Velox prop antifouling again

vyv_cox

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Now retired, anchor swallowed.
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End of our fourth season using Velox. The original Hammerite special metals primer has not been touched. This year I sanded back last year's coatings and applied two new ones to prop and P-bracket. We launched on May 11 and lifted out on September 29. The boat spent the whole of August in the marina at Leros, during which time the hull became fairly well fouled, since brushed off by swimming using mask and snorkel. The Velox needed no treatment and was not touched. At lift out the P-bracket was lightly fouled at the junction with the hull. No other fouling at all, whereas previously with conventional hard A/F there were always considerable deposits of tubeworm. Photo shown before pressure washing.

Prior to August our log impeller was fouled a few times by tubeworm shell. I applied a single coat of Velox, since then it has remained clear.

Our Coppercoated keel, now 7-8 years old, attracts some tubeworm that gives other forms of fouling a toe-hold. Still not too bad after nearly 5 months in warm water, but further treatment will be needed before too long.
 
Interesting. I spent quite a bit of money and a lot of time in preparation – following instructions to the letter including primer – on Prop O Drev this season. This for a Trusty 23 displacement motor cruiser in the Moray Firth. It was a complete waste of time with areas of the prop bare within weeks and tubeworm and plenty of mini barnacles present at lift out.
 
I also applied Velox antifouling to my prop last year and I was due to be present when taken out to view before power washing - unfortunately the boatyard took it out a day earlier so didn't see fouling, but there were lots of barnacles on the velox. Painted again this spring and hopefully will be around when hauled out but I suspect there is some fouling as max revs are down about 300rpm.
 
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End of our fourth season using Velox. The original Hammerite special metals primer has not been touched. This year I sanded back last year's coatings and applied two new ones to prop and P-bracket. We launched on May 11 and lifted out on September 29. The boat spent the whole of August in the marina at Leros, during which time the hull became fairly well fouled, since brushed off by swimming using mask and snorkel. The Velox needed no treatment and was not touched. At lift out the P-bracket was lightly fouled at the junction with the hull. No other fouling at all, whereas previously with conventional hard A/F there were always considerable deposits of tubeworm. Photo shown before pressure washing.

Prior to August our log impeller was fouled a few times by tubeworm shell. I applied a single coat of Velox, since then it has remained clear.

Our Coppercoated keel, now 7-8 years old, attracts some tubeworm that gives other forms of fouling a toe-hold. Still not too bad after nearly 5 months in warm water, but further treatment will be needed before too long.

Thank you for sharing your results. Very impressive. Regarding the application of the Hammerite special metals primer, how did you prepare the prop before applying, what grade of abrasive? The instructions for the Velox primer says to use 80 grit abrasive which I am reluctant to use as I normally use 300+ grade and leave the prop bare so if after trying velox I decide to go back to no coating it will need a lot of work to get rid of the deep scratches. Thanks again.

Colin. Www.solocoastalsailing.co.uk
 
Yes, it's a Bruntons Autoprop, bought in 2002.

I abraded the prop with 180 grit wet and dry when the primer was first applied four seasons ago. For the first year I applied four coats of Velox, as instructed. At the end of the season there was considerable chipping/pitting of the Velox, through which the primer was visible. Subsequently I have taken most of the Velox back to the primer, again with 180 grit, then applied two coats of Velox. This seems to be a good coating, enough to remain through a season of 100 - 150 hours of motoring but without chipping.
 
I used Velox for the first time this year and although the result was better that previous antifoulings it wasn't perfect. If you look at the photos you can see large areas where the primer and paint has been lost and there is still some growth on the paint. I applied three coats of paint. Because the propeller gearing is greased, maybe I didn't remove the last traces of grease on the blades before applying the primer. Whatever I did, I'll have to try harder next year.

To spread costs, I shared the tin with two other club members. They had similar results although they were slightly more successful than I was.



