Restoring the colour & shine on old GRP?

[bluedragon]

I've searched through the forums posts on this topic (and there are hundreds!) but I'm more confused than ever about the best products for a) removing a dull oxidised surface b) protecting it afterwards. Many recommended products seem to be "cleaners" to remove stains. Many posts also say don't use abrasive pastes...but I don't see any alternative. Like T-Cut on cars, if the gelcoat is badly oxidised, then it has to be abrasively polished to get back a shiny surface. Surely to key to this is to do it as infrequently as possible (to preserve gelcoat thickness) and then coat with a wax or some other protective finish that will fill any micro-scratches, inhibit further UV / oxidative attack and dirt ingress? Does anyone have a definitive answer to this? There are zillions of products in every chandlery that promise the earth...but which really work??

 

[BrendanS]

The two brands that get recommended over and over as really working to cut back dull gel coat are Farecla and 3M.

Personal experience of 3M upholds that.

 

[bluedragon]

What's the name of the 3M product? Wasn't obvious on their website. Thanks.

 

[bruce]

poly glow is the easiest, good scrub to remove 'soft surface' and several coats of poly glow. stuff soaks into surface and additiional layeres bring up the shine. perhaps as many as 6/10 coats to do it. will seal in dirt left before application. much like liquid kitchen floor was, just wipe on, dries in minutes, keep adding till it shines. works in florida sun, so should work in your part of the world.

 

[BrendanS]

Have a look here. Everything you'll ever need to cut and polish gelcoat
Click Here

Even better, call Peter Furby of 3M marine products - 07770 284 926 , and ask for his advice. He'll tell you what you need, and how to use it. V helpful guy.

 

[bruce]

buffing is prob the best way to go, unless your boat IS old and buffing may go thru the gelcoat...

 

[Pete735]

You have asked about restoring the colour and the shine but you have omitted to say how old your boat is and that may be very relevant.

At the risk of being contentious, I doubt whether any of these products will restore the colour on a boat that that has taken many years of uv damage. I am sure they are all perfectly good for bringing up a shine. I say this having owned a boat all of 3 months and having a limited knowledge of both GRP and paints. Logic tells me that all paints /pigments fade from uv over time, car paint does so why not boat paint?

My boat is 25 years old and generally in good shape but the colour is very dull and listless. I have farecla and can polish it fine, but change the colour? No way. I intend to repaint the hull (above waterline) with a 2 pack polyurethane, I'm not sure yet whether to do the deck or not.

 

[Cobra25]

Just been introduced to Wipe Out - works v. well simple to use £10.50 for one container should last two years I am told. Will try it on yellowing at waterline tomorrow if weather permits. Need to polish after though.

 

[ianwright]

Dead easy, Wash the hull well, sugar soap is good, rinse and let dry. Then working on an area about 3 ft on a side wipe on Owatrol, count twenty, wipe it off. That'll do it until you are ready to give it a coat or two of a good 2 pack poly.
Cutting back with farclea or t-cut is just for when you are tarting up a dull hull for sale.
IanW

 

[bluedragon]

The boat is 35 years old, and actually colour restoration as such is probably not the issue. It's getting rid of the dull oxidised surface, which itself improves the colour. Cutting back with polishing compound will achieve this, but what will best protect it afterwards? That's perhaps the biggest dilemma...and is there a combined cutting / protecting product that will do this in one shot?

 

[BrendanS]

No such thing as a one shot. Needs cutting then protecting. Give Paul Furby a call, you won't regret it.

 

[heerenleed]

As many have said, you need to buff and to seal. But we have often tried this on older boats, both our former Nicholson 35 and our actual Nicholson 48 and we found it eventually a complete waste of time. The "new" shiny surface won't shine for much over a month, as the gelcoat really is to old and keeps letting all kinds of dirt in.

Our final solution always turned out to be a lot less of a problem than we thought beforehand: repainting...
It's the only treatment that will really restore the boa't's looks.

The only awkward thing is sanding. The last time before painting you should use waterproof fine sanding paper (grain 280 or above) and do it by hand, no cork block, as you will feel if there are any spots that are not smooth enough..

When the sanding is well don, the actual painting is not extremely difficult and very very rewarding.
We used Double Coat by "De IJssel". If you wish to receive any specific info, PM me

cheers and good luck

 

[bluedragon]

Thanks everybody. I really want to avoid painting so I'll get some advice from 3M as suggested.