guys, did you ever though a woman in high heels will feel comfortable? of course, its not about being utmost practical, it's about to look good! :-) wether I can stand the heat, is not that much a question, as I intend to make the antislip deck grey anyway... and as I said, I sailed a black boat already... so that is not my concern.
My worries are potential delamination (due to the shear forces in the foam/skin...) and the lack of stiffness when the foam gets warm...
does anyone know how much warmer a black boat gets compared to a medium grey one?
I agree with Rob. A friend of mine sailed the first grey Flyer from Egner. The grey was very light (3% black in the gelcoat mix) still the boat got hot while my white one stayed just hand warm...
So is it like this, that the difference between white and any other colour is significant but wheter you take a medium dark or a real dark color doesn't matter so much anymore?
Dirk
A-Cat GER 5
F-16 CHN 1 (sold)
SC 6.5 CHN 808
-- Have You Seen This? --
Re: black?
[Re: Dirk]
#92685 04/22/0709:18 AM04/22/0709:18 AM
Rolf, seems you really face different problems up there... Probably a white boat isn't a good idea there too because it's difficult to spot in the snow?? ;-)
Dirk
A-Cat GER 5
F-16 CHN 1 (sold)
SC 6.5 CHN 808
Re: black?
[Re: Dirk]
#92686 04/22/0709:26 AM04/22/0709:26 AM
That is no joking matter. Our hull covers are dark blue so the guys driving the shovel during winter can easily see it against the snow. Somebody left a white Opti under the snow once, not much boat left once they had cleaned up the last snowfall. But now I am off to the club (happy happy joy joy, sailing season is finally here again).
We went sailing today (jipii!!), and the snow got short shrift by the rain we had yesterday.
I dont think I would worry so much about the foam, but what about the epoxy (or polyester)? If you heat epoxy, it becomes soft. How are transparant finished carbon masts holding up? If that is no problem, I would not worry about deliminating. But practical handling, like Wouter described, could be uncomfortable.
On the diabgroup.com site Divinycell H grade (lowest performance) states the following… “The foam can be used in sandwich structures, for outdoor exposure, with external skin temperatures up to +185 degrees F.”
You might want to be concerned about the resin as well...the heat distortion temp might not be that high for the resin.
Regards, Bob
Re: black?
[Re: Dirk]
#92690 04/23/0708:23 AM04/23/0708:23 AM
Rolf, I built a black boat and sailed it for 13 years. The deck does get hot but all you have to do before you start is put your hand in the water and bring it up with some water in it and splash it over the deck. It's no big deal. Once you're underway more often than not water is splashing up on the deck anyway. The only real issue to consider is the breakdown temp of the resin used. And believe it of not "resins ain't resins". They can vary a lot. You can't compare a high temp re-preg resin like that used to make carbon masts to a normal resin used in boat constructoion.
I kept my black boat under cover until I needed the covered area to build a big boat. Then I moved out into the direct sun. Several years later the decks started to delaminated. It was the glue holding the layers of veneer in the play that gave out. If the boat is only in the sun for rigging and sailing then black is probably going to be OK. If you plan on leaving the boat in the sun all day every day then it would be safe to choose another colour.
If you choose to have a black boat they only have two kinds of finishes. perfect and crap. I kept this in the forefront of my mind when finishing my black boat and in the end you could use it as a mirror and many did. As black shows every minor imperfection it has to be perfect. Regards, Phill
I know that the voices in my head aint real, but they have some pretty good ideas. There is no such thing as a quick fix and I've never had free lunch!
Re: snowblack?
[Re: phill]
#92692 04/23/0708:59 AM04/23/0708:59 AM
Right, I really knew that. There are large differences between resins, and masts are probably made with pre-pregs and "cooked" in autoclaves while homebuilder resins become soft much earlier.
phil and others, thanks for sharing your experiences. delamination is the last I am looking for, I just repaired several of those spots on the old hulls... :-) I will cover the boat with a cover anyway. Here is a qoute from the manufacturer regarding temp: "Most foams have a HTD of approximately 120 dergrees F. Testing is usually done to a max of 160 degrees F but at that point you will see distortion of your sample. Resins usually have an HTD of about 140 degrees F."
Phil, what are the outside temperatures you encounter and did you ever measure the hull temperature of your black beauty when exposed to the sun on a hot day?
With a gloss black finish, you will likely be able to see even the fairing line of your extension. Like Phil said, black finishes show up everything little bump, even stuff you didn't realise existed.
black! or grey? black! no, grey! or white? black! maybe grey? black is beautiful, but... grey is just grey as the sky... white looks dirty to early, black gets to hot...
[it was a tough decision ;-)]
boat assembling starts tommorrow.
Dirk
A-Cat GER 5
F-16 CHN 1 (sold)
SC 6.5 CHN 808
Re: and the answer is...
[Re: Dirk]
#92697 05/12/0711:20 AM05/12/0711:20 AM
I am also pretty amazed... I can't find the joints between the old and the new... nicely done... looks much better than the Chinese AC bulb... haha ;-)
Dirk
A-Cat GER 5
F-16 CHN 1 (sold)
SC 6.5 CHN 808
Re: cool submarine... hope it will float! ;-)
[Re: Dirk]
#92699 05/12/0707:51 PM05/12/0707:51 PM