don't know ABOUT PINK FOR AUTOMOTIVE USE.... I see you hvae two s older than my 32' Express

The R/V antifreeze is propylene glycol based without any additives to protect the engine. There is an automotive type propylene glycol with additives.

http://www.prestone.com/node/414?select_region=1

I have seen Mack trucks with propylene glycol antifreeze. They are usually in the food business.

It has always bothered me that I carry 6 gallons of poisonous ethylene glycol onboard and might spill it into the water at any time. I am going to look into this stuff for my next coolant change-out. Thanks for the link.

I would say in a non diluted state it won't freeze but h2o that you don't get out of your block,coolers extra raises the freeze point or slush point In the USCG i've scene the atlantic freeze and that is heavy salt water when winterizing I warm engines,drain block n coolers,restart on pink n run 5 gallons through . In a car you would be hard prest to get all the h2o out of the system then you still don't have lubricity for water pump

Jeff, Down here we have a few people with pumpouts on small trailers to service some of the small home docks and rv trailers that don't like to unhook to dump. Might check around the area where you have your Marinette on the hard and see if someone is available locally . Mark

Jeff:
your 32' Marinette should have a mascerator and self pump out fitting on deck next to the regular fitting.
The self pump out fitting is a regular garden hose fitting (female). A 5 gallon bucket and a length of hose and you're all set.

In Florida I do not have to worry about freezing, but there is a disadvantage to my setup. I have no way of removing "content" from the flexible tank (can I call it a "bladder"?) without a marina to suck it out. This could be a real problem in the Bahamas or places in the keys where there are no pumpout stations.

I notice, though, that there is a thread in the deck fitting that the marina screws their hose fitting into. It is a standard thread. Perhaps you could just screw a pipe into it for a one-time pumpout, if you can't get an RV oumpout guy.

I have a Whale hand pump that I don't really need as a bilge pump, and I was thinking that I could find the matching pipe for my pumpout and mount it to the hand pump so that I would be able to pump the tank out by hand if needed. I see folks with "Y" valves in the Bahamas pumping their tanks out on the outgoing tide, it is kind of standard practice, and necessary in a country without pumpout stations.

I don't feel too guilty about this. When the Disney cruise ship leaves Port Canaveral, they wait for the 3-mile limit and then dump tens of thousands of gallons of black water, leaving a streak that can be seen from the air. And such a cute little mouse, too.

I concur with the advice to put the higher concetrate stuff in the tank - not pink stuff - and make sure you run the macerator to get some AF into it and beyond. If the marina doesn't like the idea of pouring crud from your discharge outlet on its ground..get a really big bucket.

The white plastic original Marinette deck fitting has both a standard suction hole and a self-pump out hole that is a standard garden hose thread. Its' connected to a discharge mascerator under the v-berth that pumps out the holding tank up to the deck and into a hose and bucket (or sewer) instead of through the hull so it's legal. Doug, your model might be too early for this feature. I think it was added in response to the ban on through hull discharge.