Prop anti-fouling treatments-is it worth it?

I keep reading how copper bottom paint is bad on props and draws the zinc out of them weakening them. I was having no luck with bottom paint anyway. Falmouth harbor is so closed and stagnant it makes for quick growth and huge barnacles. My previous boat I did the same: Pettit underwater zinc, epoxy bottom paint, sandblasting and copper plating, wax. Nothing worked.

Yeah, everything in life is bad for you as many preach. Bottom paint alone did not work for me. Using the method I described worked and I continue to us it.

EDIT: If I remember after haul, I'll try to post pictures of what the metals look like....good or bad.

cappy208 said:

I keep reading how copper bottom paint is bad on props and draws the zinc out of them weakening them. I was having no luck with bottom paint anyway. Falmouth harbor is so closed and stagnant it makes for quick growth and huge barnacles. My previous boat I did the same: Pettit underwater zinc, epoxy bottom paint, sandblasting and copper plating, wax. Nothing worked.

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Cappy--

I returned to your post to comment on bottom paint and props. I looked into the materials used in props such as manganese bronze and also NiBrAl or nibral props. What I noticed is that in both materials the amount of zinc is small. Also the relative volts of copper to manganese bronze measured with Calomel half cells are almost the same ranging from -2.5 to about -3.8 as best I could read the chart.

That is a very small difference and I am doubtful any zinc depletion can happen. Nibral has a larger voltage difference but has a pitifully small amount of zinc.

Others may comment although my opinion is copper paint shouldn't be a cause for zinc depletion in props.

Copper plating? Gees, I though I was the jerk to spend $100-200 getting my props plated. Heck, it was worth giving it a shot.

Tom - can you tell me what size props you have on your 42 Navigator? Rob
Robjbecht@yahoo.com

28" I believe.

Does "completely waterproof" mean you can use it underwater?

yep, and it has 40' cord.

what_barnacles said:

yep, and it has 40' cord.

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CAn use it in the water and comes with a 40' cord. EXCITING

Most winter storage marinas are or have already put a stop to bottom scrapping. They are rightfully concerned about the environmental jack boots who will not hesitate to slap fines large enough to bankrupt most marinas. And all in the face of goodness.

Several years ago Fairhaven Shipyard was found guilty of allowing bottom wash to leach back into New Bedford's harbor. The guilty finding came with a $175,000 fine! Now really! Where does the stuff stuck to boat bottoms come from? And for that matter include thoughts to ablative bottom paint designed to be self cleaning.

Some do-gooder challenged the EPA about why the fine was soooo small....yeah, too small. They were told that a higher fine would have put the Shipyard out of business along with a complete layoff of their staff.

Not impressed

I can do it as quickly with a wide putty knife. This looks like nothing more than a multi tool with a flat blade.

Gordon

Gordon J said:

I can do it as quickly with a wide putty knife. This looks like nothing more than a multi tool with a flat blade.

Gordon

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You just keep on believing that.

Its every bit as amazing as they advertise. I have cut and scraped my knuckles enough to know when a tool does the job effortlessly and without me having to through that, it rocks.

Perhaps I never let my boat get as foul as the one shown in the video. Typically I have a few isolated barnacles and that is about it other than on the running gear.

Gordon

Has anyone used Prop Glop? I have a friend that says it works. A diver can apply every 6 months.

Prop Glop

Has anyone else used this Prop Glop?

We have used Prop Glop for nearly 2 years. So far we have not had a single barnacle. It was applied by a diver in the water in January 2016 Cocoa FL and again in March 2016 in Cocoa FL after we had cruised FL for two months. Hauled in Cambridge MD July of 2016 and prop was still clean, and it was recoated. Hauled boat in FL January 2017 prop was still clean and recoated it. Hauled in July of 2017 in New England. Prop was still clean and recoated. Hauled in September of 2017 in Solomons MD. Prop was still clean, was recoated. We had previously used zinc primer for a decade but often had barnacles, at least near the blade palm and the hub. This Prop Glop performance might seem impressive, but we put a lot of hours and miles on our boat, so the prop is turning a lot more than most. This year we have run the engine about 600 hours and travelled about 4500 nautical miles. The boat was in fresh water (Lake Monroe) until end of March, and again for the month of June in Lake Champlain.

So I'm not touting Prop Glop as a miracle cure, just saying that our propeller has been clean for whatever reason, since we started using it 2 years ago. In the meantime we have run 1220 hours and travelled over 8200 nautical miles without a barnacle. It costs $35 for a stick about the size of a deodorant stick. One stick does our 24" prop three times.

tadhana said:

So I'm not touting Prop Glop as a miracle cure, just saying that our propeller has been clean for whatever reason, since we started using it 2 years ago. In the meantime we have run 1220 hours and travelled over 8200 nautical miles without a barnacle. It costs $35 for a stick about the size of a deodorant stick. One stick does our 24" prop three times.

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So I’m not saying that Prop Glop hasn’t worked for you, but I think it is highly likely that because you used your boat over 600 hours per year probably has a lot more to do with your clean running gear than anything. Find something that works for those of us that only use our boats less than 100 and you would be onto something.

For years in SE Alaska I used ArmorAll on my prop. Worked quite well but the water is cold and there’s reduced sunlight. Didn’t try not coating at all while we were there.

Now at LaConner Wa Willy has been in the water for over a year. The last time I took her out she was sluggish at first but came up to normal clean speed and rpm after about 1/2 hr. This year she’s hardly been used. I’m anxious to swap props so when I do I may have more to report but at this point I think it’s very worth putting on.

