Prop anti-fouling treatments-is it worth it?

[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]

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. View 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-400g-zinc-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]

91% in oz for the dymark product available at the big hardware.
https://www.bunnings.com.au/dy-mark-400g-zinc-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-400g-silver-zinc_p1580764