GRP Colour Matching

[Goldie]

I have just had some gelocoat work done on a previous repair (poorly done before our ownership) and took advantage to have the same guy attend to some very small chips plus make good where some fittings have been removed. The GRP is 'off white' and the repairs are in a much brighter white which are immediately obvious to the naked eye. The contractor claims that they will blend 'with time'. I'm not convinced - previous repairs on other boats, and this one, have been invisible from day one. the question is, how good should I expect the match to be, acknowledging that matching is a tricky task? What degree of difference is acceptable or should I kick up a fuss?

 

[neale]

A good repair will be almost invisible. Colour matching is an art and white is as hard a colour as any to match. I guess you probably get what you pay for in this respect. How did your guy compare, cost wise, to others?

 

[gjgm]

if anything, its the other way around- the new match will fade at a different rate to the old. Ok, I guess you could then reason it will match one day!
It should match now.

 

[pete]

[ QUOTE ]
The contractor claims that they will blend 'with time'

[/ QUOTE ]
Tell him that it will be the same time you settle the bill. /forums/images/graemlins/ooo.gif

Pete

 

[Goldie]

Actually Pete, that's exactly what I've done but I'm trying to establish how (un?)rerasonable I'm being. I believe that a perfect match is achievable (it's been done before!) with enough experimentation to get the right shade before application. If that takes several hours of trial attempts, so be it.

 

[Goldie]

[ QUOTE ]
I guess you probably get what you pay for in this respect. How did your guy compare, cost wise, to others?

[/ QUOTE ]
Established and reputable contractor at appropriate labour rates. This wasn't a fly-by-night operation and the bill runs into a few hundred pounds. Anyone know where I can do a course of gelcoat repairs? /forums/images/graemlins/tongue.gif

 

[neale]

Gelcoat repairs are not too difficult. Wessex do a course. Colour matching is an art that requires practice but I would expect it to be right if I paid the going rate. Obviously if it takes hours, you will be paying for hours of labour but that is down to the repairer to tell you when he quotes for the job.

 

[Poignard]

[ QUOTE ]
The contractor claims that they will blend 'with time'.

[/ QUOTE ]

I hope he's right! I repaired a long scratch in my topsides last week and, although I am happy with the fairing-in, the colour difference is noticeable.

 

[oldsaltoz]

The best tip I can pass on is:

Make sure you collect all the dust when sanding off the damaged gel coat, mix this with the new gel coat, surface layer if possible.

It will:

Make matching the colour a bit easier.

The fade rate will be closer to the old gel coat.

'Some' gel coats cure just a tiny shade lighter than mixed colour, so keep this in mind.

If you suspect you might have to sand it after curing, put two layers of masking tape around the repair area before you start, this will leave a thin film for sanding and avoid low spots.

Hope this helps.

Avagoodweekend......

 

[DavidTav]

I did some similiar repairs to my 25 year old boat recently. When I bought the white gelcoat I told the supplier that my boat didn't look brilliant white and he gave me a small amount of yellow pigment and told me to try adding only a slight trace of this to the mix. I did this and I am pretty pleased with the result.

 

[gjgm]

if you understand the basics, and there are a few links on these web pages somewhere, then you dont need a course.
As said elsewhere, the skill is colour matching.
If your gel is off white, then you ll need white gel plus black,yellow and red pigment. It tend to slightly change colour as it hardens too.
So, you start with a small jar of white, and start exprimenting with ONE TINY DROP of the various pigments, and smear the gel onto the CLEANED repair area, stil without hardener (So you can wipe it off again!).
For off white, I reckon you should get close within a couple of hours experimenting, unless you have an art background. An expert will probably take 15 minutes ! But its quite a relaxing afternoon if you like that sort of thing.
So, I m saying that you can do it yourself with a little practice and experimentation. Unless you have a very low price job, a pro should certainly be able to match it pretty close. If its just bright white, he has either used premixed gelcoat paste, or hsnt bothered to colour match IMHO.
If its blue gel, get someone else to do it /forums/images/graemlins/shocked.gif

 

[Goldie]

[ QUOTE ]
If its just bright white, he has either used premixed gelcoat paste, or hsnt bothered to colour match IMHO.


[/ QUOTE ]

My thoughts exactly. Many thanks for the tip as to colours to mix too - I wouldn't have thought of black!!

 

[Gin]

When I bought my 1983 built boat in 2005 it had a broken stanchion post moulding in the original (off)white deck.

I had Universal Boatyard repair it at what I thought was a considerable cost - £340- but to be honest I was never sure afterwards just which moulding had been repaired i.e. it matched perfectly and was, obviously, very skilfully done, therefore no complaints

 

[Billjratt]

Re the gel pigment mixing on the background hull: clean an area adjacent to the repair with oxalic etc, wax it, (to ease removal later) and mix the gel and pigments until the paste is invisible against the background. then transfer the mix to your pallette and add hardner before applying to the repair as normal. This from a retired pro.

 

[Alrob]

nice tip - will remember that one /forums/images/graemlins/smirk.gif

 

[Goldie]

Thanks one and all. What I'm hearing is that a good match should be invisible or at least, very nearly so. In that case, I'm fairly content that I'm not being unreasonable. Many thanks.