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I think someone also mentioned to me that they tried to clear a head clog with this solution and it ended up blowing up the lines or tank or something. Bad bad!

I *think* that Yanmar decided they didn't need any zincs in that cooling system as they used "o" rings to isolate the exchanger... again memory might be flaky. Maybe due to too many muriatic acid fumes?

George

[quote="THATBOATGUY"]I think someone also mentioned to me that they tried to clear a head clog with this solution and it ended up blowing up the lines or tank or something. Bad bad!

That would have been me, but the head wasn't clogged, I was "simply" trying to get rid of the calcified buildup that was growing inside the waste lines.

The muriatic attacked the nitrile rubber in the pump, turned it into a shrunken crispy black "potato chip", and I had no way continue pumping to clear the lines. The acid (which could no longer be flushed through the lines) continued reacting and dislodged enough stuff to plug the outlet end of the line.

The resulting pressure buildup blew the Y-Valve & the pump body to pieces. Anticipating what would happen (once I could no longer pump anything and hearing the reaction continuing in the black rubber hoses), I put a garden hose into the bilge and turned it on to dilute what I knew would inevitably end up there. It took about half an hour, by which time I had turned off the hose. The bilge pump handled the mess with no problems.

Replacing the "middle" of the waste discharge system took two days of my time and several hundred dollars.

Not one of the high points in annals of boat maintenance.

I now use pickling vinegar (regularly). I don't expect to blow anything up with that.

Ouch!!!

Yes white vinegar is the way to go on installed systems. I do use muriatic acid on frequent occasions to clean heat exchanger tube stacks at work, you have to be careful with Yanmar ones though as some have an aluminum sleeve surrounding the tubes. Muriatic acid and aluminum is also a no-no.

I'm not sure what the machine shop uses in their tank but most of us gear heads learned by like age 16 that if you want to re-use your cam bearings you tell the engine shop about it before hand or your block comes back all clean with the cams missing! heh heh They have another tank for aluminum stuff.

I certainly learned from Johns mistake, even if I couldn't remember the source. Don't use it anywhere it might get contained. I worked with explosives for nearly two decades in the military ranging from .22 rounds to nukes so I have a deep lingering respect for what contained chemical reactions can do.

George

When I first got my Freedom a mechanic told me to change two thing periodically. The raw water impeller every year and the mixing elbow every five years.

I also have had continuing problems with over heating at 3,000 rpm, in warm water, and warm air. This year I added a 4" exhaust fan that seems to have eliminated the problem. I also measured the engine compartment air temperature in the upper forward starboard corner. It got up to 155 degrees F. Mechanic says it should be around 120. Trying to figure out how to get more air intake.

My wife thinks we should use the exhaust as a clothes dryer.

Jim Demerest
F36/38 Lady of Remes

One thing that can increase engine compartment temperature is high output alternators, particularly when fitted with external regulators. Unfortunately this high heat also causes the output from the alternator to drop but by the time this happens it's too late. When fitting alternators over 100amps we recommend a 4" intake and outlet for engine compartment ventilation.