Antifoul for trailer sailer?

[WoodsToucan]

Good afternoon all!

I am getting ready to tackle the hull on my 1989 Palamos built GRP Woods Strider 24’ catamaran. I have cleaned off the very bad fouling it had, after what I suspect was a few years in a Lowestoft mud-berth, and much of the old Anti-foul came off. In many areas it is down to the gel coat. There are also about half a dozen bubbles which I suspect may be osmosis.

I intend to carefully scrape away all the remaining Anti-foul as far as far the original gel coat. Then treat the blisters - assuming they are osmosis. Then apply some kind of epoxy primer. Then what?

I have a suitable trailer and the boat will only spend 3 of the next 36 months in the water and most of that time it will be moving.

So - is my treatment scheme the right thing? Any advice gratefully received. My last boat was a large wooden one with rather different needs.

many thanks
Dan

 

[Chiara’s slave]

Congratulations on buying a very fine little boat. As to the question, it depends how long at one time, rather than the total. 3 months at one go and you’ll have a bigger beard than Merlin, but if it’s a week at a time, maybe 2 if you can give her a wipe down on a beach at half time, then I would personally do without antifoul, just build up some epoxy and give it a 600 grit smooth finish. Do it to your foils too, you need her blemish free and slippery.

 

[WoodsToucan]

Thanks for the advice. I fear she may end up in the water for 1-3months depending on how successful my trailer design is.
I am then not going to use her for at least 2 years and she will be stored in my barn.
so it sounds like some kind of Antifoul will be wise. But what?!

 

[William_H]

Regarding scraping off the old a/f you may well end up running out of patience and energy in doing a good job. Don't be ashamed, scraping a/f is like that you just do what you can. It is horrible. Promise yourself to do better next time. Yes grind out the bubbles and fill with epoxy. Then antifoul over it. As to whether you should paint a/f on it that is something I can not advise as it will depend on how long it stays ion the water and how hard it is to scrub it. I paint my trailer sailer every year before return to swing mooring. After 6 weeks it has slime etc and I begin a campaign of scrubbing in water (diving) for another 4 months. But then fiece fouling in our warm waters. So all different. ol'will

 

[WoodsToucan]

Thanks William. The scraping is not a job I am looking forward to especially but hopefully the light displacement means the area under water isn’t too huge. I wonder if you or any others on here have advice about the epoxy primer step - I am thinking to apply it to the whole of the underwater area. I am especially interested in the choice of product. I have only used it on a dingy before and I am aware there is a lot to get wrong!

 

[Chiara’s slave]

Thanks William. The scraping is not a job I am looking forward to especially but hopefully the light displacement means the area under water isn’t too huge. I wonder if you or any others on here have advice about the epoxy primer step - I am thinking to apply it to the whole of the underwater area. I am especially interested in the choice of product. I have only used it on a dingy before and I am aware there is a lot to get wrong!

With modern 2 pack it’s easy. Make sure everything is dry, and roller it on with a round edged roller to help with an even coat. Underwater primers are meant to be rough and tacky to give the af a key, so they’re the ones to use if thats what you need to do. Look at a proper hard racing type, Hempel do one that I use on my RIB, it stands a winter on the trailer, and doesnt come off on the rollers.

 

[northwind]

I would pause before painting the bottom with epoxy, by all means clean out the blisters and fill them, but if hull isn't dry, you could end up with bubbling behind the epoxy coat. The way you are using the boat its unlikely to benefit from an epoxy barrier, as it spends the majority of its time out the water.

I also wouldn't bother anti fouling, just scrub off when you can. Anti fouling paint isn't really designed for trailer sailing, they all quote a maximum time for it to be out of the water before it looses it zing. Eroding anti fouling paint will make a mess and will get all over your trailer and you when you launch and recover!

 

[WoodsToucan]

I would pause before painting the bottom with epoxy, by all means clean out the blisters and fill them, but if hull isn't dry, you could end up with bubbling behind the epoxy coat. The way you are using the boat its unlikely to benefit from an epoxy barrier, as it spends the majority of its time out the water.

I also wouldn't bother anti fouling, just scrub off when you can. Anti fouling paint isn't really designed for trailer sailing, they all quote a maximum time for it to be out of the water before it looses it zing. Eroding anti fouling paint will make a mess and will get all over your trailer and you when you launch and recover!

Thanks very much. I would certainly like to avoid the expense of epoxy primer and a/f if I can. I could try it without for this season and see what happens. Although I would like to tidy up the bottom somehow as it will be so scruffy - either left with patches of old a/f or scraped off. Feels like I should paint something on. At least the Striders are easy to beach for a quick scrub off.

 

[northwind]

Thanks very much. I would certainly like to avoid the expense of epoxy primer and a/f if I can. I could try it without for this season and see what happens. Although I would like to tidy up the bottom somehow as it will be so scruffy - either left with patches of old a/f or scraped off. Feels like I should paint something on. At least the Striders are easy to beach for a quick scrub off.

Hard to look at the bottom of the boat when its afloat... I wouldn't bother with its appearance.. go sailing and enjoy the weather..