Black painted fibreglass?

[Tim B]

Visibility is another consideration. Black is very hard to see in poor light against a dark sea. This might not be a problem in normal operations, but it will dramatically change your odds in a rescue situation.

As has been mentioned, heat is bad for the structural properties of composites in particular. You'll need substantially bigger structure if you intend to operate at higher temperatures. This means more weight.

A little dark trim to highlight the features is fine, but don't go all-black.

Tim B.

[sean-nós]

Originally Posted by JordieS

What did you use to sand it?

My hands and wet paper, I like to feel it as I sand hence I have no fingerprints

No gelcoat or clearcoat just paint. "toplac international"

[JordieS]

Sean-nos I sent you a pm regarding my questions about your boat so we can get back to the question on this topic.

[JordieS]

How hot would a light grey/silver get?

[Mr Efficiency]

Originally Posted by Poida

Hi Tunnels

When I was in the paint industry, I thought it would be a good idea to manufacture a light coloured roof paint, even a white one.

We use to do coatings for a roof tile manufacturer who basically only produced dark colours. I asked one of their marketing people why they didn't sell white tiles to reflect the Sun's heat.

He told me that they made some light coloured tiles as a market research when people chose what coloured tiles they wanted for their house. Noone wanted them, they all chose dark colours. In our heat.

Tunnels, Australians are not mad, we're F^#*ING stupid.

White roofs get as dirty as all heck in record time. Been there, not going back.

[troy2000]

Originally Posted by sean-nós

There are only two colors to paint a boat, black or white, and only a fool would paint a boat black.
-Nathanael G. Herreshoff

You beat me to it. That quote was the first thing that crossed my mind when I started reading the thread...

[rxcomposite]

Here is something published by Martin Hollmann in "Modern Aircraft Design" Vol2.

"For the same type of surface but painted white, a surface temperature of 125 degree Farenheit was measured for a 95 degree F day."

Just don't paint your boat with a color that will reach the Heat Distortion Temperature of whatever resin you are using.

[ondarvr]

Depending on the resins used and the care taken during the build, dark colors don't pose much of a problem. It can frequently create cosmetic problems with the wrong resin or poor workmanship though.

The biggest problem is post curing of the part resulting in print from the fabric showing in the gel coat due to shrink and movement of the resin. This is most common in boats being built in the winter when the shop conditions aren't good, the temperatures are low during construction leaving a great deal of residual cure. These boats may never see temperatures higher than the mid 60s F until several months down the road when they are out in sun and can reach temperatures in the 180F range. The cosmetics are negatively affected but the physical properties may increase. Resin type and how well it was used has a great deal to do with the amount change in surface profile too.

[tunnels]

Some where ,sometime ,Proffessional boat builder magazine had a story on the very subject of colours and amount of heat you could exspect on a loverly !!
Was very interesting and the amount of heat was increadable .
Cant speak for wood or other materials But glass i would never want to own a dark coloured boat (any dark colour )
During the manufacture of glass boats there is always air entraped in the resin and glass.
Its very nature resin produces gas from the chemical reaction between the catalyst and the promoting chemicals in the resin to make it all go hard so there are pockets within the lay up .
Excessive Heat will cause these pockets to exspand and one day you will look at your nice pretty shiney black boat and wonder "what the hell" !! Where did those marks come from ??
what caused them??
Stupidity is the biggest cause of just about any problem !
then workmanship , that accounts for 90 % plus of glassing problems
lastly the product !! and thats usually directly related to the first two on the list .
Have a nice day !


Black is always associated with dead things or things that are dead so where do you fit in scheme of things ??

[JordieS]

You have to remember that black is an extremely cool colour, you will cruise past people and they will be thinking "Better stay back from him" hahahahahaha, James Bond had a black boat in "The World is not Enough". Best boat chase scene in that movie.

[tunnels]

Sorry black in my book is not cool !! its dumb non thinking type colour !
But i will say dark charcoal metalic with a touch of black pearl added is a nice colour But its just used for a back ground color to hi-light reds and yellows, blues , purples and greens and oranges . But not dead black !!

[MikeJohns]

Originally Posted by Tim B

Visibility is another consideration. Black is very hard to see in poor light against a dark sea. This might not be a problem in normal operations, but it will dramatically change your odds in a rescue situation....

I was interested to hear a SAR talk recently where they said Black is surprisingly easy to see, but that white hulls make the SAR crews groan since they are so camouflaged in a rough sea. But the deck color is most important in an aerial search, or maybe the antifouling paint if it's lolling .

But that aside the expansion coefficient for GRP is high and it's sensible to keep it as cool as possible it's a cause of outer skins disbonding from cooler cores and inner laminates and the heat softens the glue.

[Tim B]

Depends on the conditions and time I guess, but I'm slightly surprised by that. You'd think that a black deck against a dark sea at night would be pretty hard to spot. White you'd think was easier, but against spray, might be a bit harder.

Personally, I reckon that fluorescent orange on rudders and keels (at least for part of the span) is a good idea, but you rarely see it on non-ocean-racing yachts.

Tim B.