Another Fridge Rebuild

[RaymondR]

There are a plethora of fridge rebuild threads in the site but I thought this one is different enough to where it may be of interest to other tinkerers so here goes.

Previous Marine Fridge Adventures

This is actually my third foray into boat refrigeration. The first was a build from scratch where I built the box and the condenser heat exchanger and a fridgy tech friend built the eutectic tank and we installed and piped it up together. It worked OK and the little BD35 would keep everything in the box frozen if you let it cycle continuously. It lasted about ten years before the compressor finally retired itself.

The second one was the installation of a kit in the same box. This was the most disappointing as it only lasted about nine months before a pin hole corroded in the very thin walled copper tubing from which it was fabricated. It then lasted about another two years before another hole, which I could not find and removed it from service. The BD50 from that unit is one of the ones I am using on this rebuild.

What I evolved during the second rebuild was a very good storage system involving sliding trays which allowed both a very high packing density whilst also allowing convenient access to everything in the box.

The sliding trays were constituted by plywood pieces which rested upon longitudinal cleats. Each plywood piece had a cut out which allowed various sizes of Tupperware containers to be suspended in the box at various levels. It was a good system and worked well so I decided to evolve it a bit further.

One of the problems with the arrangement in the extant vessel is that about one third of the aft end box extends under the bench top and built in dish storage and part of the forward end under the counter top so the top access is limited. consequently I decided upon a system of rolling trays using the SS trays used in steam tables in the aft end and the old system of suspended tupperware in the forward.

The image illustrates the ice box as it was originally.

[RaymondR]

The Box Build

Since I hate working with fibreglass and like working with plywood, epoxy saturated plywood was chosen as the build material and having pondered, remeasured, mulled and speculated on how to go about constructing a box within a box I took jigsaw to plywood and made a start.

The boat is an Island Packet 40 with a lot of very nice teak woodwork which I was extremely loathe to disturb knowing that I would never get it rebuilt anywhere near as nice. Consequently I decided I would build the new inner box on the work bench, cut it into pieces so that it would pass through the existing hatch, and reassemble the new inside the old.

My advice to anyone thinking of emulating this plan is to go and find another boat with an existing fridge you can live with. Even with all the measuring I’d done it required weeks of trying to get it through the hatch, cutting it up more, attempting to assemble it, removing, trimming, re-measuring etc. to get it to fit satisfactorily.

The images shows the box in one piece and also cut-up the bench.

[RaymondR]

The Rolling Trays

The steam table trays are available in a number of sizes based upon the subdivision of the length of the largest into halves or thirds of a number of depths. This allowed me to utilize two of the largest size as the eutectic tanks, which defined the overall length of the box, and then subdivide the storage trays into subdivisions thereof.

The trays are supported by SS frames onto the sides of which are bolted the ball bearing rollers. The rollers run on SS tracks formed by bending strips of SS sheet into U shaped beams which, on one side are supported by wooden slats bonded to the FG covered plywiid side. And, on the other, are riveted to the SS fronts of the eutectic tanks.

The images illustrate the three tray and two tray arrangements suspended in their rolling frames.

[RaymondR]

The Drain

The original ice box had a drain connected to a diaphragm pump which I decided to retain with an increased number of drainage points. One of the problems with the original was that it did not have any screen and if used without unloading the fridge completely to check for detritus the outlet pipe became plugged.

The new arrangement exploited poly pipe and fittings to provide four drainage points which all have SS mesh screens.

The image shows the underside of the new box bottom with the drain piping. A later modification was to replace the elbows on the end drains with T pieces and run the cross pipe through the sides of the box to allow the cross pipe to be cleared out using a dowel rod should it ever be necessary.

[OzeLouie]

Originally Posted by RaymondR

The Box Build

Since I hate working with fibreglass and like working with plywood, epoxy saturated plywood was chosen as the build material and having pondered, remeasured, mulled and speculated on how to go about constructing a box within a box I took jigsaw to plywood and made a start.

