I Want to Paint My Hull BLACK - Advice?

caguy · Jul 18, 2012

It would be interesting to see the affect by measuring various hulls with one of those portable heat sensors. I really don't think it is a big problem. For one, the water acts as a big heat sink. Secondly the angle of the freeboard will reflect more sun light especially during the summer when the sun is high. Thirdly here in So California where the average days run in the mid 70's on the coast has little affect on the cabin temperature. In Florida that might be a different story.
Here's an idea, buy a temperature gun on Ebay and make an entertaining video of yourself measuring hull temperatures in Long Beach.
If you want come on up to tre sheik MDR where we have a ton of boats with dark hulls.

http://www.ebay.com/itm/Non-Contact...670?pt=LH_DefaultDomain_0&hash=item3a74ae79ce

JVB · Jul 19, 2012

Go to http://masha.oversigma.com/ColorHouse/
and search for "Results" to see the results of a grade school science experiment on the affect of color on house temperature. Black runs as much as 20 degrees Centigrade hotter than white on a sunny day.

Go to a car dealer in your location and put thermometers in identical (including windows up or down and hours in the Sun) black and white cars. You can expect to see significantly higher temperatures in the black vehicle on sunny days. Better yet do the same with sailboats.

Kordie · Jul 19, 2012

I can feel a huge difference on a sunny day if I wear black jeans instead of blue jeans.

A black hull has got to be somewhat hotter. Black topsides would be terrible!

Merlin Clark · Jul 20, 2012

If the cars, houses or jeans were half submerged the result might be closer to the boat discussion.

dlandersson · Jul 20, 2012

The new Macgregor 26M's come with a black hull. Go look at one.

http://www.macgregor26.com/

Benjmin · Jul 20, 2012

finding41 · Jul 21, 2012

Talk to the manufacturer

RichH said:
Most boats that are built with dark hulls have an extra thick matting layer under the gelcoat to prevent future 'soft wrinkling' of the surface. This soft wrinkling (raised and depressed blemishes) occurs due to the extreme thermal cycling that a dark hull undergoes. The thermal cycling affects the long term cure of styrene resins (styrene used in polyester resins takes an infinite time to 'fully' cure, extra heating/cycling enhances the 'final cure'.

Before painting your hull dark, carefully seek out other Newport 28 (or any other Newport built boat) owners who have painted their hulls dark. Find out the time elapsed after the hull was painted dark and carefully examine the surface condition versus that elapsed time ... and make a decision if you want to see such similar surface distortion or whats known as 'thermal print through' of the under-layers of the laminate showing through on YOUR boat in an equivalent time frame.

Just take a walk through any boat yard and scan what those originally white but now painted dark/black/blue hulls now look like after many years of additional thermal cycling: visible hard spots, large shallow pimples, a show-though of the internal laminate roving layer ... looks like a basket weave pattern when one looks at the surface from a shallow 'incidence' (almost parallel to the surface" angle.

Indeed dark/blue/black hulls are stunning; but, keeping such boats in 'warm' venues usually results sometimes in pretty severe topside surface distortion or 'print through' ... unless there is sufficiently thick matting layer under that OEM gelcoat.
Check out other owners of Newport boats, etc. before you make such a commitment ... as a pimpled / 'printed-through' hull is quite hard to 'unload'/sell.
Most yards will have sterling examples of old fiberglass boats that were painted 'dark' and are now after few/many years in the hot sun are showing stunning 'print through'.

Its NOT a good idea to paint an originally white/light hull 'dark', unless youre absolutely sure that such a boat either by history of the build is stable in HOT surfaces or thermally cycling surfaces .... or your quite sure that the matting layer under that gelcoat is quite 'thick' to prevent such 'print through'.

I have seen things go terribly wrong when painting dark colors over light! This in the housing industry. I have seen vinyl siding that was creme color get painted dark purple. It expanded so much it looks like waves on the side of the house! Never went down either! (I would conservatively guess that it has expanded bout 5% of its original size.) I have seen white aluminum painted red and the red come off 2 years later in big sheets! Both surfaces were "somewhat prepared for painting by the owner".
It comes down to a few things. #1 the material was made to be the color that it is. (I doubt the factory even knows that. Why would they, there only making white boats.) #2 different materials expand and contract at different rates. You need to know how the base material (fiberglass hull) and the new paint reacts to higher temperatures. Especially the rate of heating/expansion!
Then PREPARATION! That's the most improtant part of the process if yoiu decide to go ahead with it. FOLLOW THE INSTRUCTIONS ON THE CAN!

Merlin Clark · Jul 21, 2012

Benjmin said:
Come to south carolina. Look at my sailboat that was painted midnight blue this past November by a professional. It looked like the most beautiful thing created on earth. One week after it was put outside in the sunlight. The paint cracked in some spots. Blisters in others. Print through in random places. I cry when I look at my boat up close. I cry when I think of the 17k I paid to have my paint job look like dog poo. I only wish someone would have warned me like I am warning you. But if you are stuck on having a dark color like I was. You will do the same thing I did. And do it anyway....

But hey here are the facts. It still looks good from 25ft away. Damn good! And anyone close enough to see the flaws is to close to my boat.

Sounds like you need to go after that "professional".
I painted my own with roller and tip brush and had none of those effects.

caguy · Jul 21, 2012

merlinuxo said:
Sounds like you need to go after that "professional".
I painted my own with roller and tip brush and had none of those effects.

What kind of paint did you use? Have you had any issues with scratching? Did you notice a temperature change?

Benjmin · Jul 21, 2012

Merlin Clark · Jul 22, 2012

caguy said:
What kind of paint did you use? Have you had any issues with scratching? Did you notice a temperature change?

I used a 1 part poly brand name "Blue Water" and while I've protected the hull I did have a scratch that I touched up. If I were to do it again, I'd spend more and get Perfection. I've seen other jobs done with that paint and it flows better than what I used. Could just be that I'm a bad painter.
The boat may be a few degrees hotter but down here (my guage) it's either "stinking hot", "not so bad" or "nice" and to be honest I haven't noticed any change below during "stinking hot". Nor have I gotten any complaints from other that sailed with me before I painted the hull.
I like it, wouldn't change it and would do it again.

I should add that the hull will have to be waxed or otherwise protected because dark colors will fade.

caguy · Jul 22, 2012

I used Perfection on the boot stripe of th Luger. I did it the same color that I eventually may do the hull. It flowed and skinned out nicely. It's been about 2 years and it hasn't faded yet. I was cleaning it yesterday and it shines as nice as the day I applied it.

Merlin Clark · Jul 24, 2012

Thanks Joel.