How much does antifoul paint weigh?

[Deleted User YDKXO]

Every year my bloke in Majorca says to me that I should think about having all the old layers of antifoul scraped off my boat because a new layer or two every year adds weight and loses speed. I'm not convinced by this especially as it sounds like something expensive
So can anyone hazard a guess how much 2 layers of antifoul paint every year weigh assuming it's the non-eroding variety? What's involved in scraping off the old antifoul anyway? Is it costly?

 

[seamaster30]

You could try reading the weight on the tin /forums/images/graemlins/smile.gif

 

[Deleted User YDKXO]

[ QUOTE ]
You could try reading the weight on the tin

[/ QUOTE ]

Yup that thought did occur to me but how much of the paint evaporates in the drying process?

 

[Questor]

As above x the number of tins per application x number of years since last scraped, I'd have thought.

Re removal, manually doing it yourself is, I think, the most horrible boaty job I've embarked on.

I swore I'd never do it again, so last yeat I got Symblast in to do it. And what a fine job they did.

Cost was around £400 ish. Not sure if he'd go to Majorca though.

 

[jfm]

weight on tin minus say 30% solvent evaporation?

My old boat was lifted yesterday and surveyed. For the 5 seasons of its life it's had eroding a/f for last 2 seasons and hard a/f for 3 seasons before that, so overall it's had 10 coats in its life. I was amazed how thin it was when surveyor scraped it off yesterday to do his osmosis checks. I certianly wouldn't pay to have it scraped off. And a couple of layers of paint must help agianst osmosis

I'd definitely recommend the eroding stuff: last year my hull was clean on lift out and yesterday it was pretty much the same. I've started off the new boat with M66 and plan to continue, so will not get any build up I expect

I'll post pics of Micron 66 results soon, when I get a mo.

 

[gjgm]

cost
as it happens. was talking to someone over the w/e. Think it was about £800 for 45ft.
As a guide...

 

[adrianb]

Blimey £233 for a tin..................... it should last 2 seasons !!!

 

[mjf]

I'm with jfm on this issue.

I would be inclined to leave whats left of the old stuff where it is.


Frankly the 'extra' wt as % of the displacment is nought so I would not do it for this reason alone.

 

[jfm]

[ QUOTE ]

Blimey £233 for a tin..................... it should last 2 seasons !!!

[/ QUOTE ]

They say it will do 2 seasons, and they're prob right. I'll post photos soon. It's much <£233/tin when bought in big drums for trade use!

 

[Deleted User YDKXO]

I think you're right. According to last year's bill, my bloke used 10 litres of paint per single layer and I had single layers applied last year and the year before. Even if the previous 6 years had double layers, thats still only 140 litres of paint, say 140kg. Assume that 30% has evaporated so that leaves only 100kg on the boat and even that's too much because some will have fallen off. Less than 100kg of paint isn't going to make much difference to the performance
I see I was billed £270 per 5 litres of Titan Medium Speed antifoul paint last year /forums/images/graemlins/mad.gif. I think this year I will be buying it myself

 

[[2068]]

I'd be surprised if the antifoul left on any <50ft boat weighed more than 25-50kg.
Putting your crew on a diet would make more of a difference.

If it's gone all uneven and bumpy, thin in places, thick in others, then that's a diferent story: that's going to mess up your top speed a bit.

dv.

 

[Bandit]

If the coating is in good condition ie not flaking and there is only say 10 years worth on the boat i would not bother.

I agree with eroding antifouling as only a fraction of the ammount is left at the end of the season especially after pressure washing. I use it and i am a fan of it.

 

[johndove]

I would not woory about the weight, but drag!

Layers of old flaky paint must make drag, all racing boats have antifoul sanded smooth or a highly polished.

Even a slight growth slow things down.

 

[Deleted User YDKXO]

I was wrong. A 5 litre can of Interspeed weighs 8kg not 5kg as I assumed so that leaves maybe upto 160kg of paint on my boat. Anyone think thats going to affect performance much?

 

[MapisM]

Yes. It does improve the boat stability a little bit! /forums/images/graemlins/smile.gif
Other than that, if nice and smooth, I wouldn't bother.