Area/volume/antifouling paint F-27

[Rum_Pirate]

Have a Corsair F-27 trimaran and need to antifouling it.

Corsair F27 (Corsair Marine) - Sailboat specifications - Boat-Specs.com


Does anyone have the area of antifouling on a Corsair F-27 trimaran, or the volume of paint required ?

My googling efforts have been fruitless.

 

[[70521]]

Should be a simple job with a tape measure to work out the surface area that needs painting.

 

[AngusMcDoon]

My 30' Dragonfly 920 was fine with a 3 litre tin.

 

[Chiara’s slave]

My 30' Dragonfly 920 was fine with a 3 litre tin.

We used pretty much that last time. The very last time in fact, we have coppercoat now.

 

[Rum_Pirate]

Should be a simple job with a tape measure to work out the surface area that needs painting.

Could do.

Main hull 27' x 8'2" x 0.85= 187.50 sf
Outriggers 25' x 2' x 0.85 x 2 hulls = 85.00sf
Total =272.50 square feet.

Was thinking of using this Cukote Antifouling Paint | West Marine
Coverage: 173sq.ft. @ 5.0 mil. DFT, 346sq.ft. @ 2.5 mil.
Active Ingredients: 47.5% Cuprous oxide

so 2 (US) gallons of paint.
HOWEVER I was trying to find somebody that does have a Corsair F-27 trimaran and that they would be able to tell me how much they actually used on their F-27 rather than the 'theory' calculation.







This is what my googling ended up with:

How Much Antifouling Paint | International
Determining how much antifouling you will need is fairly simple. Here are two quick guides to help you purchase the correct amount:
1. Calculate the area needing paint. For a rough estimate of the area to be painted, multiply the length of your hull (LOA) by the beam and multiply by 0.85 (LOA x B x 0.85 = Area). Then divide the area by the coverage of the paint you’ve chosen to determine how many quarts per coat you will need, or
2. Refer to the reference chart below for a quick estimate of how much antifouling paint is required for two coats:

 

[AngusMcDoon]

HOWEVER I was trying to find somebody that does have a Corsair F-27 trimaran and that they would be able to tell me how much they actually used on their F-27 rather than the 'theory' calculation.

A Dragonfly 920 is pretty similar to a Corsair 27, just a little bit bigger. So if 3 litres does a 920 then 2.5 litres will do a Corsair 27. I think that's a much better guide than trying to work out the surface area of a complex shape.

 

[Chiara’s slave]

Rum pirate, your F27 may have a beam of 8ft2 at deck level, but it's about 2ft at the waterline.

 

[Rum_Pirate]

Rum pirate, your F27 may have a beam of 8ft2 at deck level, but it's about 2ft at the waterline.

A lot more than that - goes a bit up the sides. Perhaps that is why the theory is to use a 0.85 multiplier.

Sandy's post above : "Should be a simple job with a tape measure to work out the surface area that needs painting."

I suspect that I could measure with relative accurately several 'strips' from waterline to waterline on each of the hulls.

But typing a request on a forum (after googling) is so much easier. ?

 

[Chiara’s slave]

A lot more than that - goes a bit up the sides. Perhaps that is why the theory is to use a 0.85 multiplier.

Sandy's post above : "Should be a simple job with a tape measure to work out the surface area that needs painting."

I suspect that I could measure with relative accurately several 'strips' from waterline to waterline on each of the hulls.

I’m the ex owner, you might recall. Really, it’s a narrow waterline. Thats what is throwing off your calculations. I remember using one can 2.5 litres, no more.

additionally, your underwater profile is nothing like those in the estimator.

 

[Rum_Pirate]

I’m the ex owner, you might recall. Really, it’s a narrow waterline. Thats what is throwing off your calculations. I remember using one can 2.5 litres, no more.

additionally, your underwater profile is nothing like those in the estimator.

Thanks, that does help me.
That was for one coat applied by a roller?
2.5 litres is 0.66043 US gallons (yes SXM uses imperial).

I may very well follow Sandy's suggestion and measure several say 4'0" wide 'strips' from waterline to waterline on each of the hulls.

Will probably buy one gallon as the cost per gallon bought in 'quart' cans can be uneconomical.

