Removing Streaks/Stains from GRP hull

demonboy

demonboy

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Hi all,

Our boat has been sitting in the yard for the last 18 months and we're now at the final preparation stages - washing and antifouling. Unfortunately the side of the hull has stains running from the deck to the water line and a quick scrub with detergent ain't shifting it.

We'll be polishing the boat shortly but should I be getting rid of the stains with a brush and detergent or will the polishing (with a proper polisher) get rid of these stubborn stains? They are very unsightly and need to be eliminated! How do you get rid of your stains?

Thanks in advance for any tips/suggestions.
 
Definitely do not try to polish a dirty hull, the dirt will be driven in to the surface and be very difficult to remove afterwards.

Many of the proprietary products containing oxalic acid are very effective: personally I prefer BoatLife but many work well. Many of the marks that remain after extended standing are not touched by oxalic acid and this is where Black Streak Remover is extremely useful - it does exactly what the name suggests. I have struggled with oxalic acid, cream cleaner and much elbow grease to little effect, then ten minutes with BSR overcame the problem with no effort. The one product that I never sail without.
 
Trouble is we're liveaboards, currently in a boatyard in turkey and not sure if we can get Black Streak Remover. Can you tell me the active ingredients so that I can look for a turkish equivalent? thanks

I've just been speaking to a Turk who's been spending the last week polishing his stinkpot and he recommended a product here which is actually a rust and stain remover - I believe it contains oxalic acid. This is great because I've spent the last 5 months trying to find the Turkish for 'oxalic', to no avail!
 
I only partly agree with the idea of not polishing a dirty hull. I use a hull cleaner and sometimes an oxalic-based cleaner, but often find the last of the dirt only comes out by rubbing polish well in (Starbrite). It seems to dissolve out the stains. Best thing is to experiment.
 
Ingredients...

EDTA is a common additive in detergents, but doesn't do much. The main active ingredient in Black Streak Remover is DPGME, a glycol ether used as a cleaner and surfactant. As an alternative in Turkey, if the Starbrite product isn't available, I'd look at careful use of something like an automotive alloy wheel cleaner spray.
 
Hi

you should be able to get oxalic acid from the eczane - but failing that I have seen teak wonder prducts for sale in Fethiye, (last week) - the TW wood brightener will clean grp a treat
 
Re: Ingredients...

Here in Spain I use toilet cleaner Agua Fuerte also Sulphmante which are dilute Hydrochloric acid. Effective for all rust streaks and the brown smudge that develops just above the A.F,line on a white hull. Wearing rubber gloves wipe it on, then off with sea water a few mins later
 
Re: Ingredients...

I think we're laughing with the oxalic acid now (as mentioned above, a stain remover we've discovered). Also, despite the previous post about not being able to get the Staybrite products over here (which was posted by my partner), I'm pretty confident we can get Black Streak Remover. Interesting that the eczane does oxalic acid too - good to know, thank you.
 
Re: Ingredients...

I've used Y10 but get Blue streaks where it's dried in the 10minute wait.

absiolute bu88er to remove them so may avoice the Y10 in future. Was trying to bring back the colour of the whole hull...
 
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