---
title: Ice Box Design - Page 3 - Main Forum
date: 2015-11-26T00:33:23Z
source: http://messing-about.com/forums/topic/7582-ice-box-design/page-3
tags: travco, refrigeration

---

On the foil vaced Celotex, I'd be curious to know what the structural load bearing characteristis are. As near as I can tell, all ice box designs are "free floating" which is to say the interior ice box itself is structurally isolated from the containment box. Wood or anything else that might be used to support it would also conduct heat and cold, so the insulation itself has to bear the load, which is a "live load" when you are talking about 40 to 50 pounds of ice and contents banging around inside the box. If Celotex can handle it, that might be a way to go. Several layers would mimic the foam/foil combo of the Pardey system (which is not their system.........they copied it from a Newport Beach, CA metal working shop that builds stainless steel tanks and stainless lined ice boxes for fishing boats).

I did some checking and the Foamular 250 (25 psi) product is the highest density product available locally, without making a special order (full bundle of about 25 sheets or so). But it looks like that would be adequate to be structural for this level of load.

BTW, almost any reasonable sized box could be built from two 4' x 8' sheets of foam and they sell locally for $26 per sheet or $52 for two. A comparable quantity of the 2 part foam (8 cubic feet of 2# foam) sells for about $70, plus shipping. In the big picture, not much difference in cost, but what there is leans in favor of the rigid foam insulation.

The only complication I can see, is if you go back through this thread and look at the pvc drains I used, building one of those into the rigid foam insulated box would be a neat trick. You could leave a bit of a gap and use the two part foam (or can of spray foam) to fill in around that. Most drawings of ice box systems I've seen drop the drain pipe straight out the bottom and put the loop outside (and below) the insulation. Simplest to build, but among other things, that puts the outfall low in the boat so it either has to drain into a small container that has to be dumped, or as some try, into the bilge. Draining into the bilge is nearly universally condemned as a bad idea (organic matter in the melt water will stink to high heaven). Some will pipe it to a bilge pump to be lifted out.

My hope was to elevate the box and drains just enough to get them above the water line to allow gravity to take care of it.

On the high end expensive vacume panel ideas, the maker of those was apparently Glacier Bay. A check of their website (different from the link in Calder's book) suggests they no longer make these. In fact, it looks like they are out of the insulation business alltogether.