[C38] Refrigeration

[tdtron at earthlink.net]

Thanks for the kind remarks but everyone in this group has talents and I'm sure many are more sophisticated than my redneck low wage tech skills.  As far as improvements are concerned, I want to see boats with upgrades like Joe Launie's that need mega amps of electrical power just to power the toys.  Other of you have more investment in your winches than I had in my dink and motor.  A lot of what I did to my boat was because I was either too cheap or broke to pay someone else to do things for me.  Necessity is the mother of invention?

I am truly humbled when I read about some of the boats in this group and see how well they are preserved and equipped.

Getting back to tech stuff, I saw the vacuum insulation material Steve Ribble speaks of at a trade show but I have not seen it again in a few years now.  Nothing insulates like vacuum.

On our refrigeration insulation, we used urethane foam board on the outside of the box except on the hull side where we packed heavy duty waterproof plastic bags filled with Fiberglas insulation because we couldn't get the foam board in there properly.  We then insulated the inside of the box by making precision fitting pieces of 1" foam board which lined all sides and the bottom.  These pieces were held in by a precision force fit with no hardware.  These pieces were covered by pieces of Fiberglass sheet for protection epoxied to the foam pieces.

We used more foam to line the inside of the lids. We coated the lid foam with epoxy resin and glass to make it durable.  The lids looked original when in place since the insulation was on the inside only.  

Urethane foam costs slightly more than Styrofoam but it is fire resistant, chemical resistant, and has a higher R value than Styrofoam.

The last thing we did, and one of the most important, was to put a layer of reflective Mylar over the foam insulation in the engine compartment.  This reflective material reflects most of the infra red heat radiation which is a real problem with the insulation so close to the exhaust manifold and hot engine block.

With a cool engine we didn't see much improvement with the reflective material but if the engine was hot, the results were nothing short of fantastic.  You can now buy this reflective material anywhere, including Lowe's and Home Depot.  It isn't very expensive, doesn't take up any dimensional room like foam board, is easy to install, and it traps air in any voids left from an imperfect fit from pieces of the installed foam board. 

The only way to attach foam board to the outside of the refrigerator in the engine room is by cutting smaller pieces to fit one piece at at time unless you take the engine out to accept larger panels.  I installed a large screw-in access port in the forward bulkhead of the sail locker to make installing the pieces of foam easier, otherwise it is pretty much impossible to reach the aft side of the box properly.

I seem to have a knack lately to use too many words but the bottom line is to use the Mylar film after you have finished insulating.

Tom Troncalli




----- Original Message ----- 
From: Steven Ribble 
To: Catalina 38 Listserve
Sent: 9/23/2011 11:45:17 AM 
Subject: Re: [C38] Refrigeration


OK, I've got a new proposal for Association funding...we pay for Tom to visit all of our boats and see what improvements can be made! 

Obviously I'm kidding, but Tom is a great wealth of knowledge and I appreciate his continuing to share it with us.

Along with improving the refrigerant line, I had a conversation with a guy a couple years ago about some sort of insulation material (a rigid sandwich type with a vacuum core) that he claimed was the answer to keeping things cold.  While I don't remember the material, the point is that we need to be sure we're insulating the box well given it's proximity to the engine (heat) or all of these mechanical improvements will be marginal at best.

Steve R



-- 
Steve Ribble
207/852-0971
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://catalina38.org/pipermail/listserve_catalina38.org/attachments/20110923/594ecfb0/attachment-0001.htm>