Don't trust Prop Shield

CliveG

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I fitted a new Bruntons 2 blade verifold prop at the beginning of the season.

prop-before_zps81163d01.jpg


Before fitting it I spent £37.53 on a tub of Prop Shield inc delivery.
I spent a sticky couple of hours coating the prop in this pink gunk.

I removed the prop last weekend after 6 months in use.

prop-after_zps9f6304a0.jpg


My old prop never had as much fouling with out any treatment.

Don't waste any money on this stuff.
 
hmm !

http://www.prop-shield.com/

"Prevents barnacles and hard growth"


I bet that somewhere in the instructions is something like this.

"Due to circumstances beyond our control, we cannot monitor the application of Boat Shield. So we cannot be held responsible for unusual growth conditions. Tough, matey "
 
I've been using Trilux (copper free) antifoul paint for the last few seasons on a Flexofold prop that is very similar to the Brunton's one in the photo. I've been seeing only the tiniest amount of baby barnacles near the blade roots and nothing at all like your pictures show. The Trilux lasts pretty well all season with some erosion on the leading edges as you'd expect but the marine growth gets eroded off there too so in the sheltered corners there is plenty of paint and no growth. The boat is kept on a semi-drying berth on the Hamble.
 
Soak it in brick/patio cleaner for an hour or so, all the krap will just fall off.
Be careful. The active ingredient in brick and patio cleaner is hydrochloric acid. This will remove fouling in seconds rather than hours, then start dissolving the zinc. I paint on brick acid diluted about 1:4 in water and wash it off as soon as the fizzing stops. If the prop goes pink, you've left it on too long.
 
Be careful. The active ingredient in brick and patio cleaner is hydrochloric acid. This will remove fouling in seconds rather than hours, then start dissolving the zinc. I paint on brick acid diluted about 1:4 in water and wash it off as soon as the fizzing stops. If the prop goes pink, you've left it on too long.

No zinc in a Varifold is there ?
 
Friend of mine used trilux on his folding prop - applied very carefully and many coats. Could hardly make the boat move a couple of weeks ago coming alongside to scrub off. Prop absolutely smothered in barnacles and not opening hardly at all. like a ball it was.
 
Be careful. The active ingredient in brick and patio cleaner is hydrochloric acid. This will remove fouling in seconds rather than hours, then start dissolving the zinc. I paint on brick acid diluted about 1:4 in water and wash it off as soon as the fizzing stops. If the prop goes pink, you've left it on too long.

I should add, the only time I have used the stuff was cleaning the prop at the start of the year whilst scrubbing between tides. The prop was soaking for about half an hour and still needed a lot of rubbing with scotch bright to remove the unwanted, the prop was left a dull dark grey/green so no attack on the metal. I would have thought a carefully monitored hour should allow the prop to discard all the crud with a gentle final rub with a scotchbright.
 
I've been using Trilux (copper free) antifoul paint for the last few seasons on a Flexofold prop that is very similar to the Brunton's one in the photo. I've been seeing only the tiniest amount of baby barnacles near the blade roots and nothing at all like your pictures show. The Trilux lasts pretty well all season with some erosion on the leading edges as you'd expect but the marine growth gets eroded off there too so in the sheltered corners there is plenty of paint and no growth. The boat is kept on a semi-drying berth on the Hamble.

I have found Trilux very good where it stays on the prop. The problem I had was that a lot of it just flaked off. What preparation and primer do you use?
 
IMG_2766.jpg


Velox prop antifouling after four months afloat in Greece. This taken immediately after lift out, before pressure washing. The photo was last year's. This year we used it again but only two coats instead of last year's four, which seemed to lead to the chipping that is visible. Very successful. I also used it on the P-bracket, which came out perfectly clean.
 
Saw a skipper of a Moody 33 burnishing his prop with fine graded wet-n-dry paper. Flawless bronze and like a mirror after four month afloat in the Ionion. He told me that the surface is kept so smooth that nothing can stick to it. No antifoul needed.
 
In the same waters I have had no success at all with that method. My prop shaft is also highly polished but is covered in tube worm by the end of the season.

BRIGHtT mirror polishing of our props always worked fine for us, but the exposed stainless shaft on our last boat we always antifouled or it did get fouled and yes with calcified tube worm, before that our boats did not have exposed shafts so no problem
 
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Thats encouraging. On the east coast (muddy waters!) fouling is a real issue and particularly of prop and sail drives - can Velox be bought in the Uk do you know. website does not show a distributor
 
Saw a skipper of a Moody 33 burnishing his prop with fine graded wet-n-dry paper. Flawless bronze and like a mirror after four month afloat in the Ionion. He told me that the surface is kept so smooth that nothing can stick to it. No antifoul needed.

+ 1 and here in the UK, the shiner the better, also polish with brasso before applying a liberal amount of grease. Never had a problem.
 
I dismantled and clean the prop back to bare metal and finish with a Scotchbrite rub. The prop is about 8 years old so it's not highly polished. I use 1 or 2 coats of 2-part Epoxy primer paint like Gelshield 2000 or Interlux and then give it 2 or 3 coats of Trilux.

Cheers,
C
 
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