Coloured gelcoat- how to repair??

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sparkie

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Hi all, I've got some old screw holes, scratches and general wing-dings in my blue hull. Need to fill before a major cut and polish during lay-up. Only ever used white gelcoat filler before, and I'm struggling to find a blue equivalent. I've found some liquid gelcoat that's sort of the right colour (I'm not too fussy 'cos it's an old faded hull), but I can't find any ready mixed paste. Could I mix filler powder with this to make a paste? Or alternatively just add some blue pigment to a tube of white filler eg Plastic Padding? Any advice gratefully received.....
 
Have a look here...

Flowcoat/Topcoat RAL Colours (inc catalyst)- East Coast Fibreglass Supplies

This is for flowcoat*. A Dremel with a grinding bit can be used to open up cracks and clean out holes. Then clean with acetone. On vertical surfaces you need something to stop the flowcoat sagging while it hardens. I use unwrinkled kitchen foil but you can buy release film from the same supplier. Then you'll need sand paper in increasing grit fineness up to 1200 and finally some finishing compound and a polisher to make it shiny. Silverline make a good variable speed one. Small areas can be done by hand.

Farecla Profile Finish Liquid Compound
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Polyester Release film (Type A MYLAR®) - 914mm wide - 50 microns

Or you could just get some pigment and mix it in with your favourite filler.

* Gelcoat doesn't harden unless air is excluded. Flowcoat does because it has wax in it which rises to the top. If you want to put another layer on top of flowcoat you need to sand it lightly to remove the wax.
 
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its unbelievably hard to match colour, unless of course you can do it...

my Mrs is a actual "colourist " or was in a past life, she can knock up an exact match in about 3-5mins from the base colours...its amazing to watch...
adding say a pin head full of red to get that perfect match.....blows my mind...
I keep telling her she should sell it to local people (Gosport area)

just need these 2 and 20 years of skill :cool:

Gelcoat

Pigment Pack
 
I mixed some pigments a couple of years ago to match the blue grp of my hull, I made up far more than was needed so that I have a pot of it ready made for future use, the match is spot-on and mixes perfectly with the topcoat.
Thankfully the hull is blue, if t had been in the green/yellow part of the spectrum I may not have been so successful as I have a degree of colour blindness in that region.
 
Praxinoscope said:
I mixed some pigments a couple of years ago to match the blue grp of my hull, I made up far more than was needed so that I have a pot of it ready made for future use, the match is spot-on and mixes perfectly with the topcoat.
Thankfully the hull is blue, if t had been in the green/yellow part of the spectrum I may not have been so successful as I have a degree of colour blindness in that region.
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Mmmm interesting, good idea to make a pot. Do you keep it in the freezer?? I think the shelf life is only about 6 months.
 
sparkie said:
Mmmm interesting, good idea to make a pot. Do you keep it in the freezer?? I think the shelf life is only about 6 months.
Click to expand...

I don’t Keep the pigments mixed with topcoat, they are just the mixed pigments ready to mix with the topcoat when required, I don’t think the pigments have a short shelf life.
 
Remember to rub and polish a small area and check the colour against that, not faded gelcoat.

If you add pigment to white filler, you will likely end with a pastel colour. If your pigment is liquid, you may end up having to add so much that the filler becomes liquid, and does not cure well. You need micro silica to go from liquid to filler. Also called Carbosil and Aerosil. When you mix in silica you also get tiny air bubbles. It helps to leave in a closed jar for a day or two.

If match colours and want to keep for some time, put it in a clean glass jar or tin with not too much air space, not a plastic container, and store it cool. It will not last for ever, but significantly longer than the often quoted 6 month. Before you use it next time, make a small cure test, to see if it has survived.
 
Get along to a GRP shop ... and you can buy Gelcoat plain white and pigment separately.

The trick is to mix a small amount and get to near colour - dab a bit into the hole to be filled. Not right ? Adjust pigment next dab ...

Its impossible to match an over counter original colour as it had faded .. abraded ... all sorts affected its shade. Like car repairers - you have to artificially arrive at the shade by use of pigment.
Not an easy job.
 
Refueler said:
Its impossible to match an over counter original colour as it had faded .. abraded ... all sorts affected its shade. Like car repairers - you have to artificially arrive at the shade by use of pigment.
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Then, as the new stuff fades, the colour changes, so it no longer matches. ISTM that the best you can do is get it about right and go sailing. Or flowcoat/paint the whole damn thing and it'll be perfect - until you get it wrong coming alongside.
 
Some good youtube videos on colour matching.

Did 4 screwholes recently with an appropriate filler, topped with flowoat from ECF and a bit of pigment, after watching some YouTube - came out surprisingly well.
 
I've repaired various old screw holes and patched where I've replaced old instruments.
I bought a RAL code colour card from eBay for about £7.50, got the code, with bit of help from friends, just to check that my old eyes weren't playing tricks. Bought a repair kit from East Coast Glass Fibre, it had all the stuff I needed and more.
Patched the holes, RAL 1090 Ivory White, on a 2007 cockpit, yes, I know white is easier than blue, initially I could see the patches, but by the end of the season, I can't see them.
So at least for Ivory White the natural blending caused by 6 month of Scottish UV, brought the colour in line.
Now I don't worry if I can just see the repair immediately after it has been completed, natural weathering over a summer season seems to make the match.
 
Stemar said:
Then, as the new stuff fades, the colour changes, so it no longer matches. ISTM that the best you can do is get it about right and go sailing. Or flowcoat/paint the whole damn thing and it'll be perfect - until you get it wrong coming alongside.
Click to expand...

Painting is fine ... till year after and all those mis-matched areas start to show .... even before that - the joints / imperfections all catch light ... some show up even worse than not painted ....

But your point taken.
 
Ian_Edwards said:
I've repaired various old screw holes and patched where I've replaced old instruments.
I bought a RAL code colour card from eBay for about £7.50, got the code, with bit of help from friends, just to check that my old eyes weren't playing tricks. Bought a repair kit from East Coast Glass Fibre, it had all the stuff I needed and more.
Patched the holes, RAL 1090 Ivory White, on a 2007 cockpit, yes, I know white is easier than blue, initially I could see the patches, but by the end of the season, I can't see them.
So at least for Ivory White the natural blending caused by 6 month of Scottish UV, brought the colour in line.
Now I don't worry if I can just see the repair immediately after it has been completed, natural weathering over a summer season seems to make the match.
Click to expand...

I've always found Black and White - the two worst colours to match.
 
Andy from Boatworks Today recommends using RAL colo(u!)r charts to match dark colours.
Gelcoat Color Matching Part 1 | Boatworks Today

For dark colours you want to add.the pigment to clear gelcoat, not white.
ive always bought gel coat and pigments from East Coast Fibreglass supplies. They have a huge range of gel coat and pigments.
No connection, just a happy customer. They sell the colour cards too.
 
I have a dark green Hull. Two years ago I had a anchor chip on the bow. I mixed acrylic paint to colour match and then added epoxy 2 part clear.. Was meant to be a temporary fix. Two years later in the Turkish sun of nearly 10 months a year of sunshine up to 42c it still matches.. The cream coach roof chip didn't last as well ?
 
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