Prop anti-fouling treatments-is it worth it?

[Fletcher500]

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"?

[tadhana]

Originally Posted by Tom.B

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. :-)

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.

[Nomad Willy]

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.

[tadhana]

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.

[cappy208]

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

[Fletcher500]

Originally Posted by tadhana

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.

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.

[Simi 60]

Originally Posted by cappy208

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

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.

[cappy208]

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).

[tadhana]

Originally Posted by Fletcher500

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.

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.

[Fletcher500]

Originally Posted by tadhana

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.

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

[Tom.B]

Opinions on this subject are all over the place. We just came down from a haul and we used the expensive version on galvanizing spray by Petit (directly on the prop). We were told by our diver to use 10 coats of the cheap stuff from Lowe's that you are linking to, but I just didn't trust it (for no particular reason). I followed the directions on the can and ended up with about five coats. One can did slightly over one coat on our two 28" props.

We don't know the results yet, but I will post them when we have them. TBH, part of our problem was lack of use in our long visit to Morehead City. We sat for three months in a high-growth environment and didn't know our diver wasn't servicing our account. Anyway, everyone we talk to about the subject agrees that using the boat (and we are a go-fast planing motoryacht) is the best preventive action we can take.

[seabum]

I cannot seem to determine from all these assorted responses if this Zinc spray-on material can be used on the shafts and props both?

From other boating forums it sounds as if this spray zinc does a good job keeping the barnies away without breaking the boating bank, but still am not sure if I should only use it on the brass props or if I can also apply it to the struts and shafts.

[Tom.B]

It can be put on any underwater metal. I only put it on props and nothing else. The props I wanted clean for placement and movement of anodes as needed. On the struts, rudders and strainers I just used regular bottom paint because stripping them back to bare metal would have been a huge PITA. :-)

[meridian]

I just pulled after 12 months of cruising from FL to Great Lakes with no cleaning during that time. I had used Rust-oleum on the props, struts, and shafts. There were no barnacles.

[Fletcher500]

Originally Posted by meridian

I just pulled after 12 months of cruising from FL to Great Lakes with no cleaning during that time. I had used Rust-oleum on the props, struts, and shafts. There were no barnacles. Attachment 71341

Impressive. How many coats did you use?

Side Note: I realize there are a lot of variables involved, usage being a key one along with the area, season, diver cleaning skills, etc. There are a lot of products out there, some being much more $ than others. I am starting to wonder how much more effective they are than a can of $10 spray paint based on some of these reports.

[Heron]

1.5 years on the Rustoleum stuff and still barnacle free. Shot everything but the zinc. My mistake was not doing the Bow thruster blades and transmission....Which is now very encrusted and barely thrusts...Lesson learned!

[Simi 60]

91% in oz for the dymark product available at the big hardware.
https://www.bunnings.com.au/dy-mark-...c-gal_p1580554

Wonder how it would go on the aluminium dinghy and outboard?
Is it likely to have dissimilar metal issues?

Add: I have large zinc anodes on the dinghy and o/b now so I guess not

[meridian]

There was a minimum of 3 coats could have been twice as many

[Simi 60]

Originally Posted by Simi 60

91% in oz for the dymark product available at the big hardware.
https://www.bunnings.com.au/dy-mark-...c-gal_p1580554

Wonder how it would go on the aluminium dinghy and outboard?
Is it likely to have dissimilar metal issues?

Add: I have large zinc anodes on the dinghy and o/b now so I guess not

Just looked at the 2 cans I have onboard.
Big numbers on the front say 98.5% pure zinc

I linked to the wrong product.
The higher zinc content is cheaper
https://www.bunnings.com.au/dy-mark-...-zinc_p1580764