The boat is an Island Packet 40 with a lot of very nice teak woodwork which I was extremely loathe to disturb knowing that I would never get it rebuilt anywhere near as nice. Consequently I decided I would build the new inner box on the work bench, cut it into pieces so that it would pass through the existing hatch, and reassemble the new inside the old.

My advice to anyone thinking of emulating this plan is to go and find another boat with an existing fridge you can live with. Even with all the measuring I’d done it required weeks of trying to get it through the hatch, cutting it up more, attempting to assemble it, removing, trimming, re-measuring etc. to get it to fit satisfactorily.

The images shows the box in one piece and also cut-up the bench.

Interesting project Raymond and good to see the pics.
Not wanting to try 'teaching grandma how to suck eggs' but do you have some way to prevent cabinet cold air loss through the drains?

Also suggest some batons on the insulation side of the inner liner to fix the plates to,

Cheers OzeLouie

[RaymondR]

Hi Louie,

The drains come out the bottom of the old ice box and then rise up about a half metre to a diaphragm pump so there will be a water trap there to stop any air flow.

The plates are mounted on hinges on the bottom side and are situated in an alcove with about a 20 mm clearance. I'm hoping the warmer air will enter at the top and be drawn down the back and out the slot on the bottom by thermo syphoning action and hopefully discourage frost build up.

The image shows the inner face of a eutectic tank with the tracks the tray frames mounted on it. The hinges can be seen mounted on the near edge and the upper edge has screw plates which allow the tilt to be adjusted.

[RaymondR]

One of the problems I experienced having decided to install the new into the old without disturbing the counter top was to get the two pack polyurethane into the cavities behind the sides and ends. To overcome the problem I built a giant syringe out of poly drain pipe and fittings, a piece of dowel, a couple of pieces of ply and some soft rubber sheet.

The procedure followed was to mix the two packs, pour it into the top of the drain pipe, whack in the piston and inject it through 16 mm holes in the plywood sides.

The system worked well and the holes were plugged by epoxy gluing 16 mm dowel into the holes and cutting them off flush.

[RaymondR]

In Post #4 I included an image of the underside of the plywood bottom of the box with the drain plumbing. This also had to be cut into pieces to fit it through the counter top and then put back together in the box to install it.

The first image shows the end pieces in place with the centre out to allow the plumbing to be done. Then the center piece was installed, and then holes sawed in it to allow the two pack foam to be poured in.

After the foam had fully expanded to tops were trimmed off, and SS screens installed over the drain pipe ends and another piece of plywood epoxied on top to form the completed box base.

[RaymondR]

The rebuild was shunted aside whilst I renewed the deck on my dingy and health problems are beginning to intrude so I decided to purchase an Ozefridge kit to install as one of the two systems I am going to install in the box.

I purchased their AW480 condensing unit along with their largest eutectic tank, which has the same face dimensions as the tanks I am building for the second one.

So far the experience has been very good with them being fast in responding and getting the system moving to me. It arrived in very good order and when I opened the carton was very impressed with the care taken in properly packaging the equipment.

The appearance of the condensing unit and tank is exceptional and certainly the best of the four units I have had experience with so far in my mucking about with refrigeration career. The metal work is very proficiently done and if it all runs as good as it looks I should have no trouble with it.

The structural stuff on the box is finished and I will get back to filling screw holes and such and painting the box in preparation for installing the refrigeration equipment within a couple of weeks.

[Uncle Bob]

Originally Posted by RaymondR

The rebuild was shunted aside whilst I renewed the deck on my dingy and health problems are beginning to intrude so I decided to purchase an Ozefridge kit to install as one of the two systems I am going to install in the box.

I purchased their AW480 condensing unit along with their largest eutectic tank, which has the same face dimensions as the tanks I am building for the second one.

So far the experience has been very good with them being fast in responding and getting the system moving to me. It arrived in very good order and when I opened the carton was very impressed with the care taken in properly packaging the equipment.

The appearance of the condensing unit and tank is exceptional and certainly the best of the four units I have had experience with so far in my mucking about with refrigeration career. The metal work is very proficiently done and if it all runs as good as it looks I should have no trouble with it.

