The ultimate propeller anti-fouling paint

Discussion in 'Materials' started by CDK, Jul 28, 2012.

  1. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    Before putting my boat back to sea this spring, I've done a little experiment.
    Removed the completely overgrown bronze props, cleaned them with hydrochloric acid and polished them with 200 and 400 grit.
    Then, instead of wasting more money on anti-fouling that doesn't work, I gave them a single coat of 1:1 clear polyurethane lacquer formulated for wooden floors. The brand was Chromoden 2K but I think every paint manufacturer has such a product. It is cheap, somewhat flexible and has a high resistance to wear because it was meant to walk on.
    Now, after a little over 3 months in the sea, the props are as clean as the day I painted them and the coating is without flaws. The stainless rudders next to the props, painted with hard matrix anti-fouling are already covered with a variety of sea life, most of them hard as stone.

    I know that 3 months is not enough for an appraisal, but it looks very, very promising!
     
  2. rubenova
    Joined: Aug 2011
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    Location: Fidalgo Island, WA

    rubenova Junior Member

    This is an exciting result! Thank you for thinking "out of the box." I was raised around real life "McGiver's" that got things done with what they had at hand. Re-purposing things at hand to do things never intended is (in my opinion) the hight of human spirit. Please keep us updated on you progress.
    cheers
     
  3. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    Update

    Due to unexpected personal circumstances the boat stayed at its mooring during the past 8 weeks.
    Yesterday I took the boat to a sandy beach and inspected the props. The first impression was rather disappointing, but most of the growth could easily be removed with a Scotch-brite sponge. What remained are some small white barnacles that succeeded in attaching to the still slippery polyurethane.
    This probably would not have happened had the boat been used regularly.

    My conclusion is that the parquet lacquer performs at least as good or even better than much more expensive anti fouling products.
     
  4. Tynesider
    Joined: Aug 2012
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    Location: Telford Shropshire

    Tynesider Junior Member

    Hi CDK

    I know water conditions vary around the world, infact they even vary around the UK coastline, but I have had good success by just simply covering my prop in grease!

    Yes it comes off in time (engine 2200rpm max) but it does seem to leave a thin coating of grease on the prop! :)

    Mike

    Pic 1 at lift out after 2 years 'in', Pic2 before launch, Pic3 after jet wash 2 years later
     

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  5. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    Looking at the dark color in Pic 1 I guess you mainly have plant life on the hull, probably due to low water temperature.
    Here we have 28 C. (82 F.) during the summer months, salinity 3.8% and a limestone seabed. Marine growth is mainly barnacles and shellfish like clams and oysters, but it invariably starts with some small creature that builds thin calcium tubes crisscrossing all surfaces underwater. Larger animals use these irregular structures as a base.

    I have a fiberglass rowboat without anti fouling; its bottom is completely covered with clams and oysters as large as my hands. Unfortunately the clams have large shells but the animals are too small to eat.
     
  6. Tynesider
    Joined: Aug 2012
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    Location: Telford Shropshire

    Tynesider Junior Member

    Hi CDK- Low Water Tempreture :D

    Yep you are right, you do not want to 'fall in' here, 'today' the sea surface tempreture is 14c (57.2f). Infact if you 'fall in' during the winter it's 99.9% going to be a recovery job, not a rescue job, as survival time is measured in minutes!

    If we had 28 deg C I would be on cloud 9, second thoughts no I won't I would be swimming in it :)

    Mike
     
  7. lewisboats
    Joined: Oct 2002
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    Location: Iowa

    lewisboats Obsessed Member

    I wonder if anyone has tried PTFE (teflon)
     
  8. Tynesider
    Joined: Aug 2012
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    Location: Telford Shropshire

    Tynesider Junior Member

  9. Milehog
    Joined: Aug 2006
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    Location: NW

    Milehog Clever Quip

    The grease treatment works here in the cool waters of the Salish Sea. 11 degrees C today.
     
  10. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    Yes I did. I bought 4 ridiculously expensive spray cans, marketed as Volvo Penta Teflon prop anti fouling. A light grey special primer and a dark grey, almost black finish. Followed the exact instructions, put the boat back in the water and watched how just a few weeks later the dark skin started to come off and sea creatures took possession of the primer surface that proved to be excellent holding ground.

    Virtually nothing adheres to Teflon, which implies that Teflon also does not adhere to anything. It took the frying pan companies many years to develop the process for their coatings and on most cheap Asian products the quality is still lousy.
     
  11. Chuck Losness
    Joined: Apr 2008
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    Location: Central CA

    Chuck Losness Senior Member

    I used Pettit zinc coat anti-fouling on my prop and shaft on my last haul out and was pleased with the result. Not prefect but had less growth both barnacles and algae than in the past and what growth I had came off very easily. I will put on another coat this year. Water temps in the Sea of Cortez are generally warm and range from mid 60's F in the winter to mid 80's F in the summer.
     
  12. L'eau.Life
    Joined: Jan 2008
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    Location: Bay of Islands, New Zealand

    L'eau.Life Junior Member

    We use a product called PROPSPEED which seems to be a silicon base. Expensive but effiective and my last application lasted 3 years on the marina. I know a guy who uses a CRC spray-on product called Soft Seal which he claims works for a year or so and I happened to be next to him on the hard when he hauled and his prop and running gear were clean.
    I just had all my running gear re-"prop speeded" ($$$ OUCH!) and the hulls re-antifouled so I hope that is it for a few more seasons!
     
  13. Landlubber
    Joined: Jun 2007
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    Location: Brisbane

    Landlubber Senior Member

    Yeah, Prop Speed is what we use here too, seems the best available that I am aware of currently.
    I have used it for many years now and am very happy with it.
     
  14. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    update

    The boat was in the water until end November last year.
    The parquet lacquer did not prevent all growth (see port prop), but I cleaned the starboard prop in a few minutes, with lukewarm water and a dash of hydrochloric acid, using nothing but a household sponge. The lacquer seems undamaged but lost its gloss, so I will apply a new coat without removing the props.

    The picture of the hull shows a lot more marine growth, despite the overly expensive "hard matrix" antifouling. From the dark spot I removed a large oyster!
    I have not yet decided how to treat the hull. Probably the best course of action would be to remove all the old paint, but the job isn't very appealing.
     

    Attached Files:


  15. michael pierzga
    Joined: Dec 2008
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    Location: spain

    michael pierzga Senior Member

    Years ago I used to prep yachts for the Dusseldorf boat show. I would polish the propellors to glow like jewelry, then coat them with two part clear so fingerprints wouldn't tarnish the jewlerly. Those props would stay bright and attract minimum growth on well used boats for a complete antifoul cycle.

    I no longer have the patience............
     
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