Rustoleum Cold Galvanizing Compound

mintregila

mintregila

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In the spring, we had a topic about this stuff as a coating for running gear. I sprayed my props, rudders, struts and shafts with it using slightly over 1 can.

Pulled the boat last week to change out my props for performance issues.

No a barnacle or any other growth on any of the gear. At $5/can this can't be beat.
 
Yep. I used it too. Same result. Gonna use it this year on trim tabs as well. I use trilux on ips.
 
I used it on my outboard brackets that are partially submerged. Some slime and a little grass that brushes off. As good as if not better performance than the expensive stuff.
 
I should add that I extended the anchor chain on my boat using one of those peened links years ago (over-sized, of course). It used to be I had to replace it ever few years as it would start to rust. The last time I put this Rustoleum product on the link and it has remained rust free. The other galvanized links I accidentally hit with overspray look great too :-)
 
Wish I could report similar results. My struts, rudders, shafts and props were FULL of barnacles!!
 
walshie: was the stuff still there or had it been etched away? Different electrical conditions in different areas could account for differences in result.
Once the zinc is gone there must be some paint base left but it would not perform the same.
 
We just finished our third season using the Rustoleum cold zinc spray. Most of the time we are in Long Island sound with one or two shorter trips into brackish or fresh water for few days only. We use it on the props and shafts only but it seems to work better than anything else we have tried over many years past. During the season when I dive on the boat there is very little growth and what is there is soft and mostly comes off during use. At haul out there were a few hard barnacles near the props center but very little hard growth anywhere else - soft growth was gone as we just had a decent trip to haul out.
Staying with this spray now based upon performance primarily but the cost is so low as well.
 
Bruce
Boat is in NY pretty far up a creek that tends to be a growth and barnacle habitat based on my experience the lastfew years there.
 
I was hoping you were having that kind of success in FL. Your method is way cheaper than mine.
 
I just recently used the Rustoleum Cold Galvanizing stuff on the boat lift bunk brackets in FL. I had to move the brackets from where the previous owner had them set. Moving them left some scratched up areas, and exposed a slightly rusted area underneath where the brackets had been. The previous owner swore by the stuff, and he said he coated the lift bunk brackets with it once a year. The lift generally stays in the up position, and obviously won't replicate use on running gear, ... but it does seem to do a good job for the lift.
 
I Have similar good results with Interlux Primacon although I apply bottom paint over the Primacon. Although I never had problems when I was in a slip up river, serious barnacle problems appeared when I moved to a lagoon close to the bay.
The theory is simple, one needs an electrical isolation between the bronze underwater gear and the copper paint and that is what Primacon is designed to provide.The copper will leach out of the bottom paint applied direct over the bronze.
Primacon is more expensive so if the cold zinc works for you that is much cheaper.
Do you apply bottom paint over the zinc coat?
It may depend on the water including water temperature where the boat is moored.
 
"I Have similar good results with Interlux Primacon although I apply bottom paint over the Primacon."

That is the same thing we did for many years on Long Island sound with pretty good results. Three to 4 coats of the primocon followed by a few coats of a good ablative paint worked well.
But not only the cost but the amount of work to prep and make all of those coats each year was quite a pain. It was quite a job to remove the old stuff or at least the spots it had failed to make ready for touchup or replacement coats the new year.
That combined with the time and weather (dry plus 55+) required for the new coats each year was more of an issue than the much higher price.
Now we just remove the balance of the spayed cold zinc spray (usually with a floor scrubber pad) and re-spray with 2 coats of the cold zinc spray at maybe $15 for two cans - no overcoats at all just the zinc spray.
Done....
 
Smitty,
I never removed any of the old coats each year, and found the effectiveness increased each year.
Do the instructions require removal every year?
I applied the Primacon over last years bottom paint just after the high pressure wash and repainted with bottom paint.
 
I was only removing the coatings on the props and shafts not the struts and rudders.
To keep the props and shafts relatively smooth it was more or less required as they wore and became 'patchy' each season.
Now the shafts and props just get the cold galvanizing zinc paint each year as it works , is light, and easy to clean and recoat.

On the struts, rudders and sea water pickups I will just add bottom paint if/as needed.
If the paint was removed down to the metal I will touch up with more coats of Primocon only in those areas and then add bottom paint.
I would not suggest adding primers over any bottom paints especially ablative paints as they will crack and sheet off earlier than expected.
 
Smitty,
Thanks for your experience.
I have added Primacon over ablative paint w/o any issues and have touched up as well in and an attempt to get as smooth as possible surface.
I don't run a lot at high ROM so maybe I have not seen a need for smooth prop surface.
I have friends who use the zinc spray paint successfully in less aggressive environments than I moor at, but I am reluctant to risk a labor intensive or costly clean up versus spending $30 + for a can of Primacon.
With little problems for years, I had to spend hours on a metal clean up when I first moved to more aggressive environments close to the bay with no dilution with fresh water from a river or stream feeding the site.
Every one needs to make a decision based on the location where they moor their boats and their experience as to what works. Maybe the zinc spray paint would also work for me but I won't risk based on the cost of Primacon that works for me.
 
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