Antifreeze To Winterize Your Classic Boat! Pink Or Green? Blue? Purple?

In yesterdays story a subject came up, and as story ideas start drying up, we thought, hey, that’s a great idea for a day of comment banter. The topic is, Do you use the Pink RV stuff sold at West Marine, or the normal Green stuff at your auto parts store?

West Marine Purple and Blue. I will add if you need a -100 Antifreeze, you are a master at this.

Now, I have always been told to use the pink RV stuff that is more kind to nature. Since the antifreeze winds up on the ground as it washes out. Not to mention, but I am right here, has corrosion inhibitors.  But some say no way, use the green stuff. Okay, maybe its better and works in colder areas? But that stuff is some rough stuff on mother nature. So? What is the way to go? Does it matter, do you fill a 5 gallon bucket under the exhaust and the green is better? Do we just put food coloring in some warm water? What about that windshield washer stuff? Its Blue? Maybe warm coffee. Wow, okay, I am doing this story way to early in the morning. I am on a 7AM plane to California. By the way, there is no more math in the comment section. So have fun while I am in the air!

24 replies
  1. Rick
    Rick says:

    I’ve always used the pink drink here in lower NY with no issues. The yard that I keep my fiberglass cruiser at does the same.

  2. Greg Lewandowski
    Greg Lewandowski says:

    Always used the good old Prestone green. Two to three gallons depending on the size of the engine.

  3. Troy in ANE
    Troy in ANE says:

    For decades my Dad simply drained the block on the MCL in Yorktown, and other boats, it always worked well. The only trouble with this method is corrosion protection.

    When I started caring for the boats I started using the pink RV antifreeze. It works, but I have had it “Slush” before and there also are no corrosion inhibitors, so now I buy the West Marine purple stuff. Good to 60 below with corrosion inhibitors. It goes on sale for $4.99 or $5.99 a gallon in September or October and it is supposed to be environmentally friendly. I still like to drain the block before I introduce the anti-freeze. Some say I am making more work for myself, but I like to take the extra step to ensure that the anti-freeze does not get diluted.

    Here is one for you. Some yards around here use Vodka with food coloring in the domestic water system because the owners don’t want the pink stuff in their water lines.

  4. m-fine
    m-fine says:

    The bigger trouble with just draining is sometimes the water doesn’t all come out. I have seen blocks that were drained crack open because silt or debris held a pocket of water. I think the Q series manifolds can meet an early death from retained water as well. So, I drain, refill with pink stuff, run to circulate and then drain again.

    The purpose of the pink stuff is burst protection and light corrosion inhibition. That is exactly why we use it. It is not designed for long term use in a running engine where the primary purpose is heat exchange so it is different from the automotive products.

    • jim g
      jim g says:

      The Q series intake manifolds had a sticker next to the big pipe plug behind the carb that said “When winterizing remove plug and fill with anti freeze”

  5. m-fine
    m-fine says:

    One more thing. The temp that the stuff (any kind) turns slushy is still well above where it will create enough pressure to burst pipes or blocks.

  6. Mark
    Mark says:

    I use the blue stuff on Rocket Man. I didn’t think the pink went down far enough in temperature and did not have any corrosion inhibitors.

    I did not know about the purple stuff. I may switch to that next year.

    Amazing how fast it pumps into the engine. Don’t have to run for very long at all.

  7. Troy in ANE
    Troy in ANE says:

    I also use “fogging” / “storage oil” in all my engines. I feel that CRC brand makes the best fogging oil.

  8. Bill DeGlopper
    Bill DeGlopper says:

    I use the pink West Marine on my 2 vintage jersey speed skifff race boats. First drain the block, then remove the lines & blow out with a compressor air gun. Never any issues with the Chevy 350 engines . Boats are stored indoors at Anchor Marine in an unheated building.

  9. Sean
    Sean says:

    I use whatever my marine tech at the marina chooses. Done professionally, if there’s a problem they look after it. BTW: I have a “modern” repower so obsolescent parts (block) are not an issue if I needed one. I don’t need to sweat the small stuff.

  10. Andy
    Andy says:

    Sean has the best advise. Have a dealer do it and then if there is a problem they are responsible to fix it. On the colored antifreeze. Actually the pink is water system anti freeze they use in RV’s and cruisers. It is supposed to be good to 50 Below. The blue 100 below is what is meant from the engines. Both are king to nature

  11. john
    john says:

    how about closed cooling conversions for the old flat head 6’s

    what’s the consensus? has anyone seen this done to an ace or a crown motor?

    • Troy in ANE
      Troy in ANE says:

      I have heard about it on Hercs. Have designed a system for my W’s but have not yet gone through the steps to build and install it.

  12. Jack
    Jack says:

    In Georgia we drink the vodka. We call that a Martini.
    Regarding the antifreeze we use the pink and just drain the block then refill it. That way if we have a nice December day we can go out easily for another last grasp.

  13. Troy in ANE
    Troy in ANE says:

    There was a tech here in the ANE that would drink the Vodka when he commissioned the boats in the spring. He got fired.

  14. Briant
    Briant says:

    I guess we are lucky out here on the West Coast. I don’t use any of the above products. Our boat rests in a nice garage that never gets below freezing. Once a month all winter long, i wait for a nice day and I take Zoomer down to the local ramp, put her butt in the water, fire up the power, and let her idle for 20 minutes. Ok, ok, I do also rev her up. I also engage the prop to keep everything moving and active. With a fuel stabilizer in the tank, come springtime….getting back onto the water is easy peazy. As with our classic car, mechanical toys suffer from lack of use.

  15. Herb Hall
    Herb Hall says:

    We may be on the west coast, but at Tahoe, we get freezing temperatures, so proper winterization is a must. We store about 400 boats each winter, so we have some very proven methods. Troy mentioned CRC fogging oil and this is the first step in the winterization. Spray it in the the carburetor until you get a lot of smoke from the exhaust. This will keep corrosion from forming on the valves a n cylinder walls. Also we put in fuel stablilizer. As for antifreeze, we use the pink stuff, but mostly in hard to drain areas like coolers. We drain everything else. Draining allows sediment to get flushed out of the block. If you just antifreeze each year, sediment will build up in the block over time.

  16. WoodyGal
    WoodyGal says:

    First we change the oil, Dello 15-40 & filter. Then we pull the pink stuff into the running engine from a five gallon bucket, about 3 gallons, until exhausts are putting out pink stuff, then fog it. Done!

  17. John Rothert
    John Rothert says:

    I like the woodygal solution…..
    I just checked in to see what solution the solution was in…..

    John in Va.

  18. Dennis
    Dennis says:

    Ok -I was told that we should not drain the anti-freeze after running it through. Some on this thread indicate that they drain after running. So what is right?

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