Dear fellows,
After almost two years of controlled experiments, I am happy to report that the antifouling samples are finally ready for comparison, and I will be publishing full photographs and results here shortly.
Across this project, I created 192 experimental samples using the following coatings:
Juton Altex 5
Altex 5 Plus
Seahawks
International Micron 2
Vivid Petite
Two custom mixes based on Teflon and Titanium Oxide
Despite the large number of initial variants, only 4 samples survived to the finals.
The Winning Formula
The standout and likely best performer was:
Vivid Petite + 20% copper powder + 10% zinc pyrithione (ZnPT)
2 kg copper powder per 10 litres 1 litre of professional anti-mould additive
($135/L in paint shops versus $30 for 75 mL at Bunnings)
Three Budget Alternatives
Based on Altex 5 Plus, modified with:
20% anti-mould additive 10% zinc pyrithione (ZnPT) Copper sulphate at 5%, 10%, and 20% dissolved same day in purified water
Results
Zero slime on all four after 12 months By 17 Feb 2026, they will reach 24 months submerged Single coats only Static immersion, not moved Each has a control sample for comparison
After 18 months, these samples had not a gram of slime, while freshly antifouled boats in the bay looked terrible after a single year.
Environmental Reality Nothing Harmful Here
Copper
Naturally abundant in seawater. Every marine organism evolved with it. Nothing unnatural was added.
Zinc (ZnPT)
In every sunscreen. People swim, jump in the water tonnes of zinc enter oceans every summer. Far smaller impact here.
Anti-mould additive
Biodegrades just like antibiotics do through wastewater. Microbes break them down. The ocean breaks them down. Same pathways, same story.
So all three:
Copper, Zinc and Anti-mould additives
.are far less intrusive than what's already entering the oceans every single day from normal human coastal life.
Why I chose these blends
I could push the chemistry further, but that would step over my line of environmental responsibility.
This mix is safe, balanced, and still triples the effectiveness of mainstream paints.
Paint Purchasing Tip (Massive Savings)
If you want to save real money and I mean real money buy your paints directly from Altex in Smithfield (Sydney area).
10 litres will cost under $500 while Whitworths will charge around $800 for exactly the same volume
That's $300 saved straight away.
Same story with Vivid Petite huge savings. If you have to get in the car and drive there do it. You will thank yourself. Petite is better paint but price is as well.
And I want to make this absolutely clear:
I do not have any financial gain from saying this. I am doing this purely to help fellow sailors save money, avoid waste, and enjoy better performing antifouling without being ripped off by divers and marine shops.
We look after each other that's the whole point of this post. Not promotion. Not advertising. Just genuine help from one sailor to another.
Next Sunday
I will:
Retrieve the samples Photograph them properly Photograph their control references Publish everything here
It's going to be one of the more eye-opening antifouling comparisons this forum has seen.
Vivid petite plus 10% copper and 10% antimould paint additive ( left) vs vivid petite no copper and 5% antimould paint additive in the middle and 10% antimould paint additive far right.
The winner is vivid petite with 20% copper powder and 20% antimould paint additive mould paint additive. Not a single slime after 21 months. Impressive.
Altex 5 plus with 10% copper sulphate (1 kg copper suphate in 400 ml boiling water ) 5% zinc pyrotite and 20%antimould paint additive won among all Altex 5 plus mixtures. Impressive . No slime at all . Not even few cm around if you have a good look at the sample ( the smallest blue).
I hope this helps. Amazing sample as after 19 months
Top sample is vivid with only copper powder added, performed better than original vivid petite but still some slime. The winner is vivid plus copper plus antimould paint additive. Cheers
Obviously a sublime and sustained effort by you here Dr Serb, great thanks. At 2.22m draft we are using Vivid Petite down at Kogarah Bay and will assess those additives for next slipping August 2026. As long as this next slipping is worth it going forward in relation to depths in KB, the river under the Captain Cook Bridge out to Botany Bay and BB itself. So these depths not silting up anymore and reducing so alarmingly. Evidence off Ramsgate, Quibray for a long way out as always. KB model yacht sailors must be concerned. Dredging seems to have worked at Swansea and maybe it will at Port Hacking.........maybe BB, CR and KB are coming soon. Of course the sailable area of KB thieved (with all authorities "approval") by a motor boat club recently will never be recovered.
The above text re dredging etc is probably thread drift - apologies - others and Toph maybe will advise. The concept of sailable water area thieving obviously has been going on for a long time - including a while back in Auckland and a lot more recently in the harbour - potentially at Woolwich and Gladesville. I have lost track of both - the former narrows the channel to Cockatoo Island, the latter the channel under the Gladesville Bridge with the rock shelf on the north side of the bridge unmarked.
That's a mammoth effort Serb, well done to you. I love seeing peeps do their own research, so 12 out of 10 for that good sir!
Don't want to put a dent in this in any way, but have you checked with Australian Pesticides and Veterinary Medicines Authority (APVMA) regards legality? My antifoul got defected by APVMA when I imported the boat, even though it was a well known French brand.
