Antifouling a Prop

[fstbttms]

Originally Posted by Cavaletti

Any Ideas?

Yes. God invented hull divers for a reason. Just sayin'.

[cvondo]

I just completed a 2 month study using some of the ideas from this forum for prop antifoulant. I used a metal paint roller pan as my substaight. I coated it front and back with 6 diffent substances . It was placed in the in the lagoon in cocoa beach fl. 2 diffent Brands of black perminant marker was used with 4 coats. After 2 months there was significant barnicle growth on both brands. Next pink magic marker was used and there was mild growth on it. It was significantly less than the black . Next was silicone clear silicone west marine calk. It had good adherance to the pan and had very little growth and what was there easy was removed. I then used the silicone mixed with a few other substances but there was poor adhesion and some was peeling off the pan. The 100% silicone clear will be tried as well as the pink marker when I pull the cat. I think some of the e pensive prop anticoulants contain high content of silicone which maybe the true active ingrediAnt vs some of the other additives. I have pictures of the study and will try to post them later if I can figure out how. This proved to be very nteresting and I will try it again with egg white and some of the copper based products. Thanks chris

[anglooff]

Dear Chris,

Keep us updated...Its a subject I often ponder.

Regards

Alan

[Wotname]

Its time for an update on the performace of my copper plated prop.

The boat was slipped yesterday after 10 months in the Swan river and the prop had done about 25 hours.

There was significant barnacle growth on the unplated exposed shaft and there was one large barnacle on the centre of one blade with some very small barnacles on the tip of another blade. There only other barnacle growth was on some untreated bolt heads nearby and at the bottom of the keel where the antifouling has been abraded.

So I suggest the copper plating does work to some extent. It has certainly been better than anything else I have tried.

As to the future performace, well I am not sure how much copper is still on the blades but I will be able to report again next year

[ribbony]

We solved the fouling problem, there has been no growth at all on the prop this last 5 months.

It has been sitting on the floor of our garage




Yeah, it made more sense to dive under and remove it over the winter. I can polish it up and use some hot lanolin grease. This summer we plan to tie a heavy garbage bag over the prop whenever we leave it for any length of time. We did that a few times last summer and it made a big difference. i give the blades a light scrape before putting the bag on to remove any tiny barnacles that may have tried to setup residence there.

[S/V Illusion]

let us know if barnacles like garbage bags - maybe a test to see if they prefer black, pink, magic marker treated, silicone treated, etc...

[ribbony]

The colour preference will probably depend on the sex of the barnacle





Though I have noticed that they do not in general seem to like residing on plastic bags, probably as it moves constantly in the tidal flow and currents. We get some slime and other accumulations on the black plastic, but not barnacles. Perhaps that answers you question in part, they do not like black ?

[Randal Johnson]

I ordered Hawkspeed from Fisherie's Supply and just received an email saying it had been taken off the market. Another supplier told me it was taken off the market because of poor adhesion.

[fstbttms]

This prop was coated with Hawkspeed and then motored approximately a mile to the boat's slip. Here's what was left. I kid you not.

[ribbony]

Ouch !!!!

What did that nice yellow coating cost to apply ?

[fstbttms]

Originally Posted by ribbony

Ouch !!!!

What did that nice yellow coating cost to apply ?

No idea. Except I know it wasn't cheap.

[impi]

Guys, I had my prop antifouled with INTERNATIONAL Trilux prop-o-drev product. It advertises antifouling for drives and propeller.
The boat was slipped back into the water and I took her about 1 mile back to her birth where she lay for about two weeks. I then started up the motors and noticed a slight vibration. I stopped the engines and sent a diver down. The propeller coating looked all flaked, was delaminating and had a powdery chemical reaction (aluminium props). Also the rubber in the prop between the prop and hub was gone.

Any ideas?

[ribbony]

Double Ouch !!!

Sounds like electrolysis. Was any welding done to the boat on the water or was any welding done to an adjacent vessel berthed nearby ? If it happened to your vessel it might have also happened to others.

Is your vessel GRP or metal ?

[osirissail]

Originally Posted by impi

. . Also the rubber in the prop between the prop and hub was gone.
Any ideas?

I assume these are outdrive or outboard props since they are aluminum alloy and have a rubber shear clutch between the propeller and hub.
- - Did the antifoulant application process include "heating" the propeller? Some of the "long life" prop antifoulant require heating to evenly disperse the coating. If the coating process requires heat then an outdrive/outboard propeller with a rubber shear clutch is an absolute "no-no" as the bond between the rubber and blade hub breaks free.

[impi]

Originally Posted by ribbony

Double Ouch !!!

Sounds like electrolysis. Was any welding done to the boat on the water or was any welding done to an adjacent vessel berthed nearby ? If it happened to your vessel it might have also happened to others.

Is your vessel GRP or metal ?

Well I'll be dammed. Yes, infact the boat next door had welding activity for two days - fitting stainless rails etc. Etc.
Is there anything that could be done when welding that would stop this?
Vessel is fiber glass... Should there be anything else I should look at?
Thanks for the info