Removing black marks from GRP

sgr143

sgr143

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[Apologies for asking what probably is elementary... but as a newbie, I find there's a lot of "obvious stuff" that I just don't know!]

I'd like to clean up the exterior topsides of my Westerly Merlin, where there are quite a few black scuff marks, from shoe soles I guess. What's the best way of shifting these without damaging the finish on the fibreglass? I'm nervous about using any kitchen-cleaner type abrasives / chemicals in case they attack the finish. So is it just soap, water and elbow grease, or is there anything a bit less effortful that can safely be used?

Thanks, Steve
 
Id try petrol with all the obvious cautions.or White spirits neither will be aggressive on grip and evaporate quickly.
Unless you have a really shiny new gelcoat I would not be overly concerned about mild abrasive creams.
I find the magic eraser sponges are great for shifting difficult marks. Slightly abrasive but unless it's on an immaculate shiny surface it won't damage it.
 
Cream Cleaner is excellent for all difficult cleaning jobs on hull topsides and deck. It is mildly abrasive but can be used diluted. It is also very good for stainless steel stanchions, bimini frame, etc. We also use it on the dinghy.
 
vyv_cox said:
Cream Cleaner is excellent for all difficult cleaning jobs on hull topsides and deck. It is mildly abrasive but can be used diluted. It is also very good for stainless steel stanchions, bimini frame, etc. We also use it on the dinghy.
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Yup, Cif or supermarket cheapy version.

Another product that is good for removing black marks, polishing GRP and for a super shiny finish on Stainless is 3M Finesse It, it will also remove scratches from acrylic. I recently bought a handheld from Ebay that turned up with a scratched screen, it came up like new.
 
Thanks for the suggestions - as it happened, my "fixing-up" day yesterday got absorbed in doing electrical stuff rather than polishing, but I'll give these a go next time.

Steve
 
Cif and some others are abrasive, and the OP is right to be cautious. Solvents such as white spirit are probably the right place to start, I agree, and I always have a small bottle in the gas locker. Many marks will actually come off with polishes, and even waxes, and I find that some of the worse ones will clear with Starbright Colour Restorer polish.
 
johnalison said:
Cif and some others are abrasive, and the OP is right to be cautious. Solvents such as white spirit are probably the right place to start, I agree, and I always have a small bottle in the gas locker. Many marks will actually come off with polishes, and even waxes, and I find that some of the worse ones will clear with Starbright Colour Restorer polish.
Click to expand...

They are abrasive, but not like sandpaper! The abrasive content is extremely fine and will no visible damage to gel coat. Brasso is another product with mild abrasive content, cleans almost anything without doing any damage.
 
vyv_cox said:
They are abrasive, but not like sandpaper! The abrasive content is extremely fine and will no visible damage to gel coat. Brasso is another product with mild abrasive content, cleans almost anything without doing any damage.
Click to expand...
Cif will take the shine off good GRP, whereas polishes will create a shine with microscopic abrasions, as will Brasso. With new GRP I prefer to use wax on its own.
 
The 3M Finesse It is mildly abrasive, but will not only take the black marks off, it will leave the GRP very shiny. Like i said, it's good enough to take scratches out of a handheld screen, leaving it looking like new. It's used in automotive refinishing for hand or machine buffing of paint. Also brings weathered headlamps back to as new condition.

No connection with 3M :)
 
I actually just spent the last 2 days doing this after having walked diesel and other muck all over the topsides in a bit of an emergency! It left black/grey sole marks all over the deck.

By hand in this heat, it was a bit of work. I guess it has taken me 4-5 hours to do the topsides, cockpit and stern (24 footer). I bought some 'heavy duty' Starbrite GRP cleaner and wax 'all in one' from my local shop. It's a mild T-Cut, cleaner and wax. It has certainly done the job and I obviously got the benefit of waxing it up ant the same time. Not cheap at £30 for about 750ml (maybe cheaper elsewhere), but I've plenty left so it'll last me a couple seasons I think for sure.
 
PaulRainbow said:
Yup, Cif or supermarket cheapy version.

Another product that is good for removing black marks, polishing GRP and for a super shiny finish on Stainless is 3M Finesse It, it will also remove scratches from acrylic. I recently bought a handheld from Ebay that turned up with a scratched screen, it came up like new.
Click to expand...

Theer seem to be all sorts of products labelled "3M Finesse It", ie discs, pads, liquids. What's best for say acrylic?
 
jwilson said:
Theer seem to be all sorts of products labelled "3M Finesse It", ie discs, pads, liquids. What's best for say acrylic?
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This one : http://www.ebay.co.uk/itm/3M-Finess...hash=item19c5488afe:m:mQSlb1YFuyac420PiiDVJSA

I've always had some onboard for doing GRP, but have recently used it on some acrylic. The cover over my engine instruments was so weathered you literally couldn't read the instruments. The forward deck hatch was so badly scratched and weathered you could barely see through it. Iightly sanded them and then polished with Finesse It. The instrument cover has come up almost as good as new. The hatch still has a few scratches, but is 100% better. The scratched screen on my handheld looks absolutely as new.

I've still got a deck hatch to do, i'll take some pics and post them when i do it. Won't be just yet though.

My stainless sinks and kettle have a mirror finish.

I've just re-varnished the woodwork in the heads. I carefully took the brush marks out with some ultra fine Scotch Brite and then polished it and it looks superb, like a factory sprayed job.
 
vyv_cox said:
They are abrasive, but not like sandpaper! The abrasive content is extremely fine and will no visible damage to gel coat. Brasso is another product with mild abrasive content, cleans almost anything without doing any damage.
Click to expand...
+1 also it's what i use to remove scratches from my crash helmet visor's and motorcycle wind screens.

Works like magic, if stinks a bit mind, best wear the marigolds abd that comic 'nude lady' apron you got last xmas ;).

As an aside, you never see duraglit much anymore?

Alan
 
PaulRainbow said:
This one : http://www.ebay.co.uk/itm/3M-Finess...hash=item19c5488afe:m:mQSlb1YFuyac420PiiDVJSA

I've always had some onboard for doing GRP, but have recently used it on some acrylic. The cover over my engine instruments was so weathered you literally couldn't read the instruments. The forward deck hatch was so badly scratched and weathered you could barely see through it. Iightly sanded them and then polished with Finesse It. The instrument cover has come up almost as good as new. The hatch still has a few scratches, but is 100% better. The scratched screen on my handheld looks absolutely as new.

I've still got a deck hatch to do, i'll take some pics and post them when i do it. Won't be just yet though.

My stainless sinks and kettle have a mirror finish.

I've just re-varnished the woodwork in the heads. I carefully took the brush marks out with some ultra fine Scotch Brite and then polished it and it looks superb, like a factory sprayed job.
Click to expand...
 
Scuffs will come off with Magic Eraser. No chemicals no abrasion. Brilliant stuff. I get mine from Robert Dyas but some supermarkets do their own. It is a melamine sponge that you wet and rub off the marks.
 
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