ritchyp
Member
Shes a 36 footer with 2m draft long fin keel & 3.6m beam. Gonna be a lot of work. Ill be spending the weekend down on her in the yard so I will try out a few suggestions and see which works for me.
How many coats of antifouling paint
- Thread starter ritchyp
- Start date
Refueler
Well-known member
OK ... 38ft Cruiser Racer - so not a small area to sort !! She lifted out and was not so bad - but like OP - she had rough areas where previous A/F was creating ridges .. these in fact HELP Barnies attach as well as causing drag and loss of speed ... OK - not a great loss - but for me 1/4kt is enough !
Some life had attached where I think 'biological' matter may have a factor in it ??
And of course prop and shaft !
I paid the yard to sort .... I/m too old to do this sort of thing now .. and anyway - they have the materials saving me having to buy etc.
They orbital sanded the hull back to Gel Coat ... and a beautiful job done ... smooth as babys bum ... they then applied 2 coats of epoxy primer followed by 2 coats of high copper content VCTar.
When we lifted at end of season ... she was still smooth apart from again - speed logs and outlets ...
Contrary to some above - if you can take all old off .. then do it - instead of just adding more on top. As to which A/F to use ... for anything other than racing - then self eroding is my advice ... why use hard racing ??
2 coats on top of 2 coats of primer... is usual ... more if you can.
Some life had attached where I think 'biological' matter may have a factor in it ??
And of course prop and shaft !
I paid the yard to sort .... I/m too old to do this sort of thing now .. and anyway - they have the materials saving me having to buy etc.
They orbital sanded the hull back to Gel Coat ... and a beautiful job done ... smooth as babys bum ... they then applied 2 coats of epoxy primer followed by 2 coats of high copper content VCTar.
When we lifted at end of season ... she was still smooth apart from again - speed logs and outlets ...
Contrary to some above - if you can take all old off .. then do it - instead of just adding more on top. As to which A/F to use ... for anything other than racing - then self eroding is my advice ... why use hard racing ??
2 coats on top of 2 coats of primer... is usual ... more if you can.
Momac
Well-known member
Next time I am going to try a non toxic antifoul.
rogerthebodger
Well-known member
Nigel, can you give me a reference to were you got high copper content VCTar you refer to in post #22
I have not seen any reference to high copper content VCTar.
I use epoxy tar on the underside of my steel boat
I have not seen any reference to high copper content VCTar.
I use epoxy tar on the underside of my steel boat
penberth3
Well-known member
Good idea, but all sanding dusts are harmful, some worse than others
Refueler
Well-known member
Sadly no as it was supplied by the yard ... all I got was a quick look at the tins ..
The yard said it was high copper content and reason for the near black colour.
ritchyp
Member
That stuff is 40mm thick and it was only 8 months since she was AF fresh and relaunched in mid February. Yes definitely a softer eroding AF paint this time. It was dangerous because I could not get of trouble if caught in a strong current on a Spring so I cut my season short and haul her out a month early/
Sailing steve
Active member
Judging by the state of my hull when lifted that's exactly what I applied this spring...
ritchyp
Member
You took the words.......
Fantasie 19
Well-known member
I reckon they all are...
thinwater
Well-known member
A few things to consider:
- By the time you remove the anti-foulant the copper/zinc content is only about 20% of new. Concluded from testing many samples of sandings and scrapings.
- Any sanding/scraping dust is bad for your lungs, and in excess, can cause serious lung disease. Think of miners. So mask-up and use a vacuum sander either way.
- Any sanding dust is bad for your neighbors. Always wet or vacuum sand, including fiberglass and topside paint. Metal grinding dust is even worse (leaves rust spots).
- Non-copper antifoulants can be very good (I have one on my boat--Total boat Krypton, proven to 3 years), but the several agencies have held back on banning copper because they are not sure that other pestacides are not worse. Irgarol comes to mind. Same question re. human health. Maybe better ... and maybe not.
thinwater
Well-known member
A 35-foot boat is about 200 square feet and will take less than 1-gallon per coat. With a roller that should take 30 minutes or less. Labor is not a factor, after surface prep, only the cost of paint and whether more actually helps. If it takes longer than that you are either using a brush or a mini-roller, and there is no sense in that. It's like room painting, very fast once it's taped and the tarp is down. Just get into a rhythm, like painting a house.
Tip: Use a 3- to 4-foot extension on the roller. This gives better control, you don't have to bend over, it's easier on the wrists, and it is faster and easier to control (two hand grip). I've painted a lot of bottoms.
Tip: Use a 3- to 4-foot extension on the roller. This gives better control, you don't have to bend over, it's easier on the wrists, and it is faster and easier to control (two hand grip). I've painted a lot of bottoms.
