White antifoul - time to change colour?

Lucky Duck

Lucky Duck

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I have generally used white antifoul as it easier to see which bit might benefit from a scrub, however this season I notice that white colours are in some cases being listed as a separate product with a suggestion of lesser performance;

https://international-yachtpaint.com/en/gb/boat-paint-products/antifouling/micron-350w

It appears to be the same Hempel Paints.

Might it be a good idea to switch to another colour come the time to put the new stuff on?

Maybe I should have stockpiled some more Micron Extra 2 :ambivalence:
 
As I understand it, the key active ingredient in antifouling is cuprous oxide (or copper (I) oxide if you prefer). This is red in colour. In order to produce a white antifouling, a lot of white inert pigment will need to be added in order to mask the red colour. It is therefore likely that white antifouling will contain less cuprous oxide, and therefore be less efficient.
 
Kwik Decision said:
As I understand it, the key active ingredient in antifouling is cuprous oxide (or copper (I) oxide if you prefer). This is red in colour. In order to produce a white antifouling, a lot of white inert pigment will need to be added in order to mask the red colour. It is therefore likely that white antifouling will contain less cuprous oxide, and therefore be less efficient.
Click to expand...

I believe that copper thiocyanate is often used as an alternative to Cu (1) oxide in white antifoul, as it is one of the few Cu compounds which is white.

I used to use a white A/F but changed to a darker colour, and I am sure that the white formulation is not as effective. However, when I asked a rep of one of the manufacturers at a boat show, they said that the colour made no difference.
 
KeithH said:
I believe that copper thiocyanate is often used as an alternative to Cu (1) oxide in white antifoul, as it is one of the few Cu compounds which is white.

I used to use a white A/F but changed to a darker colour, and I am sure that the white formulation is not as effective. However, when I asked a rep of one of the manufacturers at a boat show, they said that the colour made no difference.
Click to expand...

Cu2O though in Micron 350W according to the msds

When I last used white AF it contained TBT
 
Little Grebe said:
I have generally used white antifoul as it easier to see which bit might benefit from a scrub, however this season I notice that white colours are in some cases being listed as a separate product with a suggestion of lesser performance;

https://international-yachtpaint.com/en/gb/boat-paint-products/antifouling/micron-350w

It appears to be the same Hempel Paints.

Might it be a good idea to switch to another colour come the time to put the new stuff on?

Maybe I should have stockpiled some more Micron Extra 2 :ambivalence:
Click to expand...

It was probably the same with Micron Extra 2. I use black Micron, and find it works well. The data sheets for Micron 350 show that black has more zinc oxide than white, and that black is more dense (2.18 vs 1.92) which I reckon is a good indicator of potential performance.
 
I change the colour of my antifoul each year. Why? Because when you are painting it on it’s easier to see where you have been and where you may have missed.
Ast whit A/F I used ended up a sort of dirty grey so have since then stuck to the darker colours.
 
Don't guess.

The contents in the tin are defined somewhere (someone, somewhere in the EU demands it). The contents might even be defined on the tin. If white has less active ingredient it will be obvious. AF suppliers assure me it makes no difference.

We use red as helicopter pilots tell me its easier to spot (when inverted) :)

Jonathan
 
I use black, and have noticed that over the year, it turns green above the waterline.
 
Bobc said:
I use black, and have noticed that over the year, it turns green above the waterline.
Click to expand...

I use white, which also turns green above the waterline. This at least suggests the same ingredients at work.
I used the blue version of the same Micron on my previous boat, same berth, and have not noticed any difference. If it says on the tin the same active ingredients are used in the same proportion there is no reason to doubt that.
 
Neeves said:
Don't guess.

The contents in the tin are defined somewhere (someone, somewhere in the EU demands it). The contents might even be defined on the tin. If white has less active ingredient it will be obvious. AF suppliers assure me it makes no difference.
Click to expand...

Unfortunately, the contents are only very loosely defined, eg ">25% <50%", so it's not possible to compare with accuracy.
 
We have a mix, our Hull is coppercoated but the iron keel is not and currently white antifoul, we were also thinking of going darker (first season with the boat), is anybody aware of any restrictions to what we can apply to the keel with a copper coat hull? Not yet looked into it much myself but as there is a thread on antifoul running I hope you don’t mind the question.

Chris
 
For the future it can be checked.

When 'you' next AF find a neighbour using white (or another colour) and apply white and another colour of your choice of the identical formulation adjacent to each other in a location where you will not mind the patch - report back in 1 year and earn money, for your effort, by writing it up for PBO.

Jonathan
 
I have used black for at least the last 25 years. It is always the same paint but in a few of the years the hull was quite heavily fouled. I put it down to climatic aspects.

OTOH I understand that if you go ocean cruising you should avoid red, the reason being that the colour attracts whales which confuse them with squid.

Personally I think that that's far'fetched - but I wouldn't use red just in case...
 
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