Gelcoat Cleaner

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st599

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Trying to clear up some Gelcoat on a boat that's been out for the Winter.

Covered in tree sap, teak oil form the boat stored next door, some rust stains near the anchor locker and general dirt.

Had a go with some Y10 - didn't shift the teak oil or sap stains - sort of started to get rid of the others.

Can anyone recommend a product to a) deep clean the surface and b) add a protective layer?
 
Y10 will shift rust stains and brown stains around the waterline. For teak oil and tree sap, you might start with solvents such as white spirit, followed by cheap own-brand "creme cleaners" which are mildly abrasive. Then you need to polish to get any remaining muck off, followed by an application of wax to protect the surface.

How come the boat next door managed to get teak oil on your boat? I'd be very cross about that.
 
Y10 is just an expensive way of buying Oxalic acid, as PVB says, good for rust and waterline stains. I use supermarket own brand cream cleaner for general gel cleaning and abrasive magic sponges for more stubborn marks. Acetone may shift the tree sap and teak oil and won't damage the gel. I've found Starbright polish with teflon gives a lasting shine.
 
A mixture of white spirits and elbow grease generally removes teak oil (albeit there seem to be quite a wide range of formulae for teak oil). A kitchen scourer seems as good as anything for applying the elbow grease.
 
GrahamM376 said:
Y10 is just an expensive way of buying Oxalic acid, as PVB says, good for rust and waterline stains. I use supermarket own brand cream cleaner for general gel cleaning and abrasive magic sponges for more stubborn marks. Acetone may shift the tree sap and teak oil and won't damage the gel. I've found Starbright polish with teflon gives a lasting shine.
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I have made a £10 tub of Y10 last me 3 years. I just paint it on with a brush; it goes a long way. I agree there are cheaper ways to buy Oxalic acid but they are mostly in crystal form and even after diluting they crystalise again qucikly after appication. The Y10 route is safe for GRP and proven although I agree it is not agressive and not good for removing some stains.

Other maks, blemishes or stains could be ingrained deep in the gel coat - so I would try Y10 first and then a light polish. If the stains persist I doubt if anything will remove them ... or are there some chemists who can show me the error of my ways??
 
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lpdsn said:
A mixture of white spirits and elbow grease generally removes teak oil (albeit there seem to be quite a wide range of formulae for teak oil). A kitchen scourer seems as good as anything for applying the elbow grease.
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I'd be concerned about a scourer scratching the gelcoat. I'd use kitchen roll.
 
I find the Y10, and the homemade stuff I now use instead, dries on the hull quite rapidly in warm weather. The water pressure from the boatyard hose is not enough to shift it so I wash it off with soapy water and the green side of one of these: https://www.nisbets.co.uk/jantex-sp...&cm_mmc=PLA-_-1065064455-_-57689852332-_-F960 . Then I rinse with clean water.

My boat is 51-years old and I have been using this technique throughout the 21 years i have owned her. Her previous owner used CIF (JIF?). The gelcoat is still in remarkably good condition.
 
pvb said:
I'd be concerned about a scourer scratching the gelcoat. I'd use kitchen roll.
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Maybe we're thinking of different types of scourers. The green thingies are probably not a great deal worse than 1200 grit. You'll not get very far very quick with a kitchen towel on dried teak oil.
 
Twisterowner said:
I find the Y10, and the homemade stuff I now use instead, dries on the hull quite rapidly in warm weather. The water pressure from the boatyard hose is not enough to shift it so I wash it off with soapy water and the green side of one of these: https://www.nisbets.co.uk/jantex-sp...&cm_mmc=PLA-_-1065064455-_-57689852332-_-F960 . Then I rinse with clean water.

My boat is 51-years old and I have been using this technique throughout the 21 years i have owned her. Her previous owner used CIF (JIF?). The gelcoat is still in remarkably good condition.
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I've been using CIF (JIF?) successfully for many years as a gelcoat cleaner but it has to be the "original" type. However it is not very effective on rust stains.

Www.solocoastalsailing.co.uk
 
Many years ago when I bought my boat it had some varnish or teak oil stains on the GRP around the hand rails. I found Dilunett to be most effective in removing it.
 
I wouldn't use anything abrasive on gelcoat unless I had to. As an alternative to white spirit or other solvent, I would either or additionally use a detergent cleaner such as International Gelcoat Cleaner. I use Yachticon Anti-gilb as an alternative to Y10 since it is sloppier and easier to use, and comes in larger bottles. It is a German product but sometimes available.

As an abrasive, for something a bit more aggressive than polish, I use Starbright Colour Restorer Polish which works well on dull or stubborn areas, such as around the engine exhaust. I follow this with a wax and sealant.
 
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