Propspeed Foulfree transducer protection, first impressions

When Ben Stein wrote about the new Foulfree transducer “paint” last November, I wondered how much coverage came out of that little $35 tube. I can answer that question now. In the scene above, I’m about to apply Foulfree to six transducers — the two loose and four already fixed to Gizmo’s bottom — and to my amazement, I only used about a third of the tube. So if the stuff really works, the one kit will protect a ducer-intensive boat for three seasons (though I’ll have to supply my own brush and surface prep tools next time).

I also found the process easy, as the silicone polymer seems enthusiastic about flowing into the recommended thin coat and I wasn’t worried about toxic substances. Of course, I won’t know how well it works for at least several months (and maybe a DIY hookah dive), but I’m sure hoping for better performance than what I’ve experienced from that old bottle of MDR transducer paint (that’s still kicking around my bottom maintenance locker).

I’m also hoping that the Foulfree will do better than the water-based and copper-free Pettit Hydrocoat Eco I’ve often used, and I’m already comforted by Airmar’s endorsement that Foulfree won’t negatively affect sonar performance. But I was happy to again apply some remaining Hydrocoat Eco over the inexpensive and easy-to-apply Pettit Prop Coat Barnacle Barrier I’ve long used to protect Gizmo’s bronze prop and stainless rudder. (I’ve learned over the years, though, that anti-fouling effectiveness has to do with a boat’s shape, how it’s used, and the microclimate of its home harbor as well as the coatings used; so results may differ.)



Finally, this was the first time I worked on Gizmo’s bottom in a windowless shed with a concrete floor, and I came to deeply appreciate the two accessories shown above. That Craftsman 9000-Lumen LED Work Light had already brightly lit the boat’s interior for many project sessions before illuminating bottom and topside details to a degree I hope few will notice now that Gizmo is at her mooring (my work is not up to what Wayfarer Cove did in 2018).

Then there’s that $11 Harbor Freight dolly with a large chunk of borrowed boat blocking on top. It was perfect for scuttling around the boat’s less accessible bottom areas, and your knees, back and shoulders may be equally grateful.

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

6 Responses

  1. Xavier says:

    We use a can of Penaten Cream (18% Zinc Oxide) diaper rash ointment we bought for $6.50 in 2014. More than 3/4ths of the cream is still in the can.

    Keeps the transducers clean for about 6 months.

    https://drugsdetails.com/penaten-cream/

    • Ben Ellison Ben Ellison says:

      Purportedly also good for taking the itch out of fresh sailor tattoos and many other uses! Zinc Oxide sunblock creams don’t seem have the same high percentage, but it also seems possible to blend your own coating: (maybe with waterproof grease?):

      https://www.makeyourown.buzz/zinc-oxide/

      Then again, that Pettit Prop Coat I use — which “contains highest amount of pure Zinc” — is not recommended for transducers:

      https://pettitpaint.com/media/4449/prop-coat-barnacle-barrier-product-data-sheet.pdf

      • Xavier says:

        Well, I have this plastic N2K speed/depth/temp DST800 transducer. I am on the third one since early 2013. I am pretty sure the original one failed before I started applying Penaten in late 2014, and it got replaced under warranty.

        The second one failed in 2017.

        On the third one, the temp sensor was the 1st thing to fail, as these always do so far. Temp failed in late 2018. I wonder how much longer does it have before it goes.

        The other transducer is much larger, a ForwardScan. Installed in 2015, it hasn’t yet failed, despite the use of zinc oxide.

  2. I’d love some advice on VALENCIA’S need for increased dependability/new transducer. 1958 Olin Stephens sloop. Can I employ the current transducer and wire it to new depth meter? Is it important to have all new gear including the actual transducer embedded in the keel? Basic ignorance, here. Thanks, Doug Day

    • Ben Ellison Ben Ellison says:

      Hi Doug. Doubt you can use old transducer but no one can advice you without specifics about what it is and what it originally attached to. Plus they do wear out. But then again new transducers sometimes fit in the same casing as old one, or at least same casing hole. So what’s there now?

  3. Ben Ellison Ben Ellison says:

    Update on Foulfree Transducer protection: Gimo sat out the 2021 season, but last spring I had plenty of remaining Foulfree to coat her four active thru-hull transducers — two Airmar DSTs, a Simrad StructureScan HD, and a Furuno 520-PLD — plus the large Humminbird SOLIX MEGA SI+, DI+, CHIRP unit hung on the transom of Junior. Propspeed’s claim that “One 15ml kit will coat 1 square foot” of transducers is no exaggeration.

    All transducers stayed quite clean living from early June until late October in Camden Inner Harbor’s challenging salt with freshwater overlay microclimate, plus some cruising and regular lobster trap hauling. That was particularly impressive on Junior as that ducer gets a lot of fouling-friendly sunlight. So while there’s still some Foulfree in that little tube, I’ll get a new kit next spring.

    Also, Propspeed introduced Stripspeed at METS and while I don’t have any experience with the company’s main running gear protection product (and namesake), this sure looks like it will make application easier:

    https://propspeed.com/products/stripspeed/product-information

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