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View Full Version : Reccomended method for Gelcoat spruice up?



fender22
23-09-2007, 09:33 AM
Hi, just bought an older boat and while the gelcoat generally is in exceptional condition, in some areas it has a bit of a white opaque coating, fairly minor but enough to detract from the appearance. It's not the usual powdery oxidisation, looks more like it hasn't been washed down well after a few trips. I have used the gel coat restorer before but feel in this case it's not warranted. Does anyone have any ideas or tips on something a bit stronger I could wash it with or is light cut back car polish ok? Is car wash ok to use?

Many thanks in advance...

oldboot
23-09-2007, 10:31 AM
bearing in mind I'm no " boat expert" but

My first port of call would be a good wash with a but of rough rag like an old work shirt (remove the buttons first). you'd be surprised what a good stiff rub brings off.

Dishwashing liquid would be a safe chioce & shouldnt have any thing nasty in it.
I've always washed my cars with dishwashing liquid.

if you have a variable speed electric buff I'd be going to a refinish supplier for some micro abrasive... this stuff is finer that retail product and has no waxes or silicones in it just abrasive and carriers.
This is what panelbeaters use on modern finishes. I use this on small acrilic "craft items" and it works very well on acrilic, which is the resin in fibreglass.

the medium grade should be just fine

I get DBA brand L2 grade from MFP refinish at thornside & it costs me about $16 a litre.

go easy with it and keep the abrasive up to the pad and have a spray bottle of water for when it starts getting a little dry.

If this stuff doesnt get it gleaming gleaming gleaming..... you have a problem

if after a wash the surface is rough to touch you might want to have at it with some 1200 or finer wet & dry.... run wet......softly softly though.

you might want to put a wax or poilsh on afterward.

cheers

gavsgonefishing
23-09-2007, 09:20 PM
fender,

if your have a sander polisher with a lambswool pad, thats the go. Problem with car polishers is the colours (green, brown etc) get into the pores of the glass, making more work for you.

If the gelcoat is in pretty ggod nick as you have said, I would get a white fine cut and polish and buff it in either by hand (if you are looking at building your muscles)then buff it off. Dont be afraid of a little water to lubricate the whole affair, but remember more water less cut. The white cut & polishers can be bought at any fibreglass or marine joint.

If you want a really good finish then get the wet and dry out, probably 600 up depending on the gel coat, rub it with a block and water until all the existing shine is off (youll know what I mean when you start rubbing). If in doubt start with a higher grade, if the paper clogs easy, and there is no progress drop the grade by 200 etc. anything lower than 600 will require two gos ( eg 400 then up to 600). After that use the buffing compound with the machine (small area at a time, and dont letit dry completely). I would then machine buff the coat with water, this to me is an easy way to get rid of residue.

Think you are finished yet, forget it. Time for a decent polish, by hand or machine.

Extreme maybe, but the result is a pleaser

Livey
23-09-2007, 09:24 PM
machine buff with low abrasive compound, then car polishing wax the non coloured sort. if the glass is not too bad to start with just try thy polishing wax after a good clean.

oldboot
23-09-2007, 09:29 PM
I think gav & I are pretty close to being on the same line.... that micro abrasive I use has no colouring just white alox microabrasive.

Gav's a bit more agressive on the W&D than I would be But he's the glass guru;D ;D

cheers

gavsgonefishing
23-09-2007, 10:00 PM
oldboot spot on, it really depends on the surface you have got. 1200 is a little fine for my liking on gelcoat, great for cars but glass has too bigger pores, if it didnt, you wouldnt need to polish it;D . The dishwashing liquid thing is translated to a nuetral PH cleaner (and not much is the secret) Do not use agressive cleaners, alkaline or acid as you will do more damage than good.

How do I know, I specialise in cleaning.

gavsgonefishing
23-09-2007, 10:03 PM
oh thats another thing. Most fine cuts for glass is equivelent to about 600-800 grade, polishers are a lot higher.