zinc chromate follow up almost 2 years

[lipets]

I painted my running gear in July 2019 with the spray on zinc chromate

Not from Pettit $25 but from Lowes or Home depot for $7 used 6 cans





No anti-fouling paint over it.




Diver said yesterday all still looked good.




In fact it's his first choice to recommend to others.

He offers to pull props spray and replace to many of his clients.

 

[Chrisjs]

Interesting! I tried zinc paint (industrial grade - thick) on my props and found it disappointingly ineffective. That was the "cold galvanizing" type paint. You are using zinc chromate, typically applied as primer. It appears to work quite differently because of the chromate component.

 

[Russell Clifton]

Not seeing zinc chromate in a spray can on the internet at Lowes or Home Depot. Any other information on the product you used? Thanks.

 

[CaptTom]

Thanks for updating!!!

I was about to buy a few cans of the expensive stuff. I'd try the cheap option based on your experience.

Is this the "self-etching primer" or is there something specific I should be looking for?

 

[lipets]

I'll try and find one of the cans, but it was by rustoleum I'm pretty sure

 

[Woodland Hills]

Just be very careful:

Recent studies have shown that not only is zinc chromate highly toxic, it is also a carcinogen.[17] Exposure to zinc chromate can cause tissue ulceration and cancer.[1][3] A study published in the British Journal of Industrial Medicine showed a significant correlation between the use of zinc chromate and lead chromate in factories and the number of cases in lung cancer experienced by the workers.[18] Because of its toxicity the use of zinc chromate has greatly diminished in recent years.

From Wikipedia

 

[Cigatoo]

https://www.zrcworldwide.com/

https://www.amazon.com/ZRC-Galvilit...id=1616161986&sprefix=Zrc,aps,256&sr=8-3&th=1

 

[fgarriso]

We did our boat's running gear with it three years ago. On the last haul-out 2020 every thing was still clean like we had just done it. Ours was the COLD GALV spray.

 

[Pocoron]

Zinc chromate is used extensively in the aviation industry as an aluminum primer. It chemically bonds to aluminum.

https://www.amazon.com/MOELLER-MFG-COMPANY-INC-CHROMATE/dp/B000N8LR24

 

[jimdavi]

I’m pretty sure aviation switched to FR primer due to environmental issues with zinc chromatic.

 

[friz]

. ......From Wikipedia

Well that is hardly authoritative. I wonder if there are warnings on the can as to toxicity? How about warnings from California? They seem to have problems with most consumer products.

 

[High Wire]

Our workshop back 45 years ago was half paint spray “booth” for zinc chromate primer for Navy parts. The booth was just canvas tye wrapped to the roof trusses. Everything had yellow overspray on it.

 

[Woodland Hills]

Well that is hardly authoritative. I wonder if there are warnings on the can as to toxicity? How about warnings from California? They seem to have problems with most consumer products.

I don’t know if California has banned it yet, but thirty years ago we replaced it with FR primer at Edwards Air Force Base.

So what is not authoritative about the Wikipedia article? Did you read it and the numbered citations and footnotes? If not, why not? If so what do you dispute?

 

[Pocoron]

Link to the Safety Data Sheet (SDS) pdf document related to the product I pointed to above for anyone interested:


https://www.google.com/url?sa=t&rct...TE-GREEN.pdf&usg=AOvVaw31Szga5MeiuC77C88CRPJX


No major red flags - use PPE.

 

[psneeld]

After 4 seasons in NJ with trips to FL and back, Zinc primer/cold galvanizing did nothing for me or the boats around me.


So I started just using bottom paint and it worked much better. The galvanizing/primer did work as a primer, but Interlux interprotect2000 probably would have been better.

 

[lipets]

my guess is the prep before spraying had an issue or you didn't build a thich enough coating

 

[psneeld]

my guess is the prep before spraying had an issue or you didn't build a thich enough coating

Nope, my coatings were thick (more than a can on a single prop and rudder) and seemingly perfect after I pressure washed all the growth off, but it wasn't zinc chromate....


For all I know that may work because it is so toxic.


But regular zinc primer or cold galvanizing seems to work occasionally for people and not at all for others.


Seems to be a lot like the cayenne pepper in the bottom paint debate...not solid answer.


Some of the biggest factors with fouling is where kept and use and speed of the boat.

 

[lwarden]

To my knowledge Rustoleum doesn't make a zinc chromate primer, but they do make cold galvanizing spray. Very different animals. I usually have to search hard to find zinc chromate, and lately I can't get it locally any more. Tempo made it and Moeller and it was sold via West Marine and other chandleries.
I've never heard of zinc chromate being used on running gear before.

 

[Chrisjs]

https://mavikmarine.com/marpro-zinc-chromate-primer-green-5605-dm6-5605.html?gclid=Cj0KCQjwl9GCBhDvARIsAFunhslpW_j4XNg6HEH99x-TA9AGbLgCQ0ogDR5uYcSWf_fS-i-1cGRZwh4aAiSGEALw_wcB

 

[lipets]

Ok my error not chromate
Rust-Oleum 7585838 Professional Cold Galvanizing Compound Spray Paint,

20-Ounce

From HD $6 a can

 

[Brooksie]

Just be very careful:

Recent studies have shown that not only is zinc chromate highly toxic, it is also a carcinogen.[17] Exposure to zinc chromate can cause tissue ulceration and cancer.[1][3] A study published in the British Journal of Industrial Medicine showed a significant correlation between the use of zinc chromate and lead chromate in factories and the number of cases in lung cancer experienced by the workers.[18] Because of its toxicity the use of zinc chromate has greatly diminished in recent years.

From Wikipedia

That's what I thought. Green primer pretending to be Zinc chromate perhaps?

 

[lipets]

You must use a respirator and other protective gear with many marine products

 

[Capt.Will]

lipets We did our prop two years ago this April and its still clean ,very happy,
with this product.
Will Stay safe

 

[High Wire]

We used the same stuff. Went on beautiful but 6 months later had 1/2" thick barnacle growth. This picture is after power washing.

 

[Madhatter53]

I’ve been using the rustoleum for maybe 6yrs and have had decent results. Good prep and a good coating might help. I’ll be doing this and my zincs tomorrow then in a few weeks a fresh coat of bottom paint before I get splashed. Archie you might want to back that shaft zinc a bit more from your cutlass.

 

[psneeld]

We used the same stuff. Went on beautiful but 6 months later had 1/2" thick barnacle growth. This picture is after power washing.

Yep, mixed results with the stuff. Looks better than mine but that again is a faster more frequently used boat.

 

[kapnd]

Ok my error not chromate
Rust-Oleum 7585838 Professional Cold Galvanizing Compound Spray Paint,

20-Ounce

From HD $6 a can

Dang!
You had me all fired up, I just found a gallon of zinc chromate in my shop.
Maybe I can use it to get rid of roaches...

 

[SteveK]

so, this stuff?

93% pure Zinc
Recommended for sheet metal, gutters, chain link fencing, spot welds and iron work
No top coat required
No need to prime
Not for use over previously painted or rusted metal

 

[lipets]

yes that's the paint, just be sure the metal is very clean, wire wheel or sandpaper etc

 

[SteveK]

Here is the stuff on my shafts and props.
Spring haul out soon.