Model Boat Mayhem
Technical, Techniques, Hints, and Tips => GRP & Epoxy => Topic started by: ray t on August 20, 2010, 09:55:21 am
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Hi all. I am just starting to finish my new hull. There are a few bits of trimming required and it needs a good shine. When it came out of the mould it was pretty shinny however there were some dull areas and a bit of orange peel. So I have used some 1200 wet n dry but the results have been disastorous to say the least. The hull is now very dull and flat all over and I have no idea what to do to get a deep black gloss back.
Any ideas chaps?
Many thanks
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Thought a picture might be easier to understand what I mean
(http://i33.photobucket.com/albums/d54/big_ray_t/photo.jpg)
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Any wet and dry will always leave a flat finish, as it is taking a layer off. But it will leave a nice smooth finish, so it may be polishable back to a shine, might want to use some 2400 first, try some t-cut or metal polish, I find they bring most surfaces back pretty well. Just experiment on a non obvious bit first.
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It looks so poor because you have dulled over the high spots on the original finish - gel coat I presume.
Was the mould highly polished before you laid up the hull?
I would suggest a coat of gloss varnish. Or a recoat with the gel coat, unless that is too thick.
If you dont mind the work and the surface is hard enough, you could polish with brasso or similar.
Polishing will make it shiny, but not change any uneveness.
Good luck :-))
John
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defiantly try to sand it with some 2400 grit, and use some t-cut to buff it to a smooth finish if its a gel coat on the surface, you said you wanted a 'gloss' black finish if the buffing up does not work you have options to prime and spray it, although not the most desirable way to finish a GPR hull but it could leave you the only option if all else fails!
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I would use 1200 wet & dry, with washing up liquid in warm water, polish with T cut, I you have a a polishing mop use with cutting compound with plenty of water you will end up with a very good finish, better than the original gelcoat.
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At my disposal I have the following:
1200 wet 'n' dry
Turtle Wax Professional T9 Liquid Compound Fine
Dodo Juice Wax
Carnauba Gold Wax
Which of the following would you guys try first? I have tried them all in various orders however can not seem to get rid of the flat parts. I dont mind how much work it involes, I would just like to get it back to its original state. I mean after waxing, the whole hull is very shiny, however some parts are deep black and shiny, but other parts are shiny grey almost, if that makes any sense at all {:-{
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get a good 1200 rub down , the use the t9 stuff over the hull untill you get an even finish, then wax or buff it if required
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I would use Tcut after flatting then Fare'cla G10 extra fine grade liquid compound, used in most body shops. Do you have a polishing mop?
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I do have a mop but it seems a little big to do a small hull. Not to sure if the head would get everywhere. It is only a vheap one though (Wax Wizard) http://www.cqout.com/item.asp?id=3631398 (http://www.cqout.com/item.asp?id=3631398)
When you say T Cut, do you mean the T Cut Original in the Red bottle. There are so many different T cuts out there now its confusing (paint resporers etc).
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any fine grade t-cut will do the job
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Ray, a polished surface is simply one where the scratches and surface imperfections are smaller than the wavelength of visible light. That is, it's still "rough", but you can't see it. :-)
P1200 paper has a nominal grit size of 15.4 micro meters (I didn't know that - I've just looked it up!) and light has a wavelength around 0.53 micro meters. Old, used 1200, used wet, will get you near to that wavelength, but you'll need something finer to "polish" it.
T-cut contains very fine particles of grit and scratches off a very thin layer of paint when used on cars, and will similarly remove a thin layer of resin when used on your hull, and it should "polish" it ok - but do try going down the sandpaper grades first: it might make your job easier if you can get a finer paper than 1200.
Andy