Prop Speed

[Neeves]

Prop Speed, a silicone based coating for props, is making slow but steady inroads into the market. It has been announced it will be used on Nautor Swan vessels. There are alternatives, Prop Gold, aka Prop One, is another. It was originally only sold to professional applicators but, I believe, you can buy small kits (enough for 2 props - but I'm not sure it 'keeps'). Another alternative is Velox, and between Velox, a 'conventional' AF, they are slowly becoming the AF of choice for props, and other running gear.

Both Velox and Prop Speed need very careful preparation and application - follow the instructions! Neither has the life of a good application of a top of the range AF on the hull, so the prop will start to foul before you actually need to re-apply AF on the hull.

If you use a silicone treatment on the prop the prop then becomes difficult to coat with a conventional AF as it is very difficult to remove all traces of silicone. There is also a suggestion that the silicone formulations contain chemicals, or a chemical, that might be carcinogenic, so care needs to be taken when removing a silicone coating (good dust suppression and protective clothing).

I have trialed Prop Speed, Prop One and Velox - they seem to have a similar life, they both need care to apply, none are as 'impressive' as a good top of the range AF that you would use on the hull. As with all AF they need to be 'used' - leave your vessel idle - it will develop growth. Being silicone the coating is soft and susceptible to damage (but if you hit something in the water, a bit of robust seaweed - you will damage the Velox coating). Any damage will be a source of fouling. I have also tried Lanolin - it seems to form a base for increased fouling.

Both coatings, Velox and Prop Speed are expensive - and if you extend usage to your Saildrive then you need a lot of silicone or Velox.

Personally I prefer Velox, its easier to apply and is not an impediment if a new product comes on the market.. I wonder if there is a spray on coating that could advantageously applied to Velox that might give Velox an extended life. I recall reading a trial conducted by Jotun that suggested that a good seal on a sail drive, a good epoxy coating, might allow the sail drive and props to be coated with a copper based AF...... but I cannot find the article

Jonathan

 

[B27]

Wasn't silicone AF a craze in about 1997?

 

[Neeves]

Wasn't silicone AF a craze in about 1997?

I'm not sure of the date - but some years ago it was believed to be the best thing since sliced bread. It was extensively used on large commercial vessels - but the enthusiasm has waned (for usage on some large commercial vessels) and some have reverted to conventional AF.

As far as I am aware there were a number of trials of silicone on hulls of leisure vessels, sail, but the results were never highly publicised and the enthusiasm has waned. Draw you own conclusions. Prop Speed has bucked that trend (of interest waning) - but they are addressing a very niche market. Its fairly common place on medium to large leisure MoBos here in Oz (those where the 'AF' is conducted by a boat yard).

Prop Speed does work, it does what is meant to do. But I did not find it any better than Velox, I'm a certificated applicator courtesy of Prop One, then known as Prop Gold, as I was comparing these silicone coatings with conventional AF viz Velox, Trilux etc and Velox is more user friendly. I've seen video of commercial vessels being treated with silicone - operators are encased in sealed HazMat suits with personal air lines - hardly 'PBO', more 'nuclear accident'.

If restrictions increase on use of conventional AF, on props and hulls - silicones may still have their day - I would not write them off. The 'test' work has been done - it could be 'THE answer' and relatively easy to become mainstream, given their are no other alternatives.

Jonathan

 

[Farmer Piles]

I applied Prop Speed two winters ago and I have just completed my second season with it. Brilliant stuff. I have a 32ft mobo, single shaft drive and four blade bronze prop.
I had a mate help me and followed the detailed instructions. All very straight forward and simple to do. Attention to detail and getting everything prepped made it a relatively simple task. I used an almost worn out fine grade flap disk to polish the prop first.
I did the prop, P bracket and prop shaft - obviously leaving the shaft anode uncovered. I also did the twin bronze rudders but that was a mistake as the water flow past then is not enough to keep them clean of weed. I will be cleaning them up and on with A/F next year.
The prop and shaft stay completely clean of weed, they just have a few barnacles grow on them if I have not been out for a while but they soon wash off when underway. You can remove them from an awkward corner with the pad of your thumb. I have been down and checked and cleaned the rudders.
The other benefit is that it massively reduces electrolysis as the area of metal exposed to the water is hugely reduced. The shaft anode has done two seasons and has little signs of wear. I will replace it anyway this winter.
As you can tell, I really rate it. According to guys who work on the superyachts locally, they all use it.

 

[Sandy]

Never seen the need for coating a prop in anything.

Most boats that have some form of 'antifoul' on the prop get hauled out covered with some marine growth. My prop comes out pretty clean.

 

[Snowgoose-1]

Wasn't silicone AF a craze in about 1997?

PTFE possibly ?

 

[vyv_cox]

My account of many years' experience with Velox in Greece can be found here Propeller antifouling with Velox

 

[Farmer Piles]

I imagine a very similar product to Prop Speed?

 

[vyv_cox]

I imagine a very similar product to Prop Speed?

Propspeed say it is silicone based but their MSDS sheet says
Phosphoric Acid
-Butoxyethanol

Velox, MSDS sheet says
2-METHOXY-1-METHYLETHYL ACETATE and ZINC PIRYTHIONE
I understand that the zinc compound is used to treat some forms of dermatitis.

 

[Hoolie]

My account of many years' experience with Velox in Greece can be found here Propeller antifouling with Velox

We've found Velox very effective in slightly brackish water in the Western Med. Hardly any fouling after two or three years. No shedding of the antifoul after careful application, ie following the instructions to the letter! Previous experience with a polished bare prop was diabolical.

I haven't tried PropSpeed but being silicone product it does sound to be a one way decision!

 

[Neeves]

The other benefit is that it massively reduces electrolysis as the area of metal exposed to the water is hugely reduced. The shaft anode has done two seasons and has little signs of wear. I will replace it anyway this winter.
As you can tell, I really rate it. According to guys who work on the superyachts locally, they all use it.

The comment on electrolysis is interesting - I can understand why but its not mentioned prominently. Similarly the comment made of the superyachts is the same as here.

Jonathan

 

[Neeves]

I imagine a very similar product to Prop Speed?

Velox and Prop Speed are very, very different. The latter is a (relatively) soft coating, very similar to a silicone sealant, rubbery. Velox is like a normal hard AF or any hard conventional paint. They work differently and have different application instructions, and as you imply in your own usage - you need to follow the instructions.

Jonathan

 

[thinwater]

Propspeed say it is silicone based but their MSDS sheet says
Phosphoric Acid
-Butoxyethanol

Velox, MSDS sheet says
2-METHOXY-1-METHYLETHYL ACETATE and ZINC PIRYTHIONE
I understand that the zinc compound is used to treat some forms of dermatitis.

Actually, and SDS is ONLY a disclosure of chemicals and characteristics that affect worker safety. It is NOT an ingredient list or a spec sheet. Also, just as a mater of correctness, they have not been MSDSs in many years, since the US and EU came together on a global format. It is an SDS.

The self-etching primer contains 15% phosphoric acid in one part of the 2-part primer. The balance is solvents (including celosolve) and non-silicone resin.

The top coat SDS list only the hazardous ingredients (the resin would not require listing), which include solvents, one of which, reasonably, is a silane. The TDS (technical data sheet) identifies Propspeed as a silicone resin. I'm sure the details are a trade secret.