 
I used Velox for the first time this year and although the result was better that previous antifoulings it wasn't perfect. If you look at the photos you can see large areas where the primer and paint has been lost and there is still some growth on the paint. I applied three coats of paint. Because the propeller gearing is greased, maybe I didn't remove the last traces of grease on the blades before applying the primer. Whatever I did, I'll have to try harder next year.

To spread costs, I shared the tin with two other club members. They had similar results although they were slightly more successful than I was.

There is no doubt that getting paint to stick to manganese bronze and similar alloys is not easy. I have not used Velox' own primer but used Hammerite special metals because I had a new tin of it. This has proved to be most successful. However, since then the primer has been reformulated and is now water based, so I do not know if it is as good as it was.
 
I painted my 3 blade flex-o-fold prior at the start of this season. First time I've ever painted a prop. One of the main reasons I wanted to paint it was to reduce the surface area of the prop as a cathode. Last season, the prop anode was well eaten away.

I used Primocon undercoat and Trilux 33 anifoul. It seems to have lost most of the paint during the 35 mile journey from yard to marina. I didn't use the boat much this season. I dived under her in October just prior to haul out and found sea squirts growing happily on one of the blades!
 
Prior to August our log impeller was fouled a few times by tubeworm shell. I applied a single coat of Velox, since then it has remained clear.
Interesting. My log impeller doesn't look like it has ever been antifouled and this year it has only intermittently worked. I was thinking of using Velox which I already have to hand but noticed this in the instructions for the Airmar DST800 :

Aquatic growth can accumulate rapidly on the multisensor’s surface reducing performance within weeks. Surfaces exposed to salt water must be coated with anti-fouling paint. Use water-based anti-fouling paint only. Never use ketone-based paint, since ketones can attack many plastics possibly damaging the sensor.

Would you happen to know whether Velox contains ketones, Vyv ? Also, did you prime before applying the Velox to the transducer and if so what did you use ?

Boo2
 
Would you happen to know whether Velox contains ketones, Vyv ? Also, did you prime before applying the Velox to the transducer and if so what did you use ?

Boo2

I can only say that it doesn't smell of ketones (acetone, MEK) and it dries very quickly, which suggests that there would be minimal attack even if it did. I did not prime it, just applied a single coat of Velox. Seemed to be still in place when we lifted out.
 
Interesting. My log impeller doesn't look like it has ever been antifouled and this year it has only intermittently worked. I was thinking of using Velox which I already have to hand but noticed this in the instructions for the Airmar DST800 :

I've used Trilux on my DST800. Trilux has xylene as the solvent, and it doesn't seem to damage the plastic. It's best to take the spindle out of the transducer and paint the impeller and housing separately.
 
Another vote for Velox. Had a look at the prop with the GoPro today after 8 months immersion and 100 hours motoring this year and then sitting idle for the last month.
Bit of slime but nothing else.
Entertainingly hit and miss waving the boat hook with the camera clamped on the end under the boat trying to find the prop.
Andy
 
I tied Velux over hammerite metal primer after Vyv's glowing recommendation. The Hammerite primer was fantastic. Never met anything that stuck to bronze so well. However, Velux was a sad disappointment. Most of it had not stayed stuck to the hammerite and where it had it was covered in barnacles. There were no barnacles attached to the bare hammerite and very few to the trilux on the prop hub and saildrive leg. I still have quite a bit of Velux left and I will try applying it to a fresh coat of hammerite before it has set but I cannot say I hold out much hope. By the end of the season I had lost at least half a knot in boat speed under motor and that was not due to hull fouling as I had managed to keep the hull pretty clean all season using a Hullsmaid (precursor to the Brizo) on Seajet Emporer. It might be worth trying the hammerite on its own given that nothing appears to stick to it. Boat is base on the Orwell.


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That's disappointing. Looks like an adhesion problem. I think it's worth trying a different approach, maybe abrade the Hammerite before applying the Velox.

I had the same thought about using Hammerite on its own as an A/F and painted a small area on the keel to try it. Unfortunately it didn't work.
 
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