Prop Speed primer replacement

[michael]

Hi All

I have been given some Prop Speed (PS) antifoul  but none of their primer - leftovers from a mates yacht. I have not been able to get the OEM primer as they will not sell it!!

Has anyone used any other primer with the PS top coat?

I have tried some "PA10" on my spare prop - out of the water - and then the PS top coat. It appears to adhere but until it in use in the water I will not know if it will last with use. I have been unable to find the composition of the PS primer, but from the look of it I think it is "Zinc Chromate". We used this stuff on aircraft alloys when riveting them together in the past. Not used now as it is "not good" for the user or environment. I can not find a supplier for it either.

So, have you used PS with a non OEM primer with success?

I will be on the slips from Monday 03Nov so will be cleaning the prop then.

Cheers

Michael N28 #24

PS. The cost of the slip at Greenwell Point is now:

Winch up        $255

Winch down   $255

Slip/day          $9.25/metre

Was $125 each way - now that is inflation for you!!!!

Am now going to Ulladulla:

Winch up       $45

Winch down   $25

Slip/day         $6.55/metre  (minimum $45/day)

Now that is better!!

Michael

[Les Fairwind]

Hi Michael

I understand that Propspeed has a very short shelf life, 6 weeks I hear.  Professionals at home will only do enough props at one time to empty the tin, rather than leave a tin opened and unused.  If it is older than that, I'd be inclined to bite the bullet and get it done professionally.

Here a bloke does a mobile service, is always using it so it doesn't go off.  He also polished and preps the prop, charges me about $100. Better than buying your own tin and have it go off on the shelf unused.

You can also take it to a propeller expert to do, but be careful who you choose.  A neighbour of mine did that, he got the prop back wrapped in gladwrap, as is usual, but when he unwrapped it, the Propspeed all came off on the gladwrap.  Not cured long enough, apparently

Good luck with it

Les

[Djarraluda]

Interesting discussion, because I have never used the stuff.

Hard racing copper was best in the Essex creeks back in Pommyland, then TBT worked well for years until banned.

Now I use Altex but for the prop, use a Hard anti foul and a layer of soft over the top.  New experiment this year as it was very highly recommended by the yard here

Re the actual discussion in hand though - there are application issues with many substances and the tried and tested mantra is always - do not mix the manufacturers.  Having said that, I prefer to look at the chemistry when I can get enough info.

Part of the problem with the old zinc chromate primer was that it formed a skin after too many hours and any subsequent layer peeled off.  I am slightly cautious at the use of the zinc chromate, which is an oil based product typically, and suspect it is more technically advanced than that.  I am only a mere mechanical engineer and need to consult a good chemical wallah for a chat.

As far as going-off in the pot though, I am curious as to the chemistry behind that if it still looked and behaved OK until wet.  Going-off in the pot is either a vapour loss, as in normal painting processes where the solvent evaporates, or it is a chemical reaction, as in a moisture sensitive poly where the atmospheric moisture is enough to set the base.

It actually sounds like the primer was left too long before the next coat was applied.

It will be good to source some proper data and review that but I fear that even the aerial safety data sheet will not be enough

[michael]

Just had a look at the MSDS and Tech Data sheets. The primer does contain zinc chromate, amongst other chemicals. The Clear/Top coat does contain some volatile agents, mainly made of Xylene and Methanol. The primary chemical appears to be Silane: a hydrocarbon containing tetravalent silicon instead of carbon. Basically it is a liquid silicone coating. This becomes very slippery when wet and makes it difficult for the fouling to adhere. As it does not poison/annoy  the fowling like copper the prop must me rotated/driven frequently to "spin off" the fouling. I do not believe that the short exposure to the air has degraded the PS top coat too much. It seems to have "set" on my spare prop OK.

Other info gleaned from their web page makes me believe that a good non-Ferris primer used in the same manner as the PS primer could work.

