Greetings fellow mariners,
is a cut and paste of a response I proffered in a thread a couple years ago. I am lazy and it is easier to do this than to retype it......
After growing up on power boats and monohulls, as well as owning several of each myself, I was a staunch shaft only guy and nary had a good word to say of saildrives. When we made the switch to cats I even specifically chose to only look at catamarans with traditional shaft drive and we ended up buying
a TPI Lagoon
35 with twin Yanmars and shafts. Loved that boat but sold
it two years ago to “upsize”.
Due to many circumstances far too long and boring to type here we ended up purchasing
a 1993 Solaris Sunrise 36’ sport catamaran
with twin yanmars and SD20 saildrives. Being anti-saildrive made it a difficult decision but the price
was far too enticing to pass up and being recently retired I needed a project
. Got it for a steal as it has been sitting unused for about 15 years and is in need of a complete retrofit. The engines have just over 600 hours each so barely used. Spent the first six months on the hard
, pulled both engines, saildrives, rudders, every thru-hull......etc.etc.etc and either rebuilt or replaced it all.
The port side diaphragms, which I am certain were both original from 1993 as I had to chip the factory paint
to get the bolts out, were in pristine condition. I replaced them all anyways, and kept them for spares, as I went through the entire saildrives including gears, bearings, seals......etc.
The starboard side was not so good. Through no fault of the saildrive design or equipment
it was a gooey soft mushy mess and was actually slowly allowing water to seep though prior to us hauling out. The previous owner, or perhaps one of the many brokers or fender
kickers that had looked at it prior to us buying
it had ran it with the diesel
return line removed from the fuel
rack and as a result the bilge had filled with about 6 inches of diesel oil
. It was full when I went for our initial inspection and helped the owner, actually I pretty much did it for him, bail it out and clean the bilge. I also pointed out to him the source of the diesel in the bilge and repaired it.
Long story short, the diesel bath didn’t do any favors to the diaphragms and had turned them into a gelatinous goo.
After removing and rebuilding the saildrives I am now a convert. I am no longer at all concerned about the “big hole in the boat” or the craftsmanship of the design. We do have water tight bulkheads well above the waterline for each engine bay which also boosts my confidence.
If you read all that and are still here........or if you have skipped to the end of my ramblings then the condensed version is....
Don’t let any oil/diesel or any solvent or petroleum products come into contact with the diaphragms. I have always been very diligent about clean engine rooms, I was a machinery technician in the Coast Guard, but I am now OCD, as my wife puts it, about keeping the bays spotless and the diaphragms free of any contaminants.
Just one poor mans prose,
Safe Journeys all,
Like the OP’s vessel, ours also has water tight bulkheads in each “engine room” which extends well above the waterline, even when heavily loaded or full of water. I also have installed large bilge pumps with Ultra float switches/alarms in each engine space, as well as the forward bilge compartments so that we now have a 3500GPH pump in each engine space plus a 2000GPH in each hull, amidships, as well as a portable manual whale gusher 30 and a spare 2000GpH pump with a 25’ wire lead/alligator clips for emergency
backup if and when a 12vdc power source exists. I have a coil of 10’ discharge hose with it in my “damage control kit” which, in my boat, is sufficient in length to reach at least one port or hatch
from any spot in the boat. You may perceive the above preparation as excessive and paranoid. No argument from me, do as you wish. After spending time in the USCG it has taught me to be over prepared in many ways. Not sure if any of that is valuable or useful, and I have no doubt that everyone here is much smarter than am I, so their opinions are of much more value than any I might offer, assuming I am of course allowed an opinion. I have been told that only those that meet some members here high level of intelligence and experience are worthy of posting
or providing guidance. With that, and upon further reflection, simply ignore the entire prose found above in favor of those that are willing to share the vast, impressive, unparalleled and amazing knowledge they possess as they are happy to tell you how much smarter, stronger, faster, more productive, and clearly more well liked, and how in general, have little or no use for us commoners of the world.
Safe Journeys to most,