Stabo
New member
We intend to put coppercoat on our sailboat. Is it feasible to apply coppercoat also on propeller, shaft and P bracket? Any experiences with adhesion, in particular?
Coppercoat on propeller
- Thread starter Stabo
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Tranona
Well-known member
No. The best coating for the Prop and P bracket is Velox, although Trilux can be successful for a season at a time on props. P brackets, because they don't move are usually fine if prepared properly, primed with Hammerite all metals primer and conventional antifoul. Not usually necessary to coat the propshaft as nothing much grows on that.
vyv_cox
Well-known member
Coppercoat advise against using their product on props, although I question their understanding of the metallurgical factors.
As Tranona says, I use Velox over Hammerite SMP on my prop and P bracket quite successfully in Greece.
As Tranona says, I use Velox over Hammerite SMP on my prop and P bracket quite successfully in Greece.
Stooriefit
Active member
Velox although not cheap definitely the way to go. Just make sure the prop is back to shiny metal before you apply the primer.
Stabo
New member
Thanks to all for the answers!
I have very good experience with Velox system ( primer+AF), however intention is to reduce the lift-out as much as possible. For that reason the application of the coppercoat also to the propeller, shaft an P bracket is tempting.
May I ask Vyv, if there are some galvanic corrosion related issues to be considered or its more adhesion problem. Would epoxy wash primer ( as for instance Epifanes epoxy metal primer with zinc phosphate) help ?
I have very good experience with Velox system ( primer+AF), however intention is to reduce the lift-out as much as possible. For that reason the application of the coppercoat also to the propeller, shaft an P bracket is tempting.
May I ask Vyv, if there are some galvanic corrosion related issues to be considered or its more adhesion problem. Would epoxy wash primer ( as for instance Epifanes epoxy metal primer with zinc phosphate) help ?
Tranona
Well-known member
I have my boat Coppercoated and the blades of the folding prop coated with Velox. The Velox performs in the same way as the Coppercoat - light slime easily washed off - no barnacles. Have not bothered with the hub as it does not foul as much as the blades and has little impact on performance and the saildrive housing is coated in Trilux which lasts a season and is not so critical leaving it longer.
Suspect the problem with bronze props is adhesion. Coppercoat needs a good epoxy base coating. Might be worth giving Ewan at AMC a call for a better explanation.
Suspect the problem with bronze props is adhesion. Coppercoat needs a good epoxy base coating. Might be worth giving Ewan at AMC a call for a better explanation.
Sandy
Well-known member
I have the boat out of the water at the moment. She was Copper Coated three years ago and has not been out of the water since then. The prop and shaft was left 'naked', very little marine growth even after moving less than 200 nm last year and 1,250 nm this. I have no plans to paint any snake oil on them in future.
vyv_cox
Well-known member
AMC suggest that putting Coppercoat on a prop may cause galvanic corrosion problems. I do not agree for two reasons. Firstly, pure copper is anodic to any likely prop materials, so if anything corrodes it will be the Coppercoat.
However, and secondly, the copper grains in Coppercoat are separated by the epoxy, so there is no possibility of galvanic corrosion.
It is adhesion that is the concern. I have applied Coppercoat directly to my P-bracket, where it lasted no time at all. The Hammerite etch primer product solved this fully. It is cheap and highly effective. Although applying epoxy over alkyd paints is normally not recommended, in this case it seems to work.
Daydream believer
Well-known member
If one coats a propeller with antifoul & the antifoul gets chipped in a particular area - ie the blade tip. I am told that if there is a situation where electrolytic corrosion is high- ie marinas etc- the prop could suffer isolated loss in a particular area. This can cause prop imbalance or damage to the prop.
This is why some suppliers prefer one NOT to apply antifoul paint to the prop.
I do not apply any finish to the prop & do not have a problem. However, I use the boat & it comes out of the water every year
This is why some suppliers prefer one NOT to apply antifoul paint to the prop.
I do not apply any finish to the prop & do not have a problem. However, I use the boat & it comes out of the water every year
vyv_cox
Well-known member
I have seen this said several times but I cannot see why it should be the case. Small anodes corrode more quickly than big ones with a large cathode but that is never going to be the case here.
tross
Active member
Why don't you take the prop off and have it copper plated ! In the long run it is a lot cheaper
Neeves
Well-known member
john_morris_uk
Well-known member
I agree with Vyv about adhesion. We had our P bracket copper coated when the hull and keel was done and the P bracket lost it's copper coat very quickly. This was despite being grit blasted back to bare bronze.
Stabo
New member
Thanks to all for the useful comments!
Copper electroplating of the propeller sounds interesting. It looks like this is widely used technique - even in such a small town like Kalamata, where boat will overwinter, I found a company which deals with it.
May I kindly ask Vyv to comment .
Copper electroplating of the propeller sounds interesting. It looks like this is widely used technique - even in such a small town like Kalamata, where boat will overwinter, I found a company which deals with it.
May I kindly ask Vyv to comment .
tross
Active member
Vyv did an articue for PBO I think, a few years back
Bodach na mara
Well-known member
I'll try to get to the boat and photo the prop shaft and post it. Both prop and shaft were coated with Velox in the spring, as has been my practise for the last few years. The prop is clear but the shaft is covered with barnacles. Quite large, strong ones that are firmly stuck on.
Tranona
Well-known member
Was it the Velox that had failed? Barnacles are unpredictable things. There can be years when there are none, but I can remember the odd year when uncoated props were covered in them.
Neeves
Well-known member
propeller anti foul
About Post No 18
Google is your friend
You might be able to work out which issue the article was published in - and then its a visit to your local library or buy the article.
I think Vyv's test and article was a fixed blade prop - I'm not sure how the various polymers that are used in folding props would survive the electroplating process.
Jonathan
About Post No 18
Google is your friend
You might be able to work out which issue the article was published in - and then its a visit to your local library or buy the article.
I think Vyv's test and article was a fixed blade prop - I'm not sure how the various polymers that are used in folding props would survive the electroplating process.
Jonathan
vyv_cox
Well-known member
Away from home now, will post copper plating info next week.
Stabo
New member
Very kind, tanks.
