Bubble Trubble

From memory,  it was La Paz Mexico that the boats Plastimo Olympic 135 compass developed a small bubble.  But it was during the heavy rolling below 50 S in my approach to the Horn that the bubble got bigger and bigger.  Fortunately the size of the bubble did not increase after my arrival in Fremantle,  but the matter had to be dealt with because the card was now very difficult to read.  Also, neither compass light was working.

One thing about boating is that it forces you to learn new things.

I removed the compass knowing nothing about it beyond how to change its lights.  I didn't know what fluid would be required, or how/where to inject it.

I got various suggestions about the fluid: glycol, baby oil, kerosene, and "compass oil", whatever that is.

At Yacht Grot Roger produced some clear fluid in a clean jar that he said was highly refined kerosene, with the assurance that it would mix well with the existing fluid in the compass, sparing me the trouble and expense of fully draining it.

Big Bubble in Compass

Rubber Membrane

Stephen arrived for an overnight visit on Sunday morning and soon we began our work.  I had dismantled the compass enough to identify the filling screw, which I exposed after cracking the epoxy seal on it.  On his advice I had also purchased plastic syringes at the chemist.

We worked for hours but try as we may we couldn't shrink the bubble beyond a certain point.  We stopped our effort with the thought of perhaps immersing  the entire compass in fluid to ensure that we could evacuate all of the air.

I was a bit despondent because even if we could shrink the bubble there was no guarantee that it would not return due to some leak somewhere.

In the afternoon Stephen helped me to join Ebay and link it to my Paypal account then we did a search for another compass.  Soon we identified a pitfall: There are at least 3 versions of Plastimo 135 compasses,  the "Offshore", "Horizon", and "Olympic",  different from each other and at different price points.  It took a while to confirm that I wanted the "Olympic", which was priced on Ebay at just over $620, a bit rich for my blood.  Later that night I found one Queensland priced at just under $400.

On Tuesday morning I  got back onto the web to find the Queensland company's contact information and stumbled on a compass at Whitfords Marine near Fremantle for $349.  I  phone up, they had one in stock, and they agreed to hold it for me.  Two hours later Stephen and I arrived, put the new compass and my old one side by side, and confirmed that they had identical specifications.  I purchased the compass and two spare globes.

Old and New Compasses

From our web searches we had concluded that "mineral oil" was the most likely compass fluid.  I needed more fluid because I had used all of the fluid that Roger had given me.  We stopped at Bunnings on the way home and found a liter of "paraffin oil" that seemed suitable.  It was clear, of light viscosity, and had  a neutral smell - certainly not of kerosene.

Yesterday morning I resumed work  on the old compass because I didn't want to simply throw it away.  I started off  by putting the compass in the freezer for 2.5 hours on the theory that the fluid would shrink, making the bubble bigger, allowing me to expel more air, then the remaining bubble shrinking as the fluid got warmer.  The flaw in this theory is that we discovered a rubber fluid-filled membrane at the base of the compass whose purpose was to allow for expansion and contraction as the temperature varied.  So how could the bubble size vary with fluid temperature given that the rubber membrane would do the compensating?

What finally did the trick, in my opinion, was that I discovered that the end of the syringe could seal the filling hole quite effectively with only a little pressure.  This enabled me to overfill the compass while I watched the rubber bladder expand, then allow the fluid to spit out when I released the syringe, bringing out bubbles of air with it.  After doing this a few times I reduced the bubble to the size of a match head, but try as I may I could not completely eradicate it.

Nevertheless the compass is now quite acceptable for use and had I not been able to source a new  replacement I would have reinstalled the old one, hoping that the bubble would not increase in size over time.

Spot the Bubble

My plan is to set up the old compass as an adornment in  my house which is already laced with nautical decorations.

I cannot complain about the compass problem.  It is with little doubt part of the Pachuca's inventory when she was launched in 1983.  The new compass has a 5 year warranty and will probably see me out, unless I live beyond 106.

Regarding the failed lights, I discovered that the wiring to the compass was delivering less than 3V.  I tracked the  problem back to the grounding in the electrical  panel.  The grounding had been set up before my time, to a white wire that was part of a bundle of white wires that would have been difficult to track.  I elected to earth the wire directly to the ground side of the switch panel and began to get over 13.5V at the binnacle.

Gas Detector Fixed

The gas detector failed ruing the recent overnight  passage to Bunbury.  Normally there would be an error light corresponding to the detector having the problem,  but this was a general alarm which I had never seen before. 

