Copper plated props?

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Keith

Keith

Guru
Joined
Oct 5, 2007
Messages
2,715
Vessel Name
Anastasia III
Vessel Make
Krogen 42
Has anyone tried copper plating a bronze or other metal prop? I'm thinking this might be a long lasting anti-fouling treatment, but don't know about the corrosion potential. But then if we're painting props with a copper based anti-fouling coating...
 
Tap Tap Tap. Hello???
 
A google search brings up a mixed bag of results. Some have done it and claim 5 years and no growth and some saw no noticeable improvement, The Aussies also have a patent pending on a particular application.
 
I suppose hanging a copper fitting off your dock on a string would give you a good idea in 6 months to a year. I may try that at my marina and see what happens. Cool thought Keith :thumb:
 
It's an interesting idea but I don't think it would be much of an improvement over a bare bronze prop. After all, bronze is mostly copper anyway.
 
Seems odd that a bronze propeller which is mostly copper and some small amount of another metal (probably tin) would not protect as well as pure copper. But maybe the bronze alloy stops the chemical reaction of copper and seawater which form the protective coating?

The 18th century practice of sheathing wood hulled ships with copper plate was a little different, as the copper plate was meant to stop ship worms, Teredo's and marine growth from boring into the wood hulls.

It would be a good to know fact. Do we have any metallurgist on the forum?
 
What about copper epoxy antifoul?

Sand and coat the prop in pure epoxy, a couple of coats and then when it has kicked, go over the top with the copper epoxy.
That way the first few coats of pure epoxy works as a barrier coat to the dissimilar metals.
 
Keith said:
Has anyone tried copper plating a bronze or other metal prop? I'm thinking this might be a long lasting anti-fouling treatment, but don't know about the corrosion potential. But then if we're painting props with a copper based anti-fouling coating...
Click to expand...

Simply said, the way copper electro winning/plating works requires a pure metal such as Fe, Cu Pb or Pt as the starter sheet. Pure metal props have their own problems which is why alloys of copper are used. A better question is why not use an all copper prop? Answer, in larger sizes the prop would be so thick it would be ineffective. Same as Al props are limited to something less than 17"

Copper won't plate to the alloys. Having worked in the zinc and copper plating (refining) business I can only say if copper refining were easily done using a bronze or nickel alloy anode it would be pretty revolutionary.

While a few prop barnacles may seem a problem to some, in the big picture they are easily dealt with using paint, slick stuff or elbow grease.
 
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Last haul out they painted my running gear with Pettit Zinc Coat, which comes in a bomb can. According to my diver it worked great for two seasons on the props and four years on the shafts here in the PNW.

It was $26 a can and for twin engines took two cans to complete the recommended 2 -3 coats. It's $35 a can now and I don't know if I will use it again. The diver checks my gear twice a year and re-zincs the boat once a year and cleans props and shafts anyway. So barnacles on the gear is not a big deal here.:confused:
 
I wonder if it would be worth trying to epoxy on a copper foil if plating is out....
 
All paint products must list ingredients and make available to consumers. When I check the Mil Spec zinc paint from Pettit the zinc paint at Lowes was the same paint at $ 8.29 for same size can. Many yards on East coast are using on all underwater hardware. Time will tell..
 
I don't think using copper coatings on bronze props is a good idea because of what may take place w the copper and bronze together. I'm quite sure there will be corrosion or some other undesirable result.

Interlux however outlines a process for painting bronze props w anti-fouling paint.

1. Sand and clean
2. One coat of surface primer - Vin-Lux primewash.
3. Three to four coats of primer. Interprotect 2000E
4. Three coats of antifouling - Tri-Lux 33

The Tri-Lux 33 is the very common paint used for aluminum props. I don't know if it's copper or tin based AF but one look at the can should reveal. I'm almost positive Tri-Lux 33 is what I put on the bottom of my aluminum skiff.
 
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manyboats said:
I don't think using copper coatings on bronze props is a good idea because of what may take place w the copper and bronze together. I'm quite sure there will be corrosion or some other undesirable result.
Click to expand...
Post 8 :facepalm:

Sand and coat the prop in pure epoxy, a couple of coats and then when it has kicked, go over the top with the copper epoxy.
That way the first few coats of pure epoxy works as a barrier coat to the dissimilar metals.
Click to expand...
 
