IP IceBox Drain

IP-35 co-owner Beth asked me several question on rebuilding the Icebox on an IP-35 to provide for a freezer with spillover cooling to the reefer and installation of a drain.  Thought that it would be easier to post an answer here on the blog than it would be to try and create an MS Word Documents etc.

First, I no longer try to connect new drains to the existing drain plumbing.  Way to much effort and it usually leaks.  This method works well and I've used it a number of times with great success.

The first step in the drain project is to cut a template for the floor of the icebox.  I use 1/2, 3/4, or 1" foam insulation as this is easy to cut and cheap.  Due to the size of the IP iceboxes you will not be able to get the bottom template in in one piece so I start with 2 pieces, each oversized, then trim to fit the contour of the bottom.

When I rebuild a freezer I usually use 2 - 3" polyiso roofing insulation Roof Insulation as the base then cover that with another piece of roofing insulation - normally 1 - 2" thich but using the product that is sloped - Tapered Roof Insulation, slope of 1/2" per foot works well for the bottom of the box.  Assume, for the purposes of this document, that the piece of foam here is actually 2 pieces cut to fit the box floor layed side by side with the seam of the two pieces between the two drain pipes shown later.  The first step in the process is to decide where you want the drains in the floor and also the direct location to the lazarette (IP-32,35, 37, 350 directly aft into the Stbd Lazarette).

Cut out the first layer of foam to match the drain locations.  The foam is cut with a long blade snap  knife and should be deep enough to bury the 3/4" PVC pipe and fittings.  In a 3" thick piece of foam I like to go down about 2" so that I can get the drains down far enough for the vertical risers to be added later.

Once the first layer of foam is cut glue the 3/4" PVC fittings to the pipe.  A  SxT ell is user here on the left (Freezer Side on the IP-35) and then a SxTxS tee for the fridge.



For the vertical drain pieces I use a 6" FRP coupling which is threaded on both ends with 3/4FPT threads which I cut in half initially. This is the FRP coupling before it is cut in half.

75007-206 6" coupling









Make the PVC pipe long enough to go through the existing box aft wall with enough extra on the end so that it can be trimmed and a SxT coupling glued to the end for the hose barb fitting that will be needed to connect the drain to a sump pump. 

In this image the pipes and fittings are glued together and set into the foam base.  The FRP risers are threaded into the PVC fittings using 3/4" plastic close nipples and Teflon sealer tape. 









Next the top layer of foam is cut using a 2" hole saw so that the FRP risers are centered in the holes.  This piece of foam would also be in two pieces so that you can get it into the box and in this case I would make the fore/aft seam roughly centered where the 3" spillover divider would be placed.








Once the dry fit is made mark the FRP risers about 1/4" below the level of this piece of foam and FRP liner material and cut.  I use Teflon thread  tape on the close nipples to seal the threads.


After all of the pieces have been dry fitted into the box I glue the first layer of foam into the box and use great stuff and fill the voids around the pipe and fittings in this first layer of foam.  Make sure to fill the vertical risers with stoppers so you don't drop something in them as installation continues.  These same stoppers will be used later to seal the risers to prevent cold are from running out the drain! After the foam is cured trim the excess and then glue the top piece of foam (already covered with the FRP liner) to the lower pice and again fill the voids around the sides of the foam with spray foam.

The SxT coupling glued to the end of the PVC pipe once everything is in place.  This is for the hose barb fitting that will be used to connect the drain to the sump pump.

After the floor is solidly in place continue installing the remaining installation in this sequence - top next which will be screwed in place w 4 - 6 screws and then held in place by the rear, front and side insulation. 

Next you have to bend the flat plate evaporator and install in the freezer then install the spillover divider.  I assemble and dry fit the divider in several pieces as well.  In the case of the IP's mentioned above I slide in a 1/2" FRP lined plywood divider followed by 2 pieces of 2" foam (2 pieces because you usually can't get a single pice into the top opening and in place) and then the final 1/2" lined divider.

I may add additional info as this project progresses.  Like a long distance puzzle project!  Hope this is some help - any questions feel free to ask.