What Reflects More Heat?

[ssullivan]

Assuming a boat has a teak deck (if it should or not is a whole different thread... ha ha ha):

What would reflect the most heat/light in the tropics? Leaving it untreated, or using Cetol or something of that nature to get a good shine (but kind of dark color)?

[Alan Wheeler]

It's kinda the same but different. It's not what reflects heat, but what absorbs it. The darker something is, the more energy it absorbs. Energy is both light and heat. The heat being the infra red band. Two other colours/colors that are bad at heat absorbtion are Red and Blue. These become very efficient at absorbing the Infra red and ultra violet bands.
Interesting little story. Many years ago now, a Yacht was built in NZ called Stienlager. The paint and glue products were formulated and supplied by Epiglass at the time. The powers to be wanted the entire boat painted Red. But the team at Epiglass said No way. The heat absorbed in the infra red band when in the tropics, would take the surface temp so high, they would reduce the strength of the epoxies. They even provided the estimated deck temp (can't remember the figure now) and it was really really hot. So the deck got painted white and only the hull was painted Red.

[Pblais]

You sure wouldn't want anything with a shine aka Slippery! Cetol is not for decks. You would of course be talking about other teak deck products.

Most of the teak deck treatments would end up about the same I would think. They all darken to some extent. Untreated would be the lightest color. Not to say leaving it untreated is good or bad but it wouldn't be slick and it would be as light as teak gets. Brand mew the untreated deck would function best.

Wood has some insulation properties though in the end I don't think that would matter a lot in terms of heat during the day.

[GordMay]

Teak decks are hot - no matter how you treat them.
Many experienced cruisers allow teak decks to fade (bleach) to gray.
Rinse decks as needed with salt water to remove dirt. This reduces wear and tear from particles under foot, and the remaining salt helps to preserve the teak (see Yandina’s site).
Teak trim requires different care than teak decks. Varnished exterior teak lasts longer and provides more protection than an oil finish. Sand and varnish teak trim as needed.

and here’s some good advice ...
How to maintain and caulk teak decks on boats:
http://www.yandina.com/TeakDeck.htm
including:
Background & Theory
No Nos ~ Things you never do to a teak deck.
Do Doos ~ Things you should always do to a teak deck.
And much more ...

FWIW
Gord May

[ssullivan]

Yes, I suppose I am talking about other teak deck products. It just looked an awful lot like Cetol. I'm sure it's not, now that you point out the slip factor.

I am actually looking at a possible boat to purchase (with a big loan) this weekend. It is one of the only boats in my meager price range that is capable of offshore work (I think). It's got these teak decks that are treated with some material that looks like Cetol in the photos.

Since we are planning to sail both in cold and warm climates at some point, I was concerned with the head absorbtion (thanks Wheels!) characteristics of this boat. That said, it is the only properly setup crusing boat we have found so far in our price range.

Thanks for the input. We may have to live with the extra heat... We will be sure to let the decks peel and go natural to bring a lighter gray color if we go with this one.

Thanks for the input.

Pblais once whispered in the wind:
You sure wouldn't want anything with a shine aka Slippery! Cetol is not for decks. You would of course be talking about other teak deck products.

Most of the teak deck treatments would end up about the same I would think. They all darken to some extent. Untreated would be the lightest color. Not to say leaving it untreated is good or bad but it wouldn't be slick and it would be as light as teak gets. Brand mew the untreated deck would function best.

Wood has some insulation properties though in the end I don't think that would matter a lot in terms of heat during the day.

[Alan Wheeler]

Hi Sean, ther are quite a few different "oil" type products out there. I mean by this, a product that soaks into the timber, not a top coating type product like Urathane or Varnish. There are top coating products that have anti-slip properties however. A soak in type product will not "peel". It will however, slowly migrate down deeper,PLUS, and wear away on the suface as UV breaks it down and water carries it away.
Timber is a good insulator from heat. So transfer down into the boat will be minimal.( Although I haven't been in the tropics, so take my experieance with a grain of salt.) But the surface temperature is the problem. You have to walk on it. I doubt that the darker "oiled" color is going to make it tooo hot to be unbearable, but it will be warmer.
Have you ever noticed in Nature, how a surface becomes darker when wet, thus absorbing more heat and aiding it to dry out faster, thus becoming lighter in color and thus absobing less heat. Neat huh. We have an awesome creator.

[Jeff H]

I do not know the age of the boat you are considering, but having owned a boat with teak decks in Florida, I would consider teak decks a deal breaker if I were planning to keep the boat in the tropics, live aboard, or do distance cruising. I know that this runs counter to many of the popular thoughts on teak, but over the many years that the boat was in our family, a variety of treatments were used and each seemed to require very frequent retreatmant (something like every 4 to 6 weeks). Allowing the decks to go grey eventually lead to the need to replace bungs and allowed water into the fastenings rotting out the subdeck and deck beams. The teak decks were unbearably hot to walk or sit on and continued to radiate heat above and below deck long into the evening.

My experience with teak over glass decks is that they have a limited lifespan before a major rebuild is required. Depending on where and how the boat is used and its original construction, that lifespan can be as little as 10 years and as long as 20 years. Teak decks can mask problems occuring in the deck core below so that a deck failure can occur without warning, unlike with a glass deck where delamination becomes readily noticable.

Respectfully,
Jeff

[ssullivan]

Good Pont, Jeff.

So many factors..... economic, liveability, ability to do offshore work, and now teak decks!

It's almost as if you just have to make a plunge when you see a boat you like, and then rationalize it later on with some facts that are convenient.

Thanks for the input.