed a stronger bond than the epoxy which was a little brittle and tended to crack while working with it, but went with epoxy to seal the joints and edges.

[Celestialsailor]

I'm not sure soft foam is the way to go. You can buy 4X8 sheets of FRP at Home depot. My friend did this and lined the inside of the box with it using 3M 4200 and caulking the seams.