Gas System

The attempt to fire up the new marine stove has led to an upgrade of the boat's gas delivery system.  The stove was not getting gas and I tracked the problem to the cylinder selection switch which worked in one position but not the other.  Replacing that switch would require the extraction of the entire gas delivery assembly so I decided to take the opportunity to replace as much of it as possible.

Starting at the gas cylinders the components are as follows:
1. Hoses from cylinders to manual selector switch
2. The manual selector switch
3. The gas cutoff solenoid switch
4. The pressure reduction valve
5. The hose connecting to the copper gas line that supplies the galley

The first item was not critical since I had replaced those hoses in Hawaii about 4 years earlier.  However, I had to assume that the other items dated from 1983 when the boat was built.  I was particularly concerned with the last item, a fairly shabby looking flexible hose.

It took a bit of searching but my friends at Gas Components Australia at 1/4 Panama St, Canning Vale were able to replace everything but the solenoid switch.  I can live (literally) with that solenoid switch because the only consequence of it failing would be the shutting off of the supply of gas into the lines.

New System in Foreground

New Case

Case Ready for Varnishing

The photo tells the story, with the old items at the back and the new ones at the front.  The black rectangular component in the back is the solenoid switch, that will fit between the selector switch and the new 2-stage regulator.

The old setup was terrible, with the selector switch hidden at the back at a bad angle and difficult to see.  I decided to build a new cylinder case and put the selector switch on top of the case, where it will be easy to see and reach.  Besides, the old case is literally coming apart at the joins because it was too small to hold the larger cylinders that were introduced after I purchased the boat.

I then purchased two new gas cylinders because there is no hope of the existing cylinders meeting Australian standards.   I purchased them from Bunnings (sort of an Aussie Home Depot) knowing that I can exchange empty cylinders at any of their branches and any day of the week.  They are 3.7 kg in size, which should be ample for coastal cruising. 

I then purchased a nice piece of 18mm marine ply just large enough to do the job for $42.  I took great care in designing which surface would nail into which in order to maximize the strength against the tendency of the cylinders to break out of the box.  I joined the edges with Sikaflex construction adhesive (waterproof, paintable) held down with 40mm long galvanize nails.  The photo shows the new case with the new cylinders and the regulator assembly in its future position.  The holes at the sides will be for hooking "ocky" straps shown at the right.  The case will be screwed into the lazarette floor.

The final photo shows the case ready for varnishing.  I decided to treat the wood with several coats of Danish oil because it will penetrate the wood.  Neither sunlight nor aesthetic beauty will be issues, given that the case will be hidden to one side of the lazarette.

The gas supply system represents probably the last dark and mysterious corner of Pachuca because over the years I have been forced to deal with just about every other aspect of the boat.  I departed on the circumnavigation in 2008 knowing that I had not checked out the gas system and hoping for the best, placing great reliance on the gas detection and cutoff safety system.  Fortunately I made it back to Fremantle safely with no line ruptures or regulator failure