Refueler
Well-known member
If you use an extension handle for roller ... try this trick to reduce amount of paint running down handle onto your arms / hands :
Take a plastic drinks bottle cut bottle so you have the neck and about 1" of bottle ... slide and tape handle through the neck with bottle catching drips / runs etc.
Take a plastic drinks bottle cut bottle so you have the neck and about 1" of bottle ... slide and tape handle through the neck with bottle catching drips / runs etc.
thinwater
Well-known member
Has that actually happened? With the correct amount of paint on the roller, I don't think I have ever experienced that, through many boats and a good many houses. Brushes, heck yes. But the paint should only be on the nap, not any part of the frame and barely on the hubs.
I also favor wearing assembly gloves (something like below) for roller work rather than examination gloves. About $3, last through a bottom job, much better control, less fatigue, and as a result, better quality work. Wear exam gloves under them for more protection, if you like, but you should not be getting that much on your hands with good technique.
Refueler
Well-known member
The 'tip' is for any roller with handle jobs .. not only this ...
But yes - I have seen and had antifoul paint run down a roller handle ...
But yes - I have seen and had antifoul paint run down a roller handle ...
rogerthebodger
Well-known member
So have I and its not nice to clean off.
I have to antifoul my boat early next year and will try to remember the trick
thinwater
Well-known member
I think you will find that if you use a short extension this will not happen. You will not need to apply excess paint to the roller because you will be applying slightly more pressure, and you will work faster because you have more freedom of movement. My handles and extensions stay pretty clean, maybe a few light hand prints, and I sure don't remember cleaning them with solvent, not even the hubs. It just works better. You really need to try a 3- to 4-foot extension. This is simply the right way to use a roller on a boat. Then touch up with a chip brush around the supports etc.
Neeves
Well-known member
Our experience would be:
If you buy a paint with a high copper content (the amount of copper is defined on the tin) stir it well, keep it stirred then the paint is sufficiently thick that it will not 'drip' off a roller provided you load the roller sensibly from a paint tray. If you try to thin the paint down, to give greater coverage it will drip and the life of the application will be reduced (because you have applied less than the optimum amount of active ingredient).
To answer the OPs question - you will need to apply 2 generous coatings of a good AF + extra on the leading edges and waterline.
In general for AF - its a competitive market - you get what you pay for, more expensive paint has a higher copper content, better biocides and better resin systems and thus lasts longer. The thickness of the coating determines effective life and 2 coats will last longer than one coat.
The best AF are for commercial and professional application, only - Hempel's Globic and Jotun's Quantum Ultra - and are difficult but not impossible to buy.
It costs you to AF - you need to buy the paint, rollers etc, you need to travel to the yard, you need to pay to be lifted in and out + your labour and that of your partner. - Unless you love painting with poisonous paint systems its worth doing it well and not stretching the paint to parsimonious coating thicknesses. We would achieve 2 years life with either Globic or Quantum Ultra, 2 generous coats. warm waters, we would use the boat regularly and we could make good average speeds.
Most AF 'work' because the flow of the water over the hull does not allow the fouling to 'cut' through the coating and develop a strong bond to the hull. Basically you wash the fouling off. Leave you yacht for a couple of weeks or a month in the summer and the hull will develop a coating of slime which will mask the AF (or Copper Coat) and allow the fouling to start.
You can buy AF for stationary marine vessels, ships laid up - but I have no idea what they are called. There are silicone coatings for leisure craft but they are notable for their lack of success in penetrating the market (and some commercial operators, Maersk, Princess, who have tried them have reverted in whole of in part to conventional AF)
Jonathan
rogerthebodger
Well-known member
I use Hempel's A/F that is left over from the commercial boat when they do A/F so cheaper.
I use 20 lits for my 15-meter boat that gives me 2 coats and some for the water line chines and keel edges.
It generally lasts me 2 years but could go longer as the as the Hempel's has a 3-year life span on the fouling is quite light when pulled out after 2 years.
I generally pressure wash and the get 2 guys from the year to paint the anyifouling which helps the local workers
I use 20 lits for my 15-meter boat that gives me 2 coats and some for the water line chines and keel edges.
It generally lasts me 2 years but could go longer as the as the Hempel's has a 3-year life span on the fouling is quite light when pulled out after 2 years.
I generally pressure wash and the get 2 guys from the year to paint the anyifouling which helps the local workers
B27
Well-known member
Personally, I'm finding that no amount of paint seems to offer great performance for a whole season.
So if you accept a need to dry out and scrub in Summer, maybe there's a case for putting on one coat in winter and anoher in summer.
Then you have fresh AF during the peak growth warm water season.
Personally, I put on one coat of hard AF and scrub often, which is the bonus of a drying mooring.
So if you accept a need to dry out and scrub in Summer, maybe there's a case for putting on one coat in winter and anoher in summer.
Then you have fresh AF during the peak growth warm water season.
Personally, I put on one coat of hard AF and scrub often, which is the bonus of a drying mooring.
