Underwater metal and paint

Nov 3, 2018
82
Cape Dory, Albin 300ms Motorsailer, Vega Baltimore
I have always hear that one shouldn’t use regular bottom paint on props due to potential corrosion issues and I’ve always used other coatings on my props. However looking at the through hulls the other ay I realize that I usually just slather them with bottom paint and looking at other boats in the yard it appears this is what most do. So, should I be using the same coating (Petite) on the through hulls that I use on the prop or am I overthinking this an just slather some more bottom paint on the through hulls? What say you O great and good forum?
 
Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
If those thru hulls are being used for bonding any groundings to seawater, do not paint. Otherwise, slather away. But, if you decide you need an electrical connection to the sea and you slather you thru hull, then you will be SOOL!
 
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Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
.............so, should I be using the same coating (Petite) on the through hulls that I use on the prop................
My boat yard applied Prop Speed Primer and Prop Speed Clear Coat to prevent fouling of propellers, shafts, struts and more to give the running gear a long-lasting, ultra-smooth surface.
 
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Nov 3, 2018
82
Cape Dory, Albin 300ms Motorsailer, Vega Baltimore
My boat yard applied Prop Speed Primer and Prop Speed Clear Coat to prevent fouling of propellers, shafts, struts and more to give the running gear a long-lasting, ultra-smooth surface.
did they paint the through hulls too?

Brian D, thanks for the reply. The through hulls are all bonded together which leads to the ships common ground (connected to seawater), so I take it that no paint is the answer. I’ll have to remove paint the PO applied. Redoing the bonding connections is on my to do list.
 
Jan 11, 2014
11,324
Sabre 362 113 Fair Haven, NY
Another option is to use a copper free antifouling paint. Steel and aluminum boats can not use copper based AF paints.
 
Jun 25, 2004
475
Hunter 306 Pasadena MD
This thread caused me to go back and search the archives for prop treatments. In the past, I've painted with regular ablative bottom paint and not painted: never noticed any difference. I tried some spray treatment one year, but it was a long time ago. Anyway, based on old postings, today I tried 3 coats of Rustoleum cold galvanizing spray paint on our bronze prop. Seems to be highly recommended by some other sailors in the high-fouling Chesapeake environment. Cost 8 bucks and I used way less than half a can. Splashdown is tomorrow morning!
 
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Nov 3, 2018
82
Cape Dory, Albin 300ms Motorsailer, Vega Baltimore
This thread caused me to go back and search the archives for prop treatments. In the past, I've painted with regular ablative bottom paint and not painted: never noticed any difference. I tried some spray treatment one year, but it was a long time ago. Anyway, based on old postings, today I tried 3 coats of Rustoleum cold galvanizing spray paint on our bronze prop. Seems to be highly recommended by some other sailors in the high-fouling Chesapeake environment. Cost 8 bucks and I used way less than half a can. Splashdown is tomorrow morning!
Thanks for the tip on Rustoleum. In the past I used a Petite product-way more than 8 bucks and in my opinion not very effective.
 
Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
Not exactly relevant (but maybe). I have used the Rustoleum cold galvanized on all of my boat trailers with very good results. It is a good product. The only underwater metal I have on my boat is the ballast tank valve.... so now I'm thinking maybe I should paint it with rustoleum as well? I have shore power but I don't think I have a ground to water anyplace on my boat.
 
Jun 25, 2004
475
Hunter 306 Pasadena MD
Thanks for the tip on Rustoleum. In the past I used a Petite product-way more than 8 bucks and in my opinion not very effective.
Just to be clear: I'm not recommending this. I'm just saying that several (I think) well-respected forum members have recommended either Rustoleum or Ace Hdwre cold galvanizing spray, and I dug up their postings and gave it a try this year. I hope it works, but in the Chesapeake, nothing much seems to work for me unless I dive on the boat or hire a diver a couple of times a season.
 
Feb 10, 2004
3,919
Hunter 40.5 Warwick, RI
I have posted that I use either the Rustoleum or the Ace Cold Galvanize. Read the label - it is exactly the same stuff as the Pettit Barnacle Spray. I have used a Prop Speed type of coating once and was very disappointed. It lasted only one year for me and did not meet my expectations. The Cold Galvanize is about as good as you are going to get these days or until something that is actually better becomes available. The governments have prohibited all the good old stuff that actually worked.
 
Nov 3, 2018
82
Cape Dory, Albin 300ms Motorsailer, Vega Baltimore
Just to be clear: I'm not recommending this. I'm just saying that several (I think) well-respected forum members have recommended either Rustoleum or Ace Hdwre cold galvanizing spray, and I dug up their postings and gave it a try this year. I hope it works, but in the Chesapeake, nothing much seems to work for me unless I dive on the boat or hire a diver a couple of times a season.
I have a can of Pettit barnacle spray, so I’ll just go with that until it’s used up. I also sail in the Chesapeake an haven’t found much that works to keep the prop and running gear free of growth. Once the Pettit is gone I’ll give the rustoleum a try.

Thanks for all the input everyone!