Fresh water contamination.

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Oct 12, 2007
A friend purchased a boat and discovered the FW* was "winterized" with green AUTO antifreez.

He plans on flushing for etirnity , buy is there some soap or chemical that would help the removal?


The boat is too large and complex so simply replace the taNKS , PLUMBING , HEATERS ET ALL.

Good grief. Pump it all out, then wash with any good soap like dishwashing soap. Fill the tanks with FW and pump out, then refill and pump out at least*three more times with plain fresh water. That should take care of it. Be sure to pump through all the lines each time to get it out of there as well.
Once had a truck with big cummins in it with a bad oil cooler. Radiator was contaminated with oil and antifreeze. I used a good bilge cleaner to get the oil and anti mix out. After flushing 3 times the water coming from the system was clean and clear. I don't know if it will work for his water system but I know it will clean out most all traces of antifreeze then maybe some bleach to make sure. I'm not sure plain soap with cut it but anything is worth a try. Larry

PS Antifreeze and animals = a slow miserable death.* What does it do to*the humans.

-- Edited by LarryW on Monday 22nd of August 2011 06:30:25 AM

-- Edited by LarryW on Monday 22nd of August 2011 06:31:00 AM
The big truck mechs I know use Cascade to clean stuff out of radiators, etc. Dishwasher detergent does not foam like regular detergent.
If the antifreeze is propylene glycol it is no big deal, if it is ethylene glycol a good flush with clean water will remove it. Don't contaminate the system with soaps or solvents,if you do that you WILL have a problem.

Adding soap or other stuff to the mix will only make it very difficult to clean the system. Just drain as much as possible from the potable water tank and refill with clean water, run the system to clear the lines to each outlet. Either drain and flush again or just keep the hose flowing into the tank(s) and out the faucets to flush.
Old Stone wrote:... will it destroy the heating elements?
It shouldn't have any effect on them. Part of the job of glycol is to protect metal exposed to high temperatures and corrosive fluids like water. It cools engine parts and is mixed with the circulating water in hydronic heating systems that are heated by resistance elements.

The incident FF mentioned is a pain but it is only a problem for the couple of hours it takes to flush the system.
He is able to dump the FW overboard , so a 12 hour flush will be first try.
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