what do you use to keep barnacles off prop?
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Petit Zinc Coat Barnacle Barrier .....
so far the best barnacle preventative Ive found. Ive 'tried' all the others at one time or another. Been using it for 2 years. Where before I'd accumulate a huge barnacle ball, now I only get a few teeny 'seed' barnacles. Last season I put several thousand miles on my boat and except for the propeller tips the coating was intact. I also use it on any underwater bronze .... shaft strut, rudder pintels, etc.; better than bottom paint for bronze. www.defender.com/product.jsp?path=-1|10918|296162|11453|311507&id=157662
so far the best barnacle preventative Ive found. Ive 'tried' all the others at one time or another. Been using it for 2 years. Where before I'd accumulate a huge barnacle ball, now I only get a few teeny 'seed' barnacles. Last season I put several thousand miles on my boat and except for the propeller tips the coating was intact. I also use it on any underwater bronze .... shaft strut, rudder pintels, etc.; better than bottom paint for bronze. www.defender.com/product.jsp?path=-1|10918|296162|11453|311507&id=157662
Prop treatments
When I kept up with the Catalina 320 Int'l Assoc. mail-list in the early 2000's, someone published a rather elaborate treatment regime that they claimed worked well. I can't find it now, but I remember that it would have been expensive to buy the several products. One of the products was "Prime-Wash". I found this recently, from the web page http://www.propscanusa.com/propeller_checklist.htm *************** Painting your propellers will degrade the performance. Barnacles, on the other hand will degrade the performance more than properly applied paint. If you use the boat often painting is not necessary. If you have the bottom regularly cleaned then painting is also not required. On the other hand, if you are like most of us and use the boat not as often as you would like, then painting may be helpful. Follow the procedure below when painting propellers: A. The propellers will be clean when you receive them apart from a light coat of oil. Remove this oil film using alcohol or acetone. B. Choose a good quality Zinc Chromate primer and lightly coat the propellers. C. The anti-fouling paint to use on the propellers is sold under various trade names as ‘Outdrive Anti-fouling Paint’ in spray cans. Spray 2-3 light even coats of paint on the propellers taking care not to get any paint into the bore of the hub. D. Allow at least 48 hours drying time before putting the propellers into service. E. Dont apply standard anti foul paint with a brush as it tends to "spin off" the propellers quickly and can not be applied as evenly as spray paint. ************* (I've approached several pros about such treatments and they usually say "forget it. It's a lost cause.") Gary B. Even Keel II
When I kept up with the Catalina 320 Int'l Assoc. mail-list in the early 2000's, someone published a rather elaborate treatment regime that they claimed worked well. I can't find it now, but I remember that it would have been expensive to buy the several products. One of the products was "Prime-Wash". I found this recently, from the web page http://www.propscanusa.com/propeller_checklist.htm *************** Painting your propellers will degrade the performance. Barnacles, on the other hand will degrade the performance more than properly applied paint. If you use the boat often painting is not necessary. If you have the bottom regularly cleaned then painting is also not required. On the other hand, if you are like most of us and use the boat not as often as you would like, then painting may be helpful. Follow the procedure below when painting propellers: A. The propellers will be clean when you receive them apart from a light coat of oil. Remove this oil film using alcohol or acetone. B. Choose a good quality Zinc Chromate primer and lightly coat the propellers. C. The anti-fouling paint to use on the propellers is sold under various trade names as ‘Outdrive Anti-fouling Paint’ in spray cans. Spray 2-3 light even coats of paint on the propellers taking care not to get any paint into the bore of the hub. D. Allow at least 48 hours drying time before putting the propellers into service. E. Dont apply standard anti foul paint with a brush as it tends to "spin off" the propellers quickly and can not be applied as evenly as spray paint. ************* (I've approached several pros about such treatments and they usually say "forget it. It's a lost cause.") Gary B. Even Keel II
Desitin
I heard Desitin works great but I have never tried it. It is a baby ointment used for treating and preventing diaper rash. I believe it contains zinc which is probably the active agent here. Its worth googling. Rob
I heard Desitin works great but I have never tried it. It is a baby ointment used for treating and preventing diaper rash. I believe it contains zinc which is probably the active agent here. Its worth googling. Rob
A little off-topic, but some cruisers
use Desitin on the bottom of the dink to retard growth; if you can buy it by the drum at costco...
use Desitin on the bottom of the dink to retard growth; if you can buy it by the drum at costco...
Desitin works OK but quickly erodes away ...
