Blue hull

c and c of the sea said:
It's a difficult decision.
You don't really know how well the hull has been looked after by previous owners.
Has the hull been polished before the viewing.
A few years down the river will you end up with a blue hull which looks tatty and un cared for and not appealing to potential buyers.
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Well, my 2004 boat has some red gelcoat. Even worse for fading than blue or black, No UV orotectant wax has helped ( I've tried a lot !), I've cut/ polished it every year, it looks gorgeous for a while then it fades, I can literally cut/ polish it at home (not on the water) and 3 weeks later on the parts facing west it's fading. It it's manufacture, there have cllearly been different lots of red gel coat used; when polished, indistuingishable, but when subjected to UV, there are clear demarkation lines visible !
 
OK, my observations. My supplier had 900 shades of white. But they still got asked for another one.

Colour i.e. pigment, changes the properties of plastic, in my case PVC. Contrary to belief, or marketing hype. PVC is what they make windows out of. PVCP or PPVC ( If ever the initials were invented) is PVC with added Plasticisers. Which makes it bend, for a hose pipe or whatever.

PVCU or UPVC, is just marketing hype. It means Un Plasticised PVC, Which is what it was, before you wanted it to bend.

With our automatic circular saws, it was very obvious how different colours produced different saw dust, mostly, the darker the colour, the softer the plastic and easier to scratch. White being the strongest.
 
GrahamHR said:
Well, my 2004 boat has some red gelcoat. Even worse for fading than blue or black, No UV orotectant wax has helped ( I've tried a lot !), I've cut/ polished it every year, it looks gorgeous for a while then it fades, I can literally cut/ polish it at home (not on the water) and 3 weeks later on the parts facing west it's fading. It it's manufacture, there have cllearly been different lots of red gel coat used; when polished, indistuingishable, but when subjected to UV, there are clear demarkation lines visible !
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In my early years in plastics, we made some colour matched products for Silent Night. They looked like a very good match. But once in day light, they went from cream to pink!! So that needed mending.

To protect against UV light, more pigment is added. This is fine for white. But in colours, it can effect the structure.
 
MapisM said:
Pigments as UV stabilizers?!? Never heard of that.
Aren't you confusing them with HALS, by chance?
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Dunno. We just extruded plastics for our own products. Mostly UV was not an issue. The suppliers made what we wanted. Have you ever heard of HALSUPVC. ??

The issue is about whether colour alters fading. My observations are, yes it does and it alters the strength of the material.

In our case it did not matter. But on a boat???
 
Ops, I'm afraid we are at cross purposes on that.
You spoke of your "early years in plastics" (of which I also had some), and I didn't notice that in your previous post you were actually talking specifically of PVC.
HALS are instead used in polyolefins, which are the main applications for light stabilizers.
Otoh, also in PVC, pigments are only meant to colour the stuff, not to protect it against UV, IIRC.
I see your point re. fading being affected by colour, anyway.
To my knowledge, this is true in principle for any plastic material, though to various extents.
 
MapisM said:
Ops, I'm afraid we are at cross purposes on that.
You spoke of your "early years in plastics" (of which I also had some), and I didn't notice that in your previous post you were actually talking specifically of PVC.
HALS are instead used in polyolefins, which are the main applications for light stabilizers.
Otoh, also in PVC, pigments are only meant to colour the stuff, not to protect it against UV, IIRC.
I see your point re. fading being affected by colour, anyway.
To my knowledge, this is true in principle for any plastic material, though to various extents.
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Yes, that is what I said, colour alters plastic. It did not matter to us. But it could be seen. Different types of light can change the colour. This we had to mend.

But as I said, colour also effects plastics performance. Probably to do with whatever is in the chemical mix
of the colour. Maybe there has been little research done into pink boats. White ones seem to stick together. It is just other colours that have problems. Bit like Cancer, more research needed. Popular ones are mostly mended
 
I have a blue hulled 2001 boat , I understand that the gelcoat was less stable then and soon afterwards changed to a more colour stable system.

My boat spent 6 years in Portugal but well polished every year. ( I know that it would have lasted longer if it had been polished by previous owner and myself every month religiously it would have been better but there are many other things in life I prefer to spending my time eternally polishing a boat such as using it).

It got to the stage after 10 years old , a full cut and polish and six weeks later it looked like it had never been done, especialy in the stern area where the sides are more vertical and the transom which slopes away.

Last winter I had the hull sprayed with Awlgrip and the coloured grp sections of panels on the topsides I had vinyl over laid it now looks very good.

The worst colours are red, maroon and green then blue for fading.

This is my fourth blue hulled boat and they look great when relatively new, If I commissioned a new boat I would have it in white and vinyl wrap it for the first five years then unwrap it, that would really confuse friends.
 
c and c of the sea said:
It's a difficult decision.
You don't really know how well the hull has been looked after by previous owners.
Has the hull been polished before the viewing.
A few years down the river will you end up with a blue hull which looks tatty and un cared for and not appealing to potential buyers.
Click to expand...
No, I dont think so. As a layman if you look very carefully over the hull, especially fender areas and the rear quarters, you can see if there are tiny white specks showing through. Or get a Pro to come and check it out if it worries you.
I certainly wouldnt be put off just bcz the hull is blue.
Compounding isnt necessarily super agressive, it is just more agressive than a polish. Imagine the gel surface is like a piece of 80 grit sandpaper.. you will never get a good permanent shine unless you smooth that down to sheet glass-like finish. That achieved, you dont then need to do that very often- if the surface is like 1200 grit sandpaper, you would use polish (grades as an illustration here!).
However, you do indeed have a problem if the blue gel is see-through thin, bcz you cant re gel large areas, which is why people then paint.
 
You make it sound very black and white. In a way it is.
Everything can be sorted out at a later date be it harder polishing, painting or vinyls. But I need to take this into my decision now.
On another note I see you have a windy khamsin. Does that have a blue hull.
 
The typical broad blue stripe, yes, not the whole hull.
IMHO a blue hull is a little bit more problematic than a white one, and if it is an ex-Med boat, the UV has usually caused more damage.
My blue is a bit like the photos of the S/S in this thread... but I have also seen boats where someone has blitzed the fender scuffs far too hard and more or less eaten through the gel in places.
So, in conclusion, there is no reason to be over concerned over a blue hull... just check it over carefully.. plenty of other problems with a boat too ;) I wouldnt expect to see a problem on anything under at least 5 years old , and maybe 10+ on a premium boat kept in UK. As suggested, I am sure there is a local yard gel man about, so give him £10 to look over the boat if it worries you.
 
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