Almost a Big Mistake

[High Bidder]

Last year I winterized my boat engine with RV antifreeze. I thought i'd be environmentally friendly. Never again. Just for an experiment I drained some of the coolant this spring and placed it in my freezer. At 0 degrees it turned to slush. Not quite freezing but very close. Since my boat is stored inside a unheated garage and due to the milder winters here in middle PA, it never got below 10 degrees in my garage. Next year I'll use regular antifreeze and just flush it into a drain pan in spring. I won't push my luck.

High Bidder

[lineman49]

Actually, I beleive that is what it is supposed to do. I was told it will not freeze solid but will jell up like you said it did.

[Mickey Finn]

Actually, I beleive that is what it is supposed to do. I was told it will not freeze solid but will jell up like you said it did.

That is correct. I stored my boat for years in unheated storage in Maine with temps of -20 and lower and never had a problem. It will jell but not freeze. I don't actually know how cold it would have to get to freeze it but it worked fine for me.

[L&M]

Save the environment and maybe someones pet too. Properly drained & filled with pink Rv/No tox you will not have a problem.

[FSNmachine]

Been using Rv antifreeze for the last 5 years and gets as cold or colder here. Never had any problems with it.

[borderline 350]

Dear HB,

The -50 F freezing protection of PURE RV antifreeze is adequate for protection for marine engines, engine oil coolers, etc. BUT THE SYSTEM, must be properly drained of all water and silt as Hank of L & M mentioned. Silt in the exhaust manifold system will prevent complete draining and expose the engine to DILUTED RV antifreeze, which can have problems. Draining & flushing these raw water cooling systems is paramount to the process working.

Note: The newer Volvo/GM V-6 Vortec marine engines have an entrapment area in the intake manifold that must be blown out with compressed air in order to properly drain the manifold!! Knowing how to drain & flush each engine type is important to understand so you do not experience cracked engine components.

I have left samples of the -50 TV antifreeze in the freezer @ -20F ( digital thermometer) and the stuff was the consistency of a weak slurpy. This stuff has a very long slush point before it becomes a solid.

Respectfully submitted,

.............................Jet Boat Bill

[High Bidder]

Thanks for the replies. The reason that I was worried was that I had to replace the heads on the engine last year because the boat was not properly winterized before I bought it. Although the heads were cracked they didn't leak into the cylinders but just a very slow seepage down the outside of the block. I ran it for two years like that until I found the cracks when I pulled the engine to reseal the transom. I didn't want to do again this year.

High Bidder

[MCF]

The second year I owned my inboard/outboard, the mariner owner strongly suggested that I use pink RV anti-freeze and this is in the Buffalo area. Then I got smarter and had him do it every year so I could sleep at night not worrying about what I missed. Then I got real smart and went back to an outboard that can be winterized in 20 minutes.