GRP waterline stain removal

[Skipjack]

Hello all. This is my first post here, as my usual haunt is Classic Boat, but I have an innocent question that would destroy my creek cred if I raise it there. I also apologise if this subject has been done to death here, but I have had a look round, and couldn't immediately find anything on it.

I'm still in denial about owning a plastic boat, you see, but in 1975, the auld fella bought a Dockrell 17 at the Boat Show, and she is about the best boat we ever had. She sat on the mud in Tollesbury for well over a couple of decades, but she is looking a bit tired now, the principal reason being the brown staining above the waterline (her gelcoat is white).

I bought some special gunk that did a terrific job of bringing her back to colour once, but I'm told that firm went belly-up or something, so can this community give me some distilled wisdom as to what currently available product I should seek out?

Many thanks in anticipation.

<hr width=100% size=1>Sort out those fenders! Crossplys to port and radials to starboard!

 

[bigmart]

There are loads of different brands. They are basically Oxalic Acid & bleach the stain white again. The marks will return but it works for a while. Y10 gel is popular I have used this & Starbright Hull & Waterline Cleaner.

Just be prepared to re-apply every 6-9 Months.

Martin

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[LadyInBed]

Special gunk that you require in Harpic yes, HARPIC (original) toilet cleaner.
Wipe it on neat, I use a sponge (ware rubber gloves)
You will think nothing is happening, but if you wait a couple of minutes then wipe the treated area over with a damp cloth, the dirty yellow mark will disappear.
No heavy rubbing is required.


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[jerryat]

Hi Skipjack!

As has been mentioned, Y10 is quite good and I have used it occasionally, however I think that Boatlife's Creme Cleaner and Stain Remover is easier to use (more visible, so you can see where you've been!) and extremely effective. Wet the surface, spread the stuff thinly over the affected areas, then sit down and have a beer or cup of tea. When you've inished that, wash off with water. You can use either salt or fresh water with equal effect.

All seem to be based on some form of oxalic acid, so it's really a case of which you can get most easily or cost.

Cheers

Jerry



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[philip_stevens]

A very cheap and easy application is any Bathroom Mould & Stain Remover, or Dettox Anti-Bacterial Mould & Fungus Remover.

Tea stains (in sinks) are similar to muddy river stains, and the above removers get rid of it in seconds. We use it in our white moulded kitchen sink, and the effect is very quick and effective.

Another application is Patio Cleaner - from B&Q and other outlets. I bought some GRP cleaner (KH Industries) in Aussie a while ago, and its main constituant is 10% hydrochloric acid. Patio cleaner is 8% and cleans just as well - even better if you add some CIF to the sponge or cloth you are using.

Don't forget to wear good rubber gloves.

<hr width=100% size=1>regards,
Philip

 

[Skipjack]

Thank you, gentlemen. Very useful responses. It's rather tempting to test the proprietary product against the household and guage results. I am in the lucky position of looking out at said boat as I type, so I'll go and try a trial area with bleach and get back to you later.........................

<hr width=100% size=1>Sort out those fenders! Crossplys to port and radials to starboard!

 

[William_H]

And one last suggestion is lemon juice. This is particularly convenient if you are trying to clean the stain when the boat is in the water and you also are in the water. Cut a lemon in half and press onto the stain area. Failing that any acid but be carefull. regards will

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[EdEssery]

Much cheaper to make your own as described on here previously. You need Oxalic Acid crystals, water and wallpaper paste. Search the forum for wallpaper paste to find the recipe. You can make a bucketful for the cost of a tiny pot of Y10.

Ed

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[Skipjack]

Thanks for all the help. I succumbed to an inate fear that I would end up melting the plastic if I tried to concoct a home-brew, so I got in touch with those uncommonly helpful people at Marinestore in Maldon, and they shipped me a tub of Y10 overnight.

It has brought the staining out a treat, but it has also exposed how desperate the hull is for a proper good polishing, so that is the next question: which polishing system? Why is everything a system these days?

I read on another thread that 3M do a stonking good wax. Any other ideas?

<hr width=100% size=1>Sort out those fenders! Crossplys to port and radials to starboard!

 

[bigmart]

3M is the best stuff I have ever found. Having used it I would never trust anything else.

Martin

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[Dave_Plymouth]

SkipJack

I use a product called Y10 it contains oxalic acid (present in rhubarb and buckwheat) and is really good for whitening GRP. I used it on my WHITE Dockrell 22 on shore this summer. My wife walked straight passed it thinking it was not our yacht. Y10 comes in a small tub for about £9.95 available at most chandlery stores. It goes a long way, just paint it on and wash it off about 10 minutes later. Please read safety instructions first.

Dave (www.dockrell.co.uk)