Copper plated props?

Before:


After:


With this:


We'll see how it works.

Anyone know what the difference between cold galvanizing spray (zinc) and Barnacle Blocker or Barnacle Barrier is? I figure about $25 after I compared MSDS's, but I'm not really sure...

I think you are correct...tried Petit this time..if it works..will try just plain cold galvanizing in the spring...

I used Rust Oleum cold galvanizing spray last time I launched. But quite honestly, previous experience would dictate that it would only have to block a single barnacle (well, OK, maybe 2 or 3) to be a success where I boat. My bottom or prop just doesn't get that fouled.

QB said:

We'll see how it works.

Click to expand...

To follow up, the answer is: not very well. After 4 months in the water and about 30 hours of running:



I don't know what the yard did for prep, but adhesion is poor. We're taking it back down to bronze.

We're there barnacles on all those spots?

manyboats said:

We're there barnacles on all those spots?

Click to expand...

No, seemed to be all just paint blistering.

I put zinc diaper cream on mine. .

Jim

JDCAVE said:

I put zinc diaper cream on mine. .

Jim

Click to expand...

On your what ?

...prop! Seriously. I did that. My shipwright suggested it. I have since noticed a lot of commercial fishermen do that in my marina. It's also mentioned on several forums.

http://www.practical-sailor.com/blog/-10907-1.html

Jim

Both my props looked like the struts, with some previous coating flaking off. Stripped, sanded, and painted with Rust Oleum zinc cold galvanizing. I'll see how she looks in October at haul out.

boatpoker said:

On your what ?

Click to expand...

:lol::lol:

Zing!

Okay! Okay! Okay!

;-)

over the years, I have tried bottom paint on my props with inconclusive results. 2 years ago I painted one lobe on each prop and could see no difference in teh amount of barnacle growth when compared to the unpainted lobes. So last year, on April 14, I hauled and chose to leave the props unpainted. By the end of June, i had so much barnacle growth that it overloaded boat engines. When i got to warmer water, I manually removed the barnacles, while in the water. By April again, the growth is so thick that the engines are blowing black smoke and won't get up to full speed.
I attribute this dramatic change from other years to a change of location. from April to October, my boat is now moored at Saltspring Island, from October to April, in Vancouver's Coal Harbour. The salinity of the water and its health for barnacles is dramatically different, so a different regime is called for. I haul again on June 1, so this time I will be painting the props.

i had so much barnacle growth that it overloaded boat engines

MR Herrishoff used to explain that you should envision the prop and growth blown up to the size of the boat !

That makes it easier to understand what growth does to the performance.

My thought is, if this would work, someone (probably a prop manufacturer) would have figured this out many years ago and incorporated it into their products.

In the PNW, the most common barnacle is Balanus glandula. This species is the one most commonly responsible for propeller fouling. Understanding the life history of this animal might be helpful in adjusting your cleaning schedule. Barnacles are crustaceans, with 2 motile stages: naupli, and cypris stages. Near the end the cypris stage, they settle. The naupli and cypris stages are timed to the high productivity in the northern parts of the Pacific in March. Settlement takes place in the spring, for the most part.

This is a useful treatise on the subject...

http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/8711/v10n4-415-422.pdf?sequence=1

So, in the PNW, at least, it's best to focus your cleaning of the propeller during and after spring. Colonization of the propeller will be at its maximum during April to June. There is some barnacle settlement during the summer months as well.

My boat sits in the freshwater for the most part in April and May, so I am less affected.

Jim

...note Figure 1 page 417 in the linked document above. Note particularly the lower curve, which shows those individuals newly settled. The curve that show larger individuals in April represent the cohort that settled in the previous spring. Growth is rapid during spring and summer months and individuals who remain immersed have twice the growth rate of those who are exposed at lower tides.