The structural stuff on the box is finished and I will get back to filling screw holes and such and painting the box in preparation for installing the refrigeration equipment within a couple of weeks.

Raymond, they are indeed good to deal with and as you say the product is top notch.

[RaymondR]

With rebuilding dingys, dodging floods the start on the winter cruise the fridge rebuild has not been making much progress. However having arrived in a place where I will spend five or six weeks at anchor I have managed to revisit the project.

In addition to the condensing unit being enclosed in a very well fabricated, all stainless housing. It very conveniently has all the connections required mounted on one end. Since I have decided to mount it on the forward lazarette bulkhead, which is the aft bulkhead for the galley, and where the refrigerator enclosure is situated. The waste heat from the condensing unit will consequently be kept out of the living spaces and in a place where it may assist on drying out wet gear.

The two hose tail fittings on the upper right side are for the cooling water supply to air/water condensing heat exchanger which I consider to be a very clever bit of design work.

The terminal blocks to the left of the water fittings are for power supply and thermostats and another fan and the two brass fittings to lower left for the refrigerant line connections. Ozefridge uses flare fittings on these service valves rather than the more usual diaphragm penetrating style. Consequently these will pass through the 1" penetration tubes into the box whereas the other type would not.

The image shows the condensing unit and just bellow the brass fittings is the penetration for the refrigerant tubes to the eutectic tank.

The only negative is the the control panel is mounted on the sloping top. However the Ozefridge folks have available for very reasonable cost a kit which allows the panel to be remotely mounted and the work required is only replacement of the panel with an SS plate which has a mounting for the DB25 plugs which connect all the electrics and electronics and the mounting of the panel somewhere in the galley.

[RaymondR]

The Ozefridge kit to relocate the condenser control panel arrived by mail with alacrity and on being unpacked was found to be complete.

The bracket which holds the socket on the condenser end of the extension cable fitted all the holes and all the required screws were supplied.

Black perspex has become my favorite instrument panel material it being easy to work and looks good so I knocked up a template and cycled out to the local window and glass provider and they manufactured me a mounting fascia for $50.

My Island Packet has a small recess in the aft corner of the galley right above the fridge and the plug on the extension cable fitted nicely between the outer hull and the inner liner.

Good easy project and it doesn't look too bad.

The first image illustrates the parts package, the second to it's right the arrangement as assembled on the condensing unit and the third the panel as mounted.

[RaymondR]

One of the inconvenient things about being a permanent live-aboard is that you permanently live aboard.

First coat of epoxy undercoat, only a couple more then a couple of coats of finishing coats.

There are a couple of places in a boat where it is difficult to do without, the galley and the head. Fortunately this boat has two heads and consequently when I wanted to change the toilets to macerating electric I was able to do so at leisure as I did them one at a time over a period of a year. The galley is a tougher proposition. However I was able to manage things and get a coat of undercoat into the new fridge box without getting it all over me and the galley.

[RaymondR]

Well the winter cruise is finished and Xmas will be out of the way in a few days and I will have run out of excuses to not finish the fridge rebuild before it is time to depart on the winter cruise in March/April.

Working with ones head in a box whilst epoxy is vigorously catalysing is not pleasant and whilst the good quality chemical mask does a good job of protecting the lungs the fumes do bring the odd tear to the eyes. Then it takes about two weeks for all the fumes to gas off.

However I am now doing a final fitting of the brackets for the SS rails, which the support frames for the steam table trays are supported from, and will then remove the rails, leaving the brackets in place, for the final two applications of polyurethane coatings.

Following the completion of the coatings work on installing and plumbing the eutectic tanks (holding plates) will take place. Then the fashioning the insulation of the lids.

The image illustrates the bottom set of trays rolled back under the counter top, it rolls forward for direct vertical access to the aft tray.

[GILow]

Interesting idea with the steamer trays. You've got me thinking.

What sort of compressor system are.ypu using to cool things?