A few years ago my boat was badly stained by an oil spill in the harbour. Most of the time Cillit Bang left on for 20 min or so then washed off will remove any staining, but this was not responding at all.
I spoke to our local glassfibre repairer who said he could fix it, and he did.
He started by sanding the whole boat down with 120 grit sanding sheets (I was horrified), then he used 400 grade wet & dry followed by 600, 1000, 1200, G3 and finally wax.
Result - the boat looked like it had just come out of the mould! Brand new! He says that most people don't realise how hard and thick gelcoat is, and never cut it back hard enough to remove the oxidized layer. Ok for him though, he could re-gel it if he went too far.
I've been a bit less cautious with the compound since then though and she still gleams.
This lot supply most GRP products at reasonable prices and give advice if you e mail them with a problem.Plus they have some good downloads.....
http://www.cfsnet.co.uk/
...since I got accused of spamming on another forum recently when posting a link I will point out that I have no connection with this firm.
They do a gelcoat restoring wax finish,somewhere on the site,but I would think you need to go the route already advise and either G3 or wet'n'dry back and then use some kind of polisher to get the finish back.There is a bit in haynes about it....just not much !
I used 3M marine fiberglass restorer and wax (all in one) from a chandlers, on mine. 500ml bottle was £11-75 a couple of years ago. Applied using mutton cloth, turned frequently, it worked well, if a little slowly. Took me a couple of hours, between brews.
Pete.
------------- Don't panic!
Hit it with a pointed stick!
Nostalgia's not what it used to be.
can i just say for information only this treatment above is only for GRP,glass reinforced plastic,(rough to the touch on the inside) if its smooth it is just plastic and will requires a different kind of polishing.
------------- the only silly question is the one you do not ask.
Good point Michael!!! I had totally overlooked that,plastics are another ball game entirely,even so,my link is still relevent as the company deal in plastics too.
I have had some success with solvent cleaner for UPVC window frames,BUT !!!! its all too easy to melt plastics or deform and degrade with the wrong cleaner.
I reckon having a look at the van manufacturers site and maybe contacting them,would be a good idea.You could then find out EXACTLY what the material the panel is made of actually is,and proceed acordingly.If that doesnt work out,checking the inside surface of the panel will let you know : rough = GRP.....smooth = plastic....broadly speaking.....