Monday, February 19, 2018

Re-plumbing the Air Conditioning system

The Old (2 years) System

When I installed the AC system two years ago, I plumbed the Raw Water Pump with a hose from the Thru hull in the bathroom that ran all the way to the V-Berth, that's about a 18' run. I worked fine except that it would keep losing pump prime and the long hose would get blocked with build up ( barnacles, guck, etc.) and we would have to run barnacle buster through the hose to clean it out far too often.


Install a new Thru Hull in the Bow below the water line to provide Raw Water input to the pump.

Step 1. Here's the Sea Cock and Thru hull fitting. The Sea Cock is mounted on a backing plate that I made following the instructions on the Compass Marine Website. The SeaCock is secured in place by 3 bolts that have been cut down. So, if the seacock needs to be replaced some time in the future, I can simply undo the 3 nylon lock nuts, extract the bronze thru hull and remove the seacock. 

Step 2. I cut a hole with a 1" deep hole cutter from the outside into the hull in the V-berth.

Next, I sanded down the inside to create as flat an area as possible for the Thru Hull Flange to bed onto the hull.

The pic shows the hole and the sanded area. I did all of this while the boat was hauled out at Playboy Marina in January 2018

Here's proof of my screw up! The Thru Hull fitting in the pic above shows it as a mushroom headed thru hull. I screwed up by cutting it to the right length, well, nearly! The old adage, of Measure twice cut once! Well, I measured a half dozen times and cut once, but forgot to include the thickness of the hull! So it was off to WM and purchase a new Thru Hull fitting, but the only one they had was a flush model. So I had to cut into the hull to create a angled bedding for the fitting. 

I used my Cordless Dremel and 1/2" belt sander to get a near perfect fit.

The new Thru Hull held in place with the Boat Hook (since deceased)  for a dry fit.

Everything looked good, so Step 3 was to plaster the underside of the Backing plate with a Resin mixture with filler and plaster the inside of the hull with the same mix, wax the thru hull fitting and screw the seacock and backing plate down onto the thru hull.

I tightened it up from the outside by putting a pipe wrench on the sea cock to stop it turning and then, from the outside, screwing the waxed thru hull in as far it it would go.

After letting the resin cure for 12 hours, (next day) I removed the waxed thru hull, cleaned it off, applied 3M 5200 to the inside of the thru hull and screwed it back in place. This thing is water tight!

Now that the thru hull is fitted and the sea cock in place, it's time to work on the hoses to the raw water pump.

Here's a schematic of the AC Raw Water System. It includes the clean out system that uses Barnacle Buster.

I'll have to wait for the two Tee connectors to arrive before completing the system.

When complete, the AC Pump should prime easily because it will be only about 24" from the intake thru hull.

The Tee Connectors were waiting for us at home on return from the Chili Cook Off.

A quick trip to ACE hardware and I found the End caps and barbed connectors to complete the plumbing (the Black Tees in the Pic above) All of the Raw Water plumbing hoses will be double clamped.

Now that we have everything I can complete the project. Probably tomorrow (Thursday)

  • Install Tee between Pump and Discharge thru-hull
  • Install Elbow on Raw Water Thru-hull
  • Install hose from Elbow to 2nd Tee
  • Install hose from 2nd Tee to Strainer
  • Install hose from Strainer to Pump
  • Test for leaks
  • Run AC system and check for prime and leaks.

This pic shows the completed installation (with paper towel leak detectors in place beneath the Pump & Strainer connections)

The open hose that can be seen hanging down near the strainer is the fill hose for the AC Condensate collector. We put a 2gallon jug in place to collect the condensate and use the condensate to flush the head rather than use our Fresh water supply.

The Old Speed log transducer (shown with the wire attached) is no longer used, and will be removed the next haul out in about 2020)
The Pump is not mounted, I needed to know where it would sit before making the support shelf. Now that I do, I can cut a piece of Starboard and 3M 5200 Glue it into place beneath the pump, secure the pump with 4 screws through the AVMs and tidy up the electrical supply cable.

Just another view of the AC Raw Water Supply plumbing.

We had the AC running for a half hour and no leaks! WooHoo!

Now I can get rid of the odd bits of hose that I kept knowing that it might be handy when I do the re-plumbing job.

Note the White Cap (yellow label) , that's one of the two AC Flush system connections.

And the Strainer is now shown horizontal, we can see if water is flowing in the strainer.

Peggy wants me to install a lamp beneath the V-Berth to improve visibility, I'll buy  a couple of the LED Switch lamps from ACE Hardware.

This is the AC Raw Water Discharge Thru Hull and Sea Cock. The white cap is the port that will connect to the AC Raw Water Flush system to get rid of Barnacles inside the Raw Water tubing, AC Unit, Strainer and Pump.

Note how the Paper towel leak detection is totally dry.

As said before: WooHoo!

I should be able to get the Pump support shelf done over the next few days. Pretty simple really: Just a piece of Starboard, cut with similar angles to match the sides of the hull by the pump then glued into place with 3M 5200.

But right now - We have AC again!

See you on the Water.