I will give it a try. As I can remove the prop in the water I will be able to remove it and fit the other prop if required in the months to come.

Cheers

Michael

On Wednesday, October 22, 2014 5:13:39 PM UTC+11, michael wrote:

[Reveries First Mate (Skipper)]

Another point to think about with prop speed. It has been recommended by the guys we use is to run your motor every 2 weeks for the best proformance. Great excuse to go sailing.
Bob.

[Graeme Lock]

Hmmm. If you ran your prop every two weeks you wouldn't have much growth on it anyway.

 

On this topic, I recently got an increase in speed while motoring after I ran the the engine in reverse for awhile. I was doing just over 5 knots flat out, and just idly wondering what might happen, shifted to neutral then gave it about 2000 rpm in reverse for a short while. Of course the boat slowed and slewed around a bit. Then when I resumed forward motion, it managed another 1/2 a knot with no change in wind, waves, course or revs.

 

I assumed the sudden change, and the addditional speed of water over the prop may have knocked some more stuff off the blades.

 

This was not an experiment supervised by scientists, and I offer it up with no claims to anything but that I did see what I saw.

 

Cheers, Graeme 

 

 

 

On 27 October 2014 11:16, Reveries First Mate (Skipper) <bob...@mountainandbush.com> wrote:

Another point to think about with prop speed. It has been recommended by the guys we use is to run your motor every 2 weeks for the best proformance. Great excuse to go sailing.
Bob.

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[C30 Stargazer]

Scientific...you'd need a 'double blind' trial and that takes a lot of rum.... The difference from a fouled bottom and prop and a clean one was about 3 knots on Stargazer. In fact at full revs clean, she is doing around 7 knots and is sinking at the stern (clearly past optimal hull speed) and the cockpit starts to fill.The American yachty mags are full of people using galmet type products on their props. Bruce

On Monday, October 27, 2014 6:05:42 PM UTC+11, lockie wrote:

Hmmm. If you ran your prop every two weeks you wouldn't have much growth on it anyway.

 

On this topic, I recently got an increase in speed while motoring after I ran the the engine in reverse for awhile. I was doing just over 5 knots flat out, and just idly wondering what might happen, shifted to neutral then gave it about 2000 rpm in reverse for a short while. Of course the boat slowed and slewed around a bit. Then when I resumed forward motion, it managed another 1/2 a knot with no change in wind, waves, course or revs.

 

I assumed the sudden change, and the addditional speed of water over the prop may have knocked some more stuff off the blades.

 

This was not an experiment supervised by scientists, and I offer it up with no claims to anything but that I did see what I saw.

 

Cheers, Graeme 

 

 

 

On 27 October 2014 11:16, Reveries First Mate (Skipper) <bob...@mountainandbush.com> wrote:

Another point to think about with prop speed. It has been recommended by the guys we use is to run your motor every 2 weeks for the best proformance. Great excuse to go sailing.
Bob.

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[Maeling]

Just went out and looked at my tin of automotive etch primer UN1263LFP not mention of what it is (I could look it up and did in Wiki "Paint-related materials including paint, lacquer, enamel, stain, shellac solutions, varnish, polish, liquid filler, and liquid lacquer base, or paint related material including paint thinning, drying, removing, or reducing compound" not much help.  Had a friend do his 35 footer last week in twopack pure copper (about $9k).  Was thinking of putting it on him for enough leftovers to do my prop - soon. Ulladulla sound like a good sail!

Geoff

O

[Les Fairwind]

Hi

Talking of sinking the stern when underway, my Duncanson does that too.  I understand when John Duncanson got the permission from Compass to change the hull to the Duncanson 29, he added some bustle at the stern to stop the tendency to dig the stern in under power.  Mine still does it, drops so far at WOT that the exhaust outlet in the transom goes underwater, not a good thing either, increases the back pressure on the motor.

But it would seem that digging the stern in under power, even with a horizontal prop shaft, is common with Compasses.

Regards

Les