Vinyl Wrap Colour and Hull Heat Retention

[Blakhomer]

I can't seem to find too much information about this online. We're looking at getting the topsides vinyl wrapped to spruce up the boat a bit. If need be, I'll go with a glossy white but Im wondering if anyone has a dark colour on their hull and can speak to the heat retention. We live in the tropics and it would seem counter intuitive to put dark colours on a boat in this climate. Just double checking.

[S/V Illusion]

We live in North America’s version of the tropics and have found it makes very little difference inside the boat. While I’ve measured the difference in topside temperature between our hull and my neighbor’s vanilla boat, that doesn’t affect interior temperature as the interior glass doesn’t significantly radiate much heat. And a dark topsides is much prettier than the generic vanilla.

[mjscottinnc]

Originally Posted by S/V Illusion

And a dark topsides is much prettier than the generic vanilla.

Well that’s up for debate. Personally I find a clean white sailboat very appealing. But then again my favorite cake is white cake with white icing. Each to his own.

[AndrewA2]

i have read from various sources that anything off-white makes a HUGE difference to the temp inside the boat. Not just from a dark to light shade, but even a subtle off-white makes a noticeable difference.
I would very much like to hear if anyone else has actually been able to compare like-for-like on this?

[thinwater]

Originally Posted by AndrewA2

i have read from various sources that anything off-white makes a HUGE difference to the temp inside the boat. Not just from a dark to light shade, but even a subtle off-white makes a noticeable difference.
I would very much like to hear if anyone else has actually been able to compare like-for-like on this?

Since this is VERY much dependant on hull construction (coring), liners, windows, and ventilation, I would not hold my breath for a meaningful answer. Kinna like asking if a white car is cooler than a black car without specifying "which car." I've had white boats and I can tell you there is a wide range just between those.

You could also Google heat absorption vs. color, assume an insulation value, and go from there.

[CalmSeasQuest]

FWIW, Our Fountain Pajot Saba was wrapped last year using 3M 1080 film (Sterling Silver.) We've spent most our time in the Bahamas and USVI's and haven't noticed any difference in cabin temps.

[Stewie12]

A dark colour may fade faster with the sun.

[Jono as 2234]

I was anchored next to a black steel yacht in the Whitsundays. Even in winter one could fry an egg on the hill at midday

[a64pilot]

Originally Posted by Stewie12

A dark colour may fade faster with the sun.

Cheap vinyl will fade almost on the first day, the good stuff will from a fade perspective last as long as paint, many signs are now vinyl for instance.
The aircraft in this article was wrapped, we initially wrapped it in a red color, but GE had it redone in blue. That’s the advantage of vinyl, however it’s easily damaged and looks great 20 feet away, but not up close. Most vinyl will have thin groves on the underside or be full of tiny holes to let air out on installation, and uo close this is visible.
https://generalaviationnews.com/2010...d-thrush-510g/

Plus a computer can print graphics on vinyl just like it can print a photo, even a skilled painter couldn’t hope to match that, so if you have complex graphics, vinyl is the way to go.

[LakeSuperior]

A significant factor in human comfort levels beside air temperature is the radiated heat which is dependent on the wall temperature. For example, you will feel like you are in an oven if the wall temperatures are 85 deg F versus 75 F with the air temperature constant at 70 F.

So, what does that have to do with hull color? The most important factor here is are the topsides cored or solid glass. In the north country solid glass topsides sometimes have a layer of insulation glued to them to reduce condensation.

A colored hull is absorbing 20 or 30 percent more solar energy due to the solar absorptivity of the surface. This may be 200 watts per meter squared or more versus white topsides. This additional energy will cause the temperature of the inside surface of a solid glass hull to be much higher than a cored or insulated hull.

This higher temperature radiates more energy to the cabinets and stuff hiding the view of the inside surface of the hull. Consequently, the stuff becomes warmer thus radiating more heat to your clothing and skin. The interior air heats up due to convection with the stuff. So overall, a warmer cabin.

In summary, in the tropics you would probably sense a very noticeable difference in the cabin temperature with a colored hull primarily if your hull is solid rather than cored.

A cored hull dramatically slows the transfer of heat into the interior of the boat. So the effect of a colored hull would be muted.

[Blakhomer]

Thanks everyone for the feedback. Sounds like different results across the board and thats perhaps attributed to what LakeSuperior mentioned around the build of the topsides. S/V Illusion's Alden hull construction are cored from what I can read. From what I can read about the construction of my yacht, there does not appear to be an insulated hull.

"The robust, hand-laid solid fiberglass hull is built to CE Offshore A category standards. The hull is supported by Beneteau's proven grid system-a bonded fiberglass hull liner that stiffens the hull and spreads loads from the rig throughout the boat. The deck is a cored sandwich construction to keep weight down, although a solid laminate is used to support high-load areas. The bulkheads are bonded 360 degrees to hull and deck."