View previous topic :: View next topic |
Author |
Message |
J64TWB
Joined: 24 Dec 2013 Posts: 1685
|
Posted: Sun May 12, 2019 4:03 pm Post subject: any physicists out there? |
|
|
The more I looked into this, the more confused I am about heat and colors.
First of all, please tell me if I am overly concerned. My goal is to keep a new SUP on a dock all Summer so not to carry it a long way for each use. It is red on one side, white on the other. It’s a Bic Ace-Tec construction, no vent.
If I leave it in the sun all Summer with the white side up am I at risk of delamination or are most modern boards immune? I’ve heard of inside of hot cars, on hot sand, but this is just mounted over water on a dock, just direct Sun and air temperature.
I am not concerned about cosmetic fading or looks, just outright damage.
If I were to try and make a cover for the Sunny side, what material? I started looking into and this is where I got confused.
Some say silver reflective is the worst because it retains heat (like metal). Especially if it has insulation under (like most board bags). I would think it reflects all the energy?
One board bag company says light grey absorbs least heat
One company says white.
Spacesuits have always been white. Not reflective, light grey or silver but white. The tiles on underside of space shuttle are black as they try and absorb the heat of re entry?
I’m starting to think just leave the white side up all Summer and forget about it?
Any physicists out there? |
|
Back to top |
|
|
westender
Joined: 02 Aug 2007 Posts: 1288 Location: Portland / Gorge
|
|
Back to top |
|
|
U2U2U2
Joined: 06 Jul 2001 Posts: 5467 Location: Shipsterns Bluff, Tasmania. Colorado
|
|
Back to top |
|
|
carl
Joined: 25 Feb 1997 Posts: 2674 Location: SF bay area
|
Posted: Sun May 12, 2019 7:25 pm Post subject: |
|
|
I would think the ASA plastic layer on the Bic would get brittle and start to delam because of constant UV rays of the sun. Cover it with something light colored to keep it out of the sun. As for heat, I used to keep an older Bic in a hot car. It didn't delam but it did split in a small area on the seam. |
|
Back to top |
|
|
manuel
Joined: 08 Oct 2007 Posts: 1158
|
Posted: Sun May 12, 2019 9:32 pm Post subject: |
|
|
One board painted red over and white under was left on the roof of a hotel here.
I believe on its side? It was delaminated, did it happen before or after? I don't know.
Another board (mostly white) was left out in the sun too but on the beach standing up. It lost all of its color so now we can see the epoxy and carbon kevlar construction. No delam here and apparently not a problem regarding boards left out in the sun here (DR)...
I'd say avoid sun at all cost, prefer white for sure.
Cover and let air flow around it. _________________ *NEW* - Manu's Windsurfing Blog, The STORE! |
|
Back to top |
|
|
J64TWB
Joined: 24 Dec 2013 Posts: 1685
|
Posted: Mon May 13, 2019 6:29 am Post subject: |
|
|
Do we think an air space is critical? I have some old 2 sided foil bubble wrap they sell at Menards. Was thinking of using that to cover it but then I read that is the worst.
Maybe just a breathable canvas cover? Under the dock won't work because of wave action.
On shore and tress are not an option. |
|
Back to top |
|
|
westender
Joined: 02 Aug 2007 Posts: 1288 Location: Portland / Gorge
|
Posted: Mon May 13, 2019 6:36 am Post subject: |
|
|
I would be more concerned about the ventilation gap than the solar shield color. |
|
Back to top |
|
|
Brian_S
Joined: 11 Jun 2005 Posts: 249 Location: SE Michigan
|
Posted: Mon May 13, 2019 12:13 pm Post subject: |
|
|
Not a physicist, but an engineer with some experience in radiation heat transfer.
I'm with Westender on this one. A sun shield of any color that blocks the sunlight (and doesn't touch the board) will help protect the board better than putting it into a cover that touches the board. In other words, 'shade' the board with something.
The foil reflective board bags are good, but the board will still get warm inside. I did run an experiment a few years back to measure the board skin temp on a white board in and out of a foil board bag. Can't recall any of the numbers, and the bags worked well, but the board will still get warm in the board bag. And then leaving a wet board in a warm board bag can do things to the paint a grow mold.
Also, white colors can deceiving since our eyes see only a small part of the spectrum. White snow, for example, reflects sunlight in the visible spectrum and absorbs sunlight in the IR spectrum. _________________ Brian S
www.miwindsurfing.com |
|
Back to top |
|
|
U2U2U2
Joined: 06 Jul 2001 Posts: 5467 Location: Shipsterns Bluff, Tasmania. Colorado
|
|
Back to top |
|
|
nw30
Joined: 21 Dec 2008 Posts: 6485 Location: The eye of the universe, Cen. Cal. coast
|
Posted: Mon May 13, 2019 1:02 pm Post subject: |
|
|
The UV penetration would be a bigger problem than the sun's heat on a white surface, over a period of time.
Also you have to consider the color of the dock, if it's dark, it will get hot, so I wouldn't want to put the board on the dock unless it is shaded. |
|
Back to top |
|
|
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You can attach files in this forum You can download files in this forum
|
|
|