Propeller paint

[zoidberg]

I'm prep'ing to apply antifoul paint to a newly-cleaned and wire-brush abraded 3-blade prop. As I have some Hammerite Special Metals Primer, I've started with that, and a first coat of Velox White.

But how many other coats to apply on top?

Some suggest two, some suggest four in total. Any pros and contras....?

 

[wilkinsonsails]

Ive put two minim and three some years .Always with good results
.

 

[Tranona]

Three was fine on mine. Was still working when I sold the boat nearly 3 years later having been in the water most of the time.

 

[Neeves]

Prep needs more than abrasion - if you touch the prop with your uncovered fingers, or the various coats, you will leave a thin film of grease and your hard work abrading and the paint you apply will be lost. It needs to be solvent washed and then finished with fresh water, then use rubber gloves.

I abrade with a wire brush, stainless wire, on an angle grinder - it produces a 'nasty' surface - but ideal to allow paint adherence.

Its all about the prep.

More, coatings, are better. When you apply the top coats you need to be fairly generous (and asking how many coats without knowing how much each individual applied) is as useful as asking how long is a piece of string.

Interestingly the 'active' ingredient is the same as Trilux (but Velox has more of it). Trilux is really not very effective, Velox is better - my conclusion is the more paint you apply the more active ingredient. However don't go mad - Velox is hardly cheap.

No AF is successful - unless you use the yacht.

Jonathan

 

[stuartwineberg]

I'm prep'ing to apply antifoul paint to a newly-cleaned and wire-brush abraded 3-blade prop. As I have some Hammerite Special Metals Primer, I've started with that, and a first coat of Velox White.

But how many other coats to apply on top?

Some suggest two, some suggest four in total. Any pros and contras....?

I use 2. At end of season trilux is gone, most hammerite still there, just a bit of calcium scale. Acid dip then 1 coat hammerite, 2 coats trilux again.

 

[geem]

We don't use anything just a tub of elbow grease. We keep it shiny by diving on it periodically. Polished within an inch of its life, it doesnt attract growth so fast. I never had any success with, prop paints when it was in the UK. Barnacles were its best friend

 

[zoidberg]

We don't use anything just a tub of elbow grease. We keep it shiny by diving on it periodically. Polished within an inch of its life, it doesnt attract growth so fast. I never had any success with, prop paints when it was in the UK. Barnacles were its best friend

That's a bummer! My mooring is on the River Tamar, which is so thick with nutrient runoff, one could grow potatoes.
Guess I'll just have to come sail in the Caribbean....

 

[vyv_cox]

I found that four costs of Velox chipped due to cavitation but two did not. Protection seems just as good

 

[RunAgroundHard]

Recent experience from seawaters around Crinan, Ardfern, Craobh area. I just followed the Velox instructions, two coats IIRC, on the Velox recommended primer, new prop. It works well, lasts for 2 years in the water, but does still attract some barnacles around the centre of rotation. Now, the old propellor was not subject to any paint and it did foul more heavily at Largs Marina, but not much more. I left the boat in for 3 years and on lifting that winter, un painted, it had barnacles all over, not uniform, nor solid layer, but well on its way to that. If you lift your boat annually and are not in an area known for significant growth it may not be worth it. From your potato growing claim, likely you will need it.

 

[zoidberg]

I found that four costs of Velox chipped due to cavitation but two did not. Protection seems just as good

NOW you tell me!
Guess what I was doing yesterday evening.....

 

[Neeves]

NOW you tell me!
Guess what I was doing yesterday evening.....

Don't be upset - we might not be comparing like with like. Its a scenario I had not considered. A slower running engine will not have the same cavitation issues. Its not only water temps, nutrient and salinity levels, pattern of usage of the yacht - but also engine or more specifically prop speed.

If you only use the engine for entering and leaving your mooring location but use the yacht it seems you will have different experience to someone who also uses their yacht often AND their engine more often and at high revs.


I cannot recall why, it was a long time ago (maybe 20 years ago), but I had followed International's instructions meticulously for a white epoxy coating over which I applied Trilux (before I had heard of Velox). I'd done this near Brisbane and then sailed/motor sailed back down to Sydney - with a lot of engine use. When I arrived at Sydney the props had lost about 75% of the carefully applied coating - and the bare patches glowed gold (but not for long). . At the time I never considered cavitation as being the cause. This experience instilled in my mind, maybe wrongly, that prep was critical and I started to use a stainless steel wire wheel on an angle grinder (and have been using it ever since) to provide as a good a key as possible.

Another part of my practice is to paint the prop off its shaft simply to keep the prepared, or painted, surfaces as clean as possible. Not quite true - I clean and abrade my wife does all the painting and I then re-assemble. We have 2 engines and carefully keep the 2 props separately and marked - getting the starboard prop on the port sail drive is a disaster.

Jonathan

 

[coveman]

That's a bummer! My mooring is on the River Tamar, which is so thick with nutrient runoff, one could grow potatoes.
Guess I'll just have to come sail in the Caribbean....

At least you can switch the engine on and have some chips!