Dave Stump has suggested stove polish for keeping barnacles off the prop. Here is another system. I was hoping to make some money off of a patent, but that is not going to work out so here it is. Remember, you heard it here first.
For the past six years or so I have been developing a system to keep barnacles off the prop of my CD36. For the past 3 years my propeller blades have been free of barnacles. In our marina this past year has been a real test. Many boats had to be pulled mid season to have both the bottoms and propellers scraped. A boat that is two slips away from me had to be pulled twice for propeller cleaning. Each time the prop was engulfed in barnacles. My prop remained clean except for a small number on the hub. I have pictures, but no web site to post them on.
First, a little background. Copper does not kill barnacles. Copper oxide kills the little ones. We place zinc on our prop shafts to galvanically protect the shaft and prop. unfortunately this protection keeps the prop from oxidizing and the barnacles have a nice home. The barnacles grow big and the drag on the prop keeps it from performing very well. Sometimes this results in black smoke. Leaving the zinc off will allow for the copper oxide, however the zinc will preferentially leave the prop and the prop will weaken. How can we protect the prop and shaft and still allow for a layer of copper oxide? Adding copper will not work because it is protected by the zinc. Anti-fouling paint does not seem to work because it either wears off too quickly or because the copper oxide is converted back. Desitin has not worked for people in our marina either. The answer is simple. Put a layer of insulation on the prop and then add a layer of copper. The outer layer oxidizes while the prop and shaft can be protected by their zinc.
My implementation of this has been to clean the prop with phosphoric acid (naval jelley has this in it) and coat with two to three layers of West system epoxy mixed with some form of colorant. I lightly sand between layers for a nice smooth job. Be careful to get enough of a coat on the sharp edges. I then use two coats of west epoxy with their copper compound. When the last coat is still tacky I dust with the copper compound. Try not to loose any of the copper compound up your nose. One trick is to make certain that the job is clean and there is no foreign matter in the epoxy. If a chunk of dirt or a spec of sawdust is in the surface the barnacle can get a strart on life there. Once it has a foothold it can grow to maturity.
Last year I did not get a good preparation of the bare prop and the coating started to flake off at the end of the season so do a good job with the acid.
Other formulations might just involve painting the prop with some other paint to act as an isulator. There are a number of other variations which might work. If the stove polish thing works consistently, then that would probably be much easier.
Enjoy barnacle free motoring....
Matt
mcawthor@bellatlantic.net
Propeller Barnacles....Another solution
Moderator: Jim Walsh
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D. Stump, Hanalei
Re: Sounds good, but...
Matt,
Sounds like a good idea in theory, but your last comment about time is right on. It only takes about 2 minutes, after cleaning it with On&Off, to put on a coat of the stove polish and, this year at least, when Hanalei was pulled there were NO barnacles on the prop! She had been in since April 1st. and was pulled the 15th. of November. The sailboat in the slip right next to mine had a significant number on it's prop when pulled, but not as bad as what you describe happened in your marina. Maybe it has something to do with geographical location, I don't know.
I still don't know why the polish works, but it seems to. Will let you know how it goes next year....
Dave Stump
Captain Commanding
s/v Hanalei CD-30
Sounds like a good idea in theory, but your last comment about time is right on. It only takes about 2 minutes, after cleaning it with On&Off, to put on a coat of the stove polish and, this year at least, when Hanalei was pulled there were NO barnacles on the prop! She had been in since April 1st. and was pulled the 15th. of November. The sailboat in the slip right next to mine had a significant number on it's prop when pulled, but not as bad as what you describe happened in your marina. Maybe it has something to do with geographical location, I don't know.
I still don't know why the polish works, but it seems to. Will let you know how it goes next year....
Dave Stump
Captain Commanding
s/v Hanalei CD-30
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Chris Cram
Try this
I have had great results using parafin (sp) wax. I use a throw away tin plate on a hot plate,--- heat the parafin and paint on with a throw away paint brush. This lasts much longer than paint.
******Warning************
PARAFIN WAX IS EXTREMELY FLAMABLE So do not spill on your hot plate.
also be careful to spread evenly
Chris Cram
cccobx@prodigy.net
******Warning************
PARAFIN WAX IS EXTREMELY FLAMABLE So do not spill on your hot plate.
also be careful to spread evenly
Chris Cram
cccobx@prodigy.net
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Al Smith
What kind of stove polish?
Dave or Matt:
What kind of stove polish are you all using? Also, where are you all located? We have a CD33 on the Chesapeake Bay and wonder whether the warmer water would produce the same results.
Thanks, Al
saylr@mindspring.com
What kind of stove polish are you all using? Also, where are you all located? We have a CD33 on the Chesapeake Bay and wonder whether the warmer water would produce the same results.
Thanks, Al
saylr@mindspring.com
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Clay Stalker
Re: Sounds good, but...
What kind of stove polish is this and where did you get it? I think I might try this....D. Stump, Hanalei wrote: Matt,
Sounds like a good idea in theory, but your last comment about time is right on. It only takes about 2 minutes, after cleaning it with On&Off, to put on a coat of the stove polish and, this year at least, when Hanalei was pulled there were NO barnacles on the prop! She had been in since April 1st. and was pulled the 15th. of November. The sailboat in the slip right next to mine had a significant number on it's prop when pulled, but not as bad as what you describe happened in your marina. Maybe it has something to do with geographical location, I don't know.