... when the prop is spinning. To get the longest life out of the Desitin is to apply in thin coats and let dry thoroughly before you launch the boat. It 'may' last 1-2 months at best. Another 'trick' is to get oxytetracycline from a Veterinarian, crush and very finely pulverize the pills/powder and add this to bottom paint applied to the bronze. It will eventually leach out of the paint and leave teeny 'craters' but will last a few months. Not a good thing to do with the environment as you are contributing to the 'anti-biotic resistance' of many organisms. Another way to prevent barnacles is to NOT put a zinc on your prop/shaft, use a calibrated EMF cell, and hang a precisely cut surface area zinc (guppy) over the side of the boat that is electrically connected to the bonding system (including the prop and shaft). You adjust the amount of zinc so that the electrical potential is just a very few millivolts. Barnacles wont attach if there is a very slight electrical potential. But you need to check the EMF from the 'guppy' very often to keep the prop. 'protectied'. Too much bother and requires constant monitoring. BTW if the underwater gear is 'overprotected' by too much zinc, barnacles seem to like to attach there.
... when the prop is spinning. To get the longest life out of the Desitin is to apply in thin coats and let dry thoroughly before you launch the boat. It 'may' last 1-2 months at best. Another 'trick' is to get oxytetracycline from a Veterinarian, crush and very finely pulverize the pills/powder and add this to bottom paint applied to the bronze. It will eventually leach out of the paint and leave teeny 'craters' but will last a few months. Not a good thing to do with the environment as you are contributing to the 'anti-biotic resistance' of many organisms. Another way to prevent barnacles is to NOT put a zinc on your prop/shaft, use a calibrated EMF cell, and hang a precisely cut surface area zinc (guppy) over the side of the boat that is electrically connected to the bonding system (including the prop and shaft). You adjust the amount of zinc so that the electrical potential is just a very few millivolts. Barnacles wont attach if there is a very slight electrical potential. But you need to check the EMF from the 'guppy' very often to keep the prop. 'protectied'. Too much bother and requires constant monitoring. BTW if the underwater gear is 'overprotected' by too much zinc, barnacles seem to like to attach there.
I also sail the Chesapeake bay but I dock the boat in fresh water
In 8-9 years I haven't seen any barnicles on the boats up here. In past days sea captains would take their ships up river into fresh water for a couple of day to kill the barnicles and other salt water loving hard growth.
In 8-9 years I haven't seen any barnicles on the boats up here. In past days sea captains would take their ships up river into fresh water for a couple of day to kill the barnicles and other salt water loving hard growth.
I use ordinary old zinc oxide
ointment on my knotmeter impeller. Zinc oxide is basically the same thing as Desitin, only a lot cheaper generic version of it. I typically go until August on the mid-Chesapeake until my impeller needs cleaning. I do not think zinc oxide would last very long at all on a prop/shaft due to much higher rpms. For the past few years I have been sanding my bronze prop and shaft down to bright metal with wet/dry fine emory paper. Then I apply a couple of coats of spray Interlux Primocon primer. Slap on two more coats of whatever modified hard epoxy bottom paint I have on hand. At the end of an 8-month season here, most of the paint is just about gone and I have a few small barnacles on the prop. I don't think I can do much better than this.
ointment on my knotmeter impeller. Zinc oxide is basically the same thing as Desitin, only a lot cheaper generic version of it. I typically go until August on the mid-Chesapeake until my impeller needs cleaning. I do not think zinc oxide would last very long at all on a prop/shaft due to much higher rpms. For the past few years I have been sanding my bronze prop and shaft down to bright metal with wet/dry fine emory paper. Then I apply a couple of coats of spray Interlux Primocon primer. Slap on two more coats of whatever modified hard epoxy bottom paint I have on hand. At the end of an 8-month season here, most of the paint is just about gone and I have a few small barnacles on the prop. I don't think I can do much better than this.
Cold Galvanizing
I use Rust-Oleum cold Galvanizing. You can get it at any hardware store for about $6 a can its a paint with 97% zinc that will wear out in about 3 months if I put three coats (after that a mask/snorkel and a scraper). I use it for the prop, shaft and strut. Not perfect but works for me. I guess is the similar to the Petit Zinc coat barrier.
I use Rust-Oleum cold Galvanizing. You can get it at any hardware store for about $6 a can its a paint with 97% zinc that will wear out in about 3 months if I put three coats (after that a mask/snorkel and a scraper). I use it for the prop, shaft and strut. Not perfect but works for me. I guess is the similar to the Petit Zinc coat barrier.
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