Used cold galvanizing coating before and I think the ArmorAll is more effective. I’m wondering if I should use the cold gal as a primer. May get a bit more AAll on .. more may stay on too. Not tried though.

Pic is w cold gal.

fstbttms said:

If the opinion of a hull cleaner with 18+ years of experience means anything; PropSpeed works well but is expensive, short-lived and difficult to apply. Pettit Zinc Barnacle Barrier also works well, is inexpensive and very easy to apply. Lasts as long as PropSpeed, IMHO. I don't find that PropSpeed has any advantage over the Pettit product that even comes close to justifying the expense. That's my $.02.

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I agree with using Pettit and also Pacifica I've used both and have not been disappointed

Ok. Here’s my test of Velox. I coated just the blades. Having just had the prop trued and cleaned at the shop last spring they put on an epoxy coat around the hub. I decided to leave the epoxy and just did the blades.
. This is the blades, with almost no fuzz or growth. I went diving at end of August and there were three barnacles on the Velox. The hub was encrusted.
This was after haul out. The hub grew barnacles again. But the prop was relatively clean.

This is on 38 hours running this summer around Cape Cod.

The pint of Etch and pint of Velox Paint was around $150. Planning on wire wheeling and sanding the entire blade down and doing the whole thing in Velox next spring. The pints are not quite half gone. So should make 2 coats. I did 3 last time. It says Velox is for all underwater metals. I may buy another set of pints and do the steel rudder as well.

So-Cal waters have a lot of critters, especially in the summer. We are at 3 week intervals in the summer, and 4-5 the rest of the year.


Anyone use the spray on "Barnacle Blocker"?

Tom.B said:

So I’m not saying that Prop Glop hasn’t worked for you, but I think it is highly likely that because you used your boat over 600 hours per year probably has a lot more to do with your clean running gear than anything. Find something that works for those of us that only use our boats less than 100 and you would be onto something.

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I agree with you, that the prop has turned about 30 million revs per year and and that could account for the lack of barnacles. That being said, the inventors of Prop Glop invented it for boats which sit a lot. So our own application is suboptimal according to the manufacturer. At $35 for a stick, it might be worth giving it a try. BTW if you apply it in the water, it is recommended that you wear a full wet suit. Apparently it burns if you get it on your skin. Also, it takes a bit of practice to get a coat on the prop thoroughly and evenly. I do not have any involvement with the company. A diver in FL recommended it. I'm just reporting on our observations. YMMV.

Fletcher,
I have used Pettit “Barnacle Buster” and found it worked somewhat.

But you may actually have a different product called Barnacle Blocker.
I posted in the event you got the name wrong.

FYI if you look carefully at the contents on a can of Pettit Barnacle Buster, and then at a can of Rustoleum cold galvanizing, you will notice two things. First of all the ingredients are exactly the same. Second of all, the prices are very different. Many east coast boatyards are using zinc spray. Most are using the Rustoleum.

I can’t seem to edit my earlier post. The Velox treatment was $96.00 for the half pints of etch and bottom paint.

tadhana said:

FYI if you look carefully at the contents on a can of Pettit Barnacle Buster, and then at a can of Rustoleum cold galvanizing, you will notice two things. First of all the ingredients are exactly the same. Second of all, the prices are very different. Many east coast boatyards are using zinc spray. Most are using the Rustoleum.

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A couple questions for folks who have used this, or similar coatings:

There are various versions of this...Is this the correct stuff?
Ok to use on both the shaft and prop?
Are 1 to 2 cans enough to spray a prop and shaft?
One coat sufficient?
Drying time allow splash after a few hours?

Thanks, Fletch.

cappy208 said:

I keep reading how copper bottom paint is bad on props and draws the zinc out of them weakening them. .

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So don't put anti foul directly on prop.
Our prop, nozzle and rudder, all bronze, gets a layer of jotamastic first, then anti foul.
Apparently that's how a lot of the working trawlers do it.
18mths since last slip, most of its pretty clean down there, speed/rpm has not changed even though there were gardens growing around our numerous anodes.

I have done bare bronze. By August it’s barely recognizable as a prop. Looks more like a multi armed barnacle club. After trying many different ideas, The Velox is the best thing I have found that left the prop almost completely free of growth. A VERY small amount of slime. But only 3 small barnacles. And they fell off with just a light brush. The uncoated part was terrible. My through hulls are all relatively growth free (and ablative coated as well).

Fletcher500 said:

A couple questions for folks who have used this, or similar coatings:

There are various versions of this...Is this the correct stuff?
Ok to use on both the shaft and prop?
Are 1 to 2 cans enough to spray a prop and shaft?
One coat sufficient?
Drying time allow splash after a few hours?

Thanks, Fletch.

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Looks to be right to me. 93% zinc. One can should be enough. one can does my gear about 3 haul outs with about 4 coats at each haulout. Several thin coats work best. It is by far the best to let it dry 8 hours before splash, but I have applied it as the travelift was rolling.

tadhana said:

Looks to be right to me. 93% zinc. One can should be enough. one can does my gear about 3 haul outs with about 4 coats at each haulout. Several thin coats work best. It is by far the best to let it dry 8 hours before splash, but I have applied it as the travelift was rolling.

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Thanks Todd. This will be a quick haul, but if if there is time, I am hoping to get a few coats on.