Parmenter said:
post 8 ;)

multiseason antifouling 10 years protection hard wearing copper filled epoxy resin copper antifoul

DIY Yachts • View topic - Home made copper antifoul

Self made Copper-Epoxy-mix as Antifouling? - And the 'same' ready made products? - Boat Design Forums
Click to expand...

With just a scan of the first pages...didn't see anything about foil...just copper mixed in with epoxy....

Not sure copper would have a bad reaction with a bronze prop...many just put copper based antifouling paint directly onto the prop with no barrier coat with no ill effects.
 
Bronze propellers are an extremly rare animal. I very much doubt if any of us have them. Propeller bronze is Mangasnese Bronze which is actually a member of the brass family with a zinc content of about 40%. Manganese bronze is used because it is cheaper and true bronze is too hard (and difficult) to tune.

Professional Boat Builder has a very good article on brasses an bronzes The article has a very good photo of electrolytic corrosion and its effect on de-zincifying "bronze" propellers.
 
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Mine are 3 bladed, Michigan Wheel - Nibral

Nibral is an alloy of nickel, bronze, and aluminum
 
OK...so my "bronze" prop is manganese bronze (lot's of zinc in it)....the zinc is what galvanic action attacks first...so again...I wonder what the issue would be of trying to epoxy copper foil to a propeller blade?

Just like copper painting a prop only this would probably have more insulation with a thin coat of epoxy between them. The copper should wear better and longer than paint.

Sheathing hulls in copper is an "old time" method for wood hulls...so I wonder how a relatively slow turning trawler prop would handle it?
 
psneeld said:
OK...so my "bronze" prop is manganese bronze (lot's of zinc in it)....the zinc is what galvanic action attacks first...so again...I wonder what the issue would be of trying to epoxy copper foil to a propeller blade?

Just like copper painting a prop only this would probably have more insulation with a thin coat of epoxy between them. The copper should wear better and longer than paint.

Sheathing hulls in copper is an "old time" method for wood hulls...so I wonder how a relatively slow turning trawler prop would handle it?
Click to expand...

Which is exactly what copper loaded epoxy does.

Each year when you lightly sand the surface you have basically, fresh copper foil
 
Parmenter said:
Which is exactly what copper loaded epoxy does.

Each year when you lightly sand the surface you have basically, fresh copper foil
Click to expand...

If it works so well...why doesn't everyone use it including those where budget is not a consideration????...

In all the years copper coat has been out...I have not seen one vessel done with it...nor talked to one person who has actually used it or even knew someone that did.

While in naval engineering for the USCG...the big push for new bottom coatings was on ...and NO ONE ever discussed copper coat...

so I have to ask ...if so great...why the world's greatest secret?
 
psneeld said:
In all the years copper coat has been out...I have not seen one vessel done with it...nor talked to one person who has actually used it or even knew someone that did.
Click to expand...

Oh, I've seen it plenty. And I wouldn't wish it on my worst enemy. It may work someplace, but that place ain't here.
 
I tried a copper loaded epoxy many years ago. It may have been Copper Coat, I don't remember. It wasn't worth the time or effort. Really cheap bottom paint would have worked just as well. I figured when I tried it, that if it wasn't good at keeping growth off, at least it should prevent blisters. It didn't do that either. It was a complete waste of time and money.

I've tried a lot of different coatings on my propeller. The only one I'll use now is Prop Speed. It will keep my propeller clean for a year or more. It also seems to be good for a few RPM and half a knot over a clean uncoated or painted propeller.
 
fstbttms said:
Oh, I've seen it plenty. And I wouldn't wish it on my worst enemy. It may work someplace, but that place ain't here.
Click to expand...
I wont use it because of the weight and cost of it but I also know plenty that have used it.
 
psneeld said:
If it works so well...why doesn't everyone use it including those where budget is not a consideration????...

In all the years copper coat has been out...I have not seen one vessel done with it...nor talked to one person who has actually used it or even knew someone that did.

While in naval engineering for the USCG...the big push for new bottom coatings was on ...and NO ONE ever discussed copper coat...
Click to expand...
A bit like sticking copper foil on with epoxy? ;)
 
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