I still don't know why the polish works, but it seems to. Will let you know how it goes next year....
Dave Stump
Captain Commanding
s/v Hanalei CD-30
cstalker@cheshire.net
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D. Stump, Hanalei
Re: It's just regular liquid.....
stove polish, the kind you would use to blacken a pot-belly stove. I believe it's simply carbon black or graphite in some type of solvent. I don't know the brand name, but will look at the bottle this weekend and get back to you. Also, in warmer water, will it work? Don't know, but a lot of this problem does appear to be geographical in origin. Some people get a LOT of growth, from what I'm hearing, and some get almost none. So, will the polish work in the Chesapeak, probably, but you folks down there are famous for growing oysters!!
I like the idea of parafin wax, sounds like it might be worth a try, but watch out for burns and burning.
Dave Stump
Captain Commanding
s/v Hanalei CD-30
I like the idea of parafin wax, sounds like it might be worth a try, but watch out for burns and burning.
Dave Stump
Captain Commanding
s/v Hanalei CD-30
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Matt Cawthorne
location
Al,
My process was tested on my boat which spends most of it's life on the chesapeake between Rock Hall and the Choptank river. It has been to Bermuda one time since the Coating was on and there were no Barnacles on the blades that year either. The hub sometimes gets barnacles on it but that does not affect the propellers performance in any significant way.
Matt
Mcawthor@bellatlantic.net
My process was tested on my boat which spends most of it's life on the chesapeake between Rock Hall and the Choptank river. It has been to Bermuda one time since the Coating was on and there were no Barnacles on the blades that year either. The hub sometimes gets barnacles on it but that does not affect the propellers performance in any significant way.
Matt
Mcawthor@bellatlantic.net
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Matt
Re: Careful around stainless steel
Dave,
Be careful if the stove polish has carbon in it. Keep the polish off of stainless steel shafts, particularly around the joint between that and the prop. I don't know for certain that it would be a problem, but Carbon is all the way on the noble end of the galvanic series. Anything that it is in contact with will start to disolve, particularly if the zinc were to come off (yeah, it happened to me one year). That joint with the prop could be a perfect location for crevice corrosion if it was primed with carbon.
The carbon may be the reason that the process works. It could be that the galvanic action with the carbon is forcing local oxidation of the prop despite the zinc(high local voltage gradients). It may be that the prop gets a healthy coating of oxide very quickly and that lasts the season.
I eagerly await the posts on this next fall. Less work is better.
Matt
Mcawthor@bellatlantic.net
Be careful if the stove polish has carbon in it. Keep the polish off of stainless steel shafts, particularly around the joint between that and the prop. I don't know for certain that it would be a problem, but Carbon is all the way on the noble end of the galvanic series. Anything that it is in contact with will start to disolve, particularly if the zinc were to come off (yeah, it happened to me one year). That joint with the prop could be a perfect location for crevice corrosion if it was primed with carbon.
The carbon may be the reason that the process works. It could be that the galvanic action with the carbon is forcing local oxidation of the prop despite the zinc(high local voltage gradients). It may be that the prop gets a healthy coating of oxide very quickly and that lasts the season.
I eagerly await the posts on this next fall. Less work is better.
Matt
Mcawthor@bellatlantic.net
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Matt
Re: Don't use this on a stainless shaft
I forgot to mention. Do not use this on the prop shaft if it is stainless. If the coating peels you could get a local 'crevice' which could set up agressive corrosion.
Matt
mcawthor@bellatlantic.net
Matt
mcawthor@bellatlantic.net
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D. Stump, Hanalei
Re: Stainless steel shaft on a Cape Dory...NEVER!!!.....
Matt,
No Stainless on Hanalei. You should note, there doesn't appear to be any galvanic effect on the prop or shaft at all. In fact, my Perry Zinc nut is still half there after being installed new this past Spring.
I suspect, without any proof, that the stove polish is effective because it is simply slippery! Hanalei is out of the slip at least once a week all season, and if slippery is the reason, the little running of the diesel we do is enough to "blow off" the critters! Anyhow, it does seem to work...maybe some of the Chemists or Metal specialists will comment.
Hey, did you see the answers Catherine M. posted in response to my query about code signal flags(see below)? This is really a neat board, good thing it is winter and we all have time away from sailing to contemplate the Universe(of sail)....
Dave Stump
Captain Commanding
s/v Hanalei CD-30
No Stainless on Hanalei. You should note, there doesn't appear to be any galvanic effect on the prop or shaft at all. In fact, my Perry Zinc nut is still half there after being installed new this past Spring.
I suspect, without any proof, that the stove polish is effective because it is simply slippery! Hanalei is out of the slip at least once a week all season, and if slippery is the reason, the little running of the diesel we do is enough to "blow off" the critters! Anyhow, it does seem to work...maybe some of the Chemists or Metal specialists will comment.
Hey, did you see the answers Catherine M. posted in response to my query about code signal flags(see below)? This is really a neat board, good thing it is winter and we all have time away from sailing to contemplate the Universe(of sail)....
Dave Stump
Captain Commanding
s/v Hanalei CD-30