Then will have some for an extra coat at waterline, a second coat on rudder and on the daggerboard, particlilatly the leading and trailing edges.

 

[Chiara’s slave]

I wouldnt bother with the rudder and daggerboard, you pull them up when you leave the boat, don’t you. And make sure it’s hard racing antifoul, then you can scrub it, on the beach. And put it on the trailer without grinding it off.

 

[Rum_Pirate]

I wouldnt bother with the rudder and daggerboard, you pull them up when you leave the boat, don’t you. And make sure it’s hard racing antifoul, then you can scrub it, on the beach. And put it on the trailer without grinding it off.

I will have to put at least one coat on the rudder.

i) it is nearly down to the gelcoat.​

ii) it is green (what's left of it) in splotches and areas and the new antifouling will be black, so appearances come into it.​

​

Appreciate the advice about using hard racing antifouling.

 

[Chiara’s slave]

I will have to put at least one coat on the rudder.

i) it is nearly down to the gelcoat.​

ii) it is green (what's left of it) in splotches and areas and the new antifouling will be black, so appearances come into it.​

​

Appreciate the advice about using hard racing antifouling.

Black…. You could just paint it (the rudder) with car or marine paint. I’d always use white so I can see the fouling personally, though black will look smart. But then perhaps you have antifoul that actually works in your part if the world. Ours, you might as well paint the boat with fertilizer.

 

[Rum_Pirate]

Problems for my Mako 23 was the 'limestone/coral' deposits above the waterline.
Easily removed with vinegar and buffed up.

Had good results underwater with Antifouling, Islands 44 Plus Black Hard

USD325.00 EACH/US Gallon

Used to be able to get a TBT additive sold in a small container to 'up' the effectiveness (I never used it) of antifouling, but don't see it anymore.

 

[Spirit (of Glenans)]

Have a Corsair F-27 trimaran and need to antifouling it.

Corsair F27 (Corsair Marine) - Sailboat specifications - Boat-Specs.com


Does anyone have the area of antifouling on a Corsair F-27 trimaran, or the volume of paint required ?

My googling efforts have been fruitless.

International Paint's brochure contains formulae, utilising various dimensions of a boat, to indicate how much paint is required. There are formulae for fin keel yachts, displacement motor vessels inter alia.

 

[Rum_Pirate]

International Paint's brochure contains formulae, utilising various dimensions of a boat, to indicate how much paint is required. There are formulae for fin keel yachts, displacement motor vessels inter alia.

I found something like that in Post#5.

But unfortunately they didn't have a formula for trimarans. I think that Sandy's suggestion in Post # 2 is what I shall have to resort to doing.

 

[Chiara’s slave]

And your black stuff, I don’t think we are allowed that. It has actual weed poison.?

 

[Spirit (of Glenans)]

I found something like that in Post#5.

But unfortunately they didn't have a formula for trimarans. I think that Sandy's suggestion in Post # 2 is what I shall have to resort to doing.

Oops! Didn't spot that and too small to see when speed reading on my phone?
Assuming you have two hulls of similar size and shape and one either bigger or smaller(I'm not familiar with the characteristics of your boat) applying the formula for a motorboat (no keel), to the hulls individually might give you a figure to work with, rather than trying to work out the area of multiple compound curved shapes.

 

[Chiara’s slave]

Oops! Didn't spot that and too small to see when speed reading on my phone?
Assuming you have two hulls of similar size and shape and one either bigger or smaller(I'm not familiar with the characteristics of your boat) applying the formula for a motorboat (no keel), to the hulls individually might give you a figure to work with, rather than trying to work out the area of multiple compound curved shapes.

Even then, the wetted surface is low, designed that way. At the fattest part of an F27 the main hull probably measures about 4ft from waterline to waterline via the bottom. Tapering to a foot. The main hull Ikd estimate to average 2.5ft, x 27, which gives us under 70 sq ft, 7sq m. And less than half each for the amas. You can splash it on all over with 2.5 litres.

It’s only displacing 1.3 cubic metres of water. And the underwater sections aren’t that far off hemispherical, though it is flattened under the mid section and aft, to facilitate planing.