Bottom Paint and Prop Paint

[DougM]

It's now the end of January which, for those of us in the mid latitudes who are optimists, means that spring is almost here . This time last year, I was considering changing my bottom paint, as well as doing something about fouling on my prop. I got a lot of useful information from this site, and as such, I thought I'd post my experience in case some might find it useful.

As a point of reference, I live in Cape Breton, Nova Scotia and my boat spends most of its time in Sydney Harbour and the Bras d'Or lakes. The boat would normally get used 3 times a week, besides weekend getaways and my once a year week long cruise (Magdalens last year, wish i had more time for these trips!). Our latitude is 46 degrees N, and water temperature is chilly until late July when it warms up to the low 70's, and that's when the fouling accelerates.

My problem was this: I had previously been using a really cheap bottom paint, Atlantic brand by Laurentide Mfg of Quebec, which is a copper-based alkyd. Commercial fishermen use the stuff around here. Anyway, i was finding that I was getting patches of barnacles by the end of August, not a lot but enough to slow me down. Also this paint would soften and wrinkle in spots, and then some of it would come off after haulout. It would take a bundle of work to sand out these areas for repainting in the spring. It dawned on me that my own time was a lot more precious than the money I saved by using this paint so i decided to upgrade.

The other thing that I wanted to address was prop fouling. I would normally clean up my prop shaft and prop, and coat it with a layer of waterproof grease before launch. All would be well until august when a crop of barnacles would grow. As a result, I'd lose a knot of motoring speed, and suffer increased vibration. I'd clean off what i could in the
water, but the damn things would be back by November at which time i wasn't interested in snorkelling

After digesting everything i could read from the sailing forums, i decided to try the following: a) Micron 66 bottom paint; and b) Pettit Zinc Coat barnacle barrier paint on the prop. I stripped most of the old bottom paint off using a fiberglass-safe stripper and then good old fashioned sandpaper (a hateful job!). Then I applied two coats of Micron 66. The prop and shaft were sanded, finishing with 400 grit emery, before spraying on two coats of the Pettit Zinc Coat. See the attached photos of the new bottom paint and prop paint before launch


The boat went in the water at the end of May, and came out late November. I did not clean the bottom or prop during the season. Here's what i saw at haul-out (photos below):

a) the bottom was barnacle free, and the paint was still in good shape, smooth and well adhered to the hull (except where i got too agressive when pressure washing, but i think it was the underlying paint remnants that failed). I was suprised, however, by the heavy layer of slime on the hull, given that Interlux advertises its 'slimicide'. Obviously our local slime wasn't deterred. The slime was easily removed by the pressure washing, though.

b) Although I was skeptical about it when i put it on, the zinc coat dramatically improved my prop fouling issues. As I said, I never cleaned anything on the underside of the boat throughout the season, and I experienced no symptoms of prop fouling. The photo from haulout shows that, other than a layer of slime, the prop was essentially barnacle free, and there were only a few small barnacles on the shaft. In contrast there were loads of barncles on the zinc anode which was not coated. The barnacles also came off with minimal effort. (I really wish i had a photo from the previous year - the difference is dramatic.)

So overall, I'd have to say that i'm very happy with the results I got from both the Micron 66 and the Zinc Coat, and I was able to go through a whole season without any cleaning or noticable loss of performance. I'm going to stick with this combination. This spring, i'll just touch up a handful of spots with sandpaper and apply a light coat of Micron 66. (Next year, I plan to just touch up any required spots, and test their multi-year claims.)

And one final note: A number of years ago, on my previous boat, i used to use a low end ablative Interlux bottom paint. It worked great, but i hated the fact that if you touched the boat when swimming, the stuff was so soft that it would really come off onto your skin. The Micron 66 seems much harder and less messy - I'm guessing this is to do with their 'chemical ablation' that thay claim. Whatever it is, i like it.

anyway, i hope this is of use to somebody.

Bottom paint going on:


Prop Paint


Finished bottom paint


Prop at end of season:


Slime on bottom at end of season:

[fstbttms]

Originally Posted by DougM

The Micron 66 seems much harder and less messy - I'm guessing this is to do with their 'chemical ablation' that thay claim. Whatever it is, i like it.

Micron 66 is a "hybrid" paint. It is technically an ablative but has some hard paint characteristics. It's pretty good stuff.

BTW- fresh water will kill Micron 66. FYI.

[Albro359]

Micron 66 is great...I get more than 2 years out of it in the South Pacific.

I use a New Zealand product called PROPSPEED on prop and shaft - it works really well, but if the boat is left still in the water for a long period (3 months or more) the shellfish will grow on it.....

[Hydra]

Great first post, DougM, very informative. Welcome to CruisersForum.

Alain

[DougM]

I use a New Zealand product called PROPSPEED on prop and shaft - it works really well, but if the boat is left still in the water for a long period (3 months or more) the shellfish will grow on it.....[/QUOTE]


I read lots about propspeed, and it was my second choice. The Zinc Coat won out for attempt #1 because it was about $20 for a spray can, and all i had to do was clean things up and spray on two coats. Propspeed looked to be more expensive and complicated. I'm guessing zinc coat wouldn't fare too well in a long period of non-use either ...