Controller Inside Cupboard

Paul and I bypassed the controller and supplied power directly to the solenoid switch in order to use the gas stove.

Sensor now at top left.  Old sensor at bottom right.

Sensor in Lazarette

I then managed to find a new replacement of the same make and model for an all-up price of $600, which seemed a bit steep but OK because  I would get  parts compatibility.

I installed new unit and got the same alarms signal, which indicated that the old controller was OK and the problem was in one of the sensors.  It turned out to be the sensor in the lazarette, between the gas cylinders.  I then re installed the original controller with a replacement sensor from the new unit that I had purchased.  That worked OK but then I made the wise decision of testing the sensors using a rag soaked in gasoline.  The brand new sensor in the lazarette worked OK but the one in the galley below the stove failed.  I then replaced it with the second sensor from the new unit.  I installed the new galley sensor in a position well above the sole because  the original position was too low and subject to soaking when the shallow bilge overflowed while the boat was rolling.

The $600 wasn't completely wasted because after using the new sensors I've now got in reserve a new controller and solenoid valve.   The spare solenoid is good because I once read a letter from a couple who were not able to cook for weeks because their gas solenoid valve had failed.

Cleaned and Protected Connections

After finished the gas detector work I cleaned the connections of the lightning protection cables at each side of the mast then sprayed them with Lanox.  The cables connect to bolts of the heavy lead keel.  There are also cables from the chain plate but they were clean.   I don't know if these measures ever protected the boat but I do know that I didn't suffer any lightning problems during the 5-year circumnavigation,

Battery Intalled

After returning with a 2-week bird survey expedition to the Great Western Woodlands I continued my effort to install the new starter battery.

Battery Job Finished

The photo above shows the end result.  The two gel batteries are back in the upper position, with posts and connectors clean.  Below is the single new starter battery, with wooden spacers on its left to fill in the void left from what previously a second starter battery.

Dead Starter Batteries

Terminals in Need of Cleaning

The battery setup goes back to Opua, New Zealand, in 2008.  We had departed from Fremantle in May with only three batteries, two sealed Delkor N120 800 CCA calcium sealed batteries, one each for the starter and house banks, and one deep cycle lead acid battery for the house.  This turned out to be woefully inadequate.  Night after night when crossing the Tasman Sea the gas detector would begin chirping at around midnight due to low voltage and at dawn the house bank would be down to as low as 10.5 V.


In NZ a consultant was brought in and the result was a house bank with 4 x Commander GDC232 230 a/h gel batteries and a starter bank with both of the Delkor batteries.  The mechanics were brilliant in their installation of the Gel batteries: two on a shelf above the starter batteries and one on each side of the cabin, below the seats.  This resulted  in excellent weight distribution, all below the waterline.

New Battery with Spacers at Left

The starter bank failed during the recent Bunbury Cruise so I removed them and had them tested by Battery World, which pronounced them well beyond dead.  (The worse battery held a CCA of less than 10.) The decision was to install one replacement starter battery, a Century N120 MF with 900 CCA and dimensions identical to the replaced Delkors.  It is a sealed battery frequently used for starting heavy industrial equipment.

I began the replacement project by making what turned out to be a big mistake:  I removed the Gel batteries from the upper shelf before extricating the ailing starter batteries below.

Gel Batteries to be Lifted

I began the installation with two wooden spacers on hand to take up these space of the second battery.  That went OK but as I expected, lifting the 65 kg gel batteries back into  position was beyond my capability, given that I had endured two weeks of back pain after removing the dead starter batteries.  The problem was made worse by the fact that correct lifting posture was impossible in the confined space.  I spent literally hours cleaning battery terminals and connectors while ruminating on what to do.  (Everything was so corroded that it's a wonder that I got any power at all.)

I finally got the bright idea of contacting Kim Jamieson,  the man who seems to do most of the pen rope work around the club.  Jim agreed to help and on the day I had a vast array of wooden blocks, planks, and even two car jacks to assist us in making the lifts without straining our backs.  Kim eventually did it his way, with a combination of good technique, various planks and blocks, and muscle grunt work.  (Thank you Kim!)

Then I stepped back and saw that I could have left the upper gel batteries and place and simply slid out the starter batteries below.  (DUH! You live and learn.)

Below the Cockpit

While the batteries were out I  took a photo of the below-cockpit space.

To the left is the  multi-layered copper strap connecting the Dynaplate outside of the hull to the HF radio tuner in the lazarette.

In black is the autopilot linear drive directly connected to the rudder post in the center of the photo. To the right in black is the mechanism that measures the angle of the rudder for the autopilot.