I dont care if it is or isn't, but it's important to know. That way if someone opts to try it out and you've informed them, there is no recourse on you ('no good deed goes unpunished' sort of thing) .
Thank you very much for the effort and in sharing it. I look forward to reading more about it!
Gday Sir, did you dissolve the additives in how much purified water? Why not add the powders direct to the antifoul? Based on Altex 5 Plus, modified with:
20% anti-mould additive 10% zinc pyrithione (ZnPT) Copper sulphate at 5%, 10%, and 20% dissolved same day in purified water?
You cannot add copper suphate direct into Altex 5 plus it will not dissolve. CuSo4 is water soluble.
copper suphate goes in the same day the rest can go few weeks . Mix it well. 600 ml of purified water on 1 kg of cuso4
Please don't anyone self mix anti foul, it is harmless at test scale but it's pretty easy to imagine with what ? 20,000 boats ? in Sydney harbour, ?maybe 30% ? anti fouled that it might not scale well.
Point being that there are people who give this more than a cursory glance and then set regulations according to data and science.
The environmental claims of safety are pretty much false, dissolved copper ions are toxic to many marine organisms at microgram-per-litre[/i] concentrations.
ZnPt is not necessarily safe, has partial ban in EU?
pubmed.ncbi.nlm.nih.gov/38713926/
I could go on but my 10 minutes of research time is up for this topic without payment : p
Nahh, I reckon we are all good. Do some back of envelope calculations of water in Sydney Harbour. About 2/3rds of the harbour gets exchanged every day, that is about 750 million cubic metres. One cubic metre is 1000 litres. So that is 750 billion litres per day getting flushed in and out. So let's say 100 Seabreezers add 1kg each to their antifoul that lasts two years - that is 100kg extra ablated over 365 x 2 days = 730 days. Each day the tidal exchange has to carry the extra load of 100/730 which is about 0.13kg of dissolved copper in 750 000 000 litres. I teach Chemistry and I don't think we have a unit for that tiny amount - spiders dick doesn't even come close.
Dilution is the solution to pollution. There will be much more copper being flushed down drains, spilt down driveways, eroded from copper pipes and being sold as a drain cleaner and soil conditioner from Bunnings. www.bunnings.com.au/manutec-500g-copper-sulphate-soluble_p2961523?store=7380&gclsrc=aw.ds&gad_source=1&gad_campaignid=23022021534&gbraid=0AAAAADtbEB_6Bn2e1jpqxQOdTSeE5fRZe&gclid=Cj0KCQiAo4TKBhDRARIsAGW29bciqCBT7wyplceUK4vaQLAsy3m1j3ZbZI5nbs4E1kJH5eVqaufay30aAniHEALw_wcB
We all have an impact - what gets my goat is when people who drive cars, fly in planes, flush their dunnies, get pest people in, wash paint brushes in water, buy industrial products, get on public transport and basically produce pollution, then look at boats and go "They are pooing in the water stop them!" So most of the time we are fine - which is why we can still poo in the water, but every now and then the word chemical gets used and people freeze. I like to get the Chem kids to laugh at things like "Chemical free" which means there is nothing in it. Even water is a chemical. Some simple maths shows Serb is fine in a nice harbour like Sydney.
Got it wrong - the correct maths is
0.13kg of dissolved copper in 750 000 000 000litres.This means 1.7 x 10-13kg parts per litre or 1.7 x 10-10g/L if ALL the copper from the paint is released (which it isn't). Also I am just using one tide a day when we now there are two so my calcs are twice as high as they will be really.
The most sensitive invertebrates during the most sensitive time of development is about 2 micrograms/litre. Fish can handle hundreds of times more copper. Also the copper has to be in complex forms to be absorbed properly (a thing called a ligand). Serbs stuff is metallic which is much less absorbable. So 1.7 is about 2. If we did what Serb says we would at most pollute the harbour an extra 2 x 10-10 gl/l. And the MOST sensitive animals at their most sensitive time is affected by 2 x 10-6 g/l. So even if 100 seabreezers did what Serb said, they would make the water one ten thousandth more toxic (Really 5 one hundred thousandths). It is not going to do anything. I think anyone who wants to is fine to go ahead and use Serbs recipe. Just don't tell a bureaucrat.
Yes, you are correct, I did a basic calc using static water volume and 50% of all boats (best guess I could find of 20,000) doing it got us to the lower end of the order of magnitude where negative effects could occur. So my guesstimations were a couple of orders of magnitude higher.
Totally agree with we all have an impact, I got triggered to check after recently reading about the build up of rat poisons in raptors and owls, the goal can and IMO should be to minimise the negative.
Note that while this may be affected by many other factors including temp and location there have been studies that show beyond a certain point more copper can result in less effective anti foul.
Lagerstr?m et al., 2020 - "Antifouling paints leach copper in excess - study of metal release rates and efficacy along a salinity gradient".
