Antifoul a brass prop??

[Jasonbbo]

Hi guys , got a new yacht (new to me) and it has a shaft driven brass 2 blade will I antifoul the prop? I’ve seen a few brass props on boats being lifted out in the yard some anti fouled some not, the ones that haven’t been seem to have a lot more weed and barnacles on them. But lots of the boats still polish them ready for next season.

my last yacht had a sail drive with an alloy prop the first year I took it out of the water you couldn’t see the prop anymore it was just a big mass of barnacles so I antifouled it every year after that

So what’s the done thing with brass props? Boat will be taken out water Oct- April every year..

 

[vyv_cox]

I have antifouled my Bruntons prop for the past 10 years. Adhesion to brass/bronze is difficult, needs an etch primer. Hammerite Special Metals works well. I then use Velox in Greece but others may work better in other areas

 

[Jasonbbo]

I have antifouled my Bruntons prop for the past 10 years. Adhesion to brass/bronze is difficult, needs an etch primer. Hammerite Special Metals works well. I then use Velux in Greece but others may work better in other areas

That’s a good idea using hammerite as a primer!!

 

[Jonny A]

I antifoul mine, no primer just the remains from the previous year, lightly sanded back.

 

[Pye_End]

Velox +1

 

[jwilson]

Coat of high % zinc primer then quality eroding AF. At the next liftout most of the AF will be gone, and you sand and scrape back the primer ready for another year. Never had any significant fouling on prop blades with 8-9 months afloat in a high fouling area. I suspect but cannot prove that the zinc in the primer may also help to slow down eventual dezincification of prop blades (usually bronze not brass).

This is on a sailing yacht, fast motorboats seem to prefer high polish for max efficiency, and also the higher speeds maybe let polished props work OK for avoiding fouling. Certainly just being polished does not deter fouling much on sailing boat props: I tried it one year - never again.

 

[vyv_cox]

Our prop at end of season before pressure washing. 103 hours of engine in the season, about 6 months afloat in Greece. Hammerite Special Metals primer, the red paint visible in a few places, does not contain zinc as far as I know. The Velox lasts very well if not applied too thickly, in which case it will chip. In early years I experimented with other antifoulings, none of which lasted well.

The majority of fixed yacht propellers and P-brackets are made from manganese bronze, actually a brass with small additions of other metals. Some do not even contain manganese! Some after-market props are bronze, aluminium bronze or even, usually for mobos, nickel aluminium bronze.

 

[jwilson]

Nothing against Velox: just never used it as I always have ordinary AF (Int Micron or Seajet 33 - depending which is cheaper that year) in hand every spring. Also already have the high zinc primer for rusty bits of keel. Maybe my parsimonious Scot is coming out.....

 

[Jasonbbo]

thanks guys , looks like I’ll be anti fouling going by your recommendations, I’ll prime the prop with hammerite metal primer and coat with Velox thanks for taking the time to reply especially the lengthy ones. Can I ask how many coats of Velox do you guys apply?

 

[vyv_cox]

thanks guys , looks like I’ll be anti fouling going by your recommendations, I’ll prime the prop with hammerite metal primer and coat with Velox thanks for taking the time to reply especially the lengthy ones. Can I ask how many coats of Velox do you guys apply?

Two only

 

[PetiteFleur]

I've used Velox Plus for the last few years and it works OK - still get a few barnacles and a bit of weed at the seasons end but not excessive. Velox Plus is now expensive and only available in 500ml tins instead of the original 250ml - if you can find anyone selling it. Still available from the EU but very expensive!
Seamark Nunn have 500ml Black and Grey on offer at the moment at £39.95 but no more in the future.

 

[Jasonbbo]

I've used Velox Plus for the last few years and it works OK - still get a few barnacles and a bit of weed at the seasons end but not excessive. Velox Plus is now expensive and only available in 500ml tins instead of the original 250ml - if you can find anyone selling it. Still available from the EU but very expensive!
Seamark Nunn have 500ml Black and Grey on offer at the moment at £39.95 but no more in the future.

Thanks for that bit of info

 

[Birdseye]

odd that you need antifoul on a brass prop when Coppercoat works well on hulls.

 

[vyv_cox]

odd that you need antifoul on a brass prop when Coppercoat works well on hulls.

It's copper oxy-chloride that provides the antifouling. This does not form on brass

 

[Neeves]

The Colour of AF makes not an iota of difference to performance but white offers the ability to see, easily, when the prop, or any AF, is fouled.

Jonathan

 

[stuartwineberg]

That’s a good idea using hammerite as a primer!!

+1 for hammerite, I then spray 2 coats trilux sadly now discontinued, using Sml paints version but no idea how good that will be

 

[Sandy]

Never antifouled my prop.

 

[superheat6k]

Prop fouling on powerboats with hefty engines is always an issue. Best performance for me has been Hammerite Special Metals primer with Velox on top.

Based on the advice about declining availability I'm going to buy some now whilst it is still available. Once used I will store the tin upside down to keep the skin at the bottom end of the tin.

 

[vyv_cox]

Prop fouling on powerboats with hefty engines is always an issue. Best performance for me has been Hammerite Special Metals primer with Velox on top.

Based on the advice about declining availability I'm going to buy some now whilst it is still available. Once used I will store the tin upside down to keep the skin at the bottom end of the tin.

I use so little of it that it lasts very well. I bought a small tin in 2013 when I first tried it and there is still about half of it left.

 

[Alpha22]

The flip side is painting bronze props MAY cause crevice crack erosion and cause blades to snap off... I've seen it happen, but probably only a problem on higher stress props on high performance boats.