Hull stain

[mick]

My otherwise beautiful (white) hull has a nasty stain from the trickle of water that comes out of the anchor locker drain hole. I’ve tried oxalic acid (10%) and various other things but nothing has shifted it. Any suggestions?

 

[[70521]]

Oxalic acid works every time for me. Did you add it to hot water? Leave it long enough to act?

 

[davidej]

Oxalic acid works every time for me. Did you add it to hot water? Leave it long enough to act?

Mix a bit of wallpaper paste in and apply the jelly to the stain.

Keeps the oxalic acid in contact much longer

 

[mick]

I did all the right things with the oxalic acid but no joy. It works on all other stains but not this one.

 

[pvb]

I did all the right things with the oxalic acid but no joy. It works on all other stains but not this one.

For stubborn stains, the oxalic acid solution needs to be warm.

 

[johnalison]

The stain from the anchor locker is presumably rust. This can be very obstinate compared to the usual hull yellowing but there is little alternative to persevering with oxalic acid or one of the proprietory preparations.

 

[Fr J Hackett]

The action of the oxalic acid is to convert the iron oxide ( insoluble) to iron oxalate (soluble) if the stain has been absorbed into the fibreglass it will take a time for it to leach all the iron stain out. The wallpaper paste trick might work but you need the oxalic acid as wrong as you can get it try making as strong a solution as you can soak a cloth in it and then apply it to the hull with a polythene backing and tape then leave it.
Oxalic acid is poisonous so wear gloves and keep it of your skin as it will be absorbed and don't drink it, having said all that it is not a deadly nerve agent and reasonable precautions are more than adequate.

 

[paulajayne]

IronX or Wonder Wheels (hot wheels).

https://groceries.morrisons.com/webshop/product/Wonder-Wheels-Hotwheels/286881011

http://www.cleanyourcar.co.uk/engine-and-exterior/carpro-iron-x-500ml/prod_726.html





The stain is from ferrous materials from anchor.

 

[Marine Reflections]

Post up a picture of the stain.

It's probably a stubborn animal, by the sound of things just scale.

 

[Foolish Muse]

On & Off cleaner is really good at removing rust. I've used it many times.
http://crc-canada.ca/marine/cleaner-degreaser/on-off-hull-bottom-cleaner-3-785-liter.html
But it will eat through your nylon jack lines real quick!!!

 

[Momac]

If Oxalic doesn't it shift it try Harpic.
https://www.therange.co.uk/househol...ing-products/harpic-power-plus-citrus/#200503

 

[capnsensible]

Ive used Y10 loadsa times for similar. Works a treat but cant get it where I live now......

https://seamarknunn.com/acatalog/y10-stain-remover-883.html

No doubt lots of people have their own favourite homebrews, but Y10 does it easily.

:encouragement:

 

[oldharry]

Ive used Y10 loadsa times for similar. Works a treat but cant get it where I live now......

https://seamarknunn.com/acatalog/y10-stain-remover-883.html

No doubt lots of people have their own favourite homebrews, but Y10 does it easily.

:encouragement:

+1 for Y10 - was about the only thing that soved a careless moment with an angle grinder spraying iron filings unnoticed (well, not until after the boat had bee left a while during a wet spell!) across the GRP.

 

[BotleyBuoy]

It might be worth reading this old thread as well

http://www.ybw.com/forums/showthread.php?86864-Oxallic-acid-confession-(-How-stupid-I-was!)

 

[Scubadoo]

Try vistal, great at removing stains and in general putting the shine back in the gelcoat.

https://www.vistalcleaningproducts.co.uk/boat_cleaning.htm

Also sold in force4.

 

[mick]

For stubborn stains, the oxalic acid solution needs to be warm.

As I said, I did all the recommended things.

 

[mick]

Thanks for suggestions. I’ll let you know how I get on.

 

[Pords]

I use good old pink stuff which is great on stubborn stains and cleaning. Friend of mine had a rust stain on his moody and had tried everything to get rid but wouldn't shift. Gave him a tub and hey presto. And all for £1 from the pound shop. I ended up buying all of them in stock at my next visit and taking down the club due to the numbers of people who wanted some.

 

[Little Dorrit]

All advice is good. If you do decide to try again with Y10 try also heating the surface before application using a steam cleaner.

 

[Marine Reflections]

In the absence of pictures...

The problem is at the height of the "above surface contaminate', it has arrived from a constant build-up of water. This usually means a build up of TDS, (Total Dissolved Solids) that rear their head in the form of scale sitting well above the surface.

An oxalic treatment would be the right choice, but may only deal with the first few pages of the yellow pages.

You