Preventing Marine Grown on Outboard Engine Bracket

A conversation among Whalers
capron
Posts: 1
Joined: Thu Jun 16, 2016 3:34 pm

Preventing Marine Grown on Outboard Engine Bracket

Postby capron » Sat May 22, 2021 7:30 pm

Q1: How is marine growth on outboard engine brackets prevented in warm seawater such as in the Bahamas Islands?

Jefecinco
Posts: 1592
Joined: Fri Oct 09, 2015 6:35 pm
Location: Gulf Shores, AL

Re: Preventing Marine Grown on Outboard Engine Bracket

Postby Jefecinco » Sun May 23, 2021 10:27 am

If a boat is kept in warm seawater for more than three days marine growth can become a problem. The grass, slime and algae can be removed by hand every week or so. The shellfish that attach themselves are a serious problem. For those who trailer a boat and can remove it from the seawater once a week for a good bottom washing probable can do without the expense of applying a barrier coat followed by three coats of anti-fouling paint. Depending on conditions where the boat is moored more frequent cleaning may be required.

When I had a sterndrive propelled boat in relatively cool brackish water moored in a slip the problem was mostly grass and slime rather than barnacles. Most of the growth could be removed by a high speed boat trip of five miles or so. I applied anti-fouling paint which made removing the growth easier. I protected the underwater portion of the sterndrive with an anti-fouling paint made specifically for the purpose. I recall using Interlux Trilux 33 in a spray can which worked well and, I believe, is now available from Amazon and marine outlets Almost every paint then had a very high copper content as that was the active biocide used. Using the high copper content paint on aluminum underwater parts was not recommended.
Butch

jimh
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Location: Michigan, Lower Peninsula
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Re: Preventing Marine Grown on Outboard Engine Bracket

Postby jimh » Sun May 23, 2021 1:51 pm

capron wrote:How is marine growth on outboard engine brackets...


What material is the outboard engine bracket made from?

What is the finish or top coat on the engine bracket?

Outrage 20
Posts: 27
Joined: Mon Mar 08, 2021 11:28 pm
Location: Laguna Hills CA

Re: Preventing Marine Grown on Outboard Engine Bracket

Postby Outrage 20 » Mon May 24, 2021 11:45 am

Put one or two 5-gallon buckets of freshwater on the bow to shift the [static trim of] the boat forward.

PeterO
Posts: 25
Joined: Thu Feb 21, 2019 2:03 pm
Location: Quadra Island, BC, Canada

Re: Preventing Marine Grown on Outboard Engine Bracket

Postby PeterO » Mon May 24, 2021 12:04 pm

I keep my 210 Guardian in the Pacific Northwest in saltwater year-round, and have chronic problems with algal growth and subsequently barnacles on my Lenco trim tabs. What we lack in warm water we make up in nutrients.

I've been advised not to paint the stainless trim tabs, even though the Micron CSC bottom paint I use is recommended for stainless. I tried Aurora VS721 Bottom Coat, which is a wax that purportedly makes the surface too slippery for algal growth, but it seemed to have little effect. A couple of weeks ago I had the boat on the hard, and on the advice of several marine mechanics applied a coat of Diaper Rash Ointment, which is apparently widely used in the commercial industry to protect props and legs. I got small tub of Extra Strength Option+ at the local pharmacy for under $10, which is 40% zinc oxide (a biocide) and 38% petrolatum (a barrier to water). Its too early to assess whether it inhibits growth, but I've cruised a couple hundred nm and it seems to be adhering well.

I'd be interest if others have experience with Diaper Cream or what they use on trim tabs.

Peter O.

macfam
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Joined: Fri Oct 16, 2015 9:24 pm

Re: Preventing Marine Grown on Outboard Engine Bracket

Postby macfam » Fri May 28, 2021 8:16 am

I use Pettit Hydrocoat ECO. A water-based ablative, anti-fouling paint with NO COPPER as a biocide.
Copper and metals underwater can easily cause electrolysis, which in turn will NOT allow the copper availability to protect growth.
You can use zinc spray as a base, and then Hydrocoat ECO.
GREAT RESULTS

Don SSDD
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Joined: Fri Oct 23, 2015 6:58 am
Location: Nova Scotia

Re: Preventing Marine Grown on Outboard Engine Bracket

Postby Don SSDD » Mon Sep 06, 2021 5:54 pm

I thought I’d try the diaper rash high test zinc ointment on my outboard engine mounts that are submerged in the ocean. It prevented growth wherever it was applied and didn’t get removed by water blasting when in motion. I keep my boat on a mooring in the salt water of Mahone Bay and there are small areas where I get a lot of mussel growth on the metal, I had none in those areas. I will continue to use it.

As an aside, our Atlantic Ocean water in Mahone Bay hit as high as 78.6F on my Raymarine. It has been in the high 60’s or low 70’s since mid June. Very warm and good for marine growth.
1986 Outrage 18 with 2001 Honda 130 HP
Former Owner 1991 Guardian 19 with 1994 Evinrude V4 140HP
Former owner 1987 Montauk with 1998 Mercury 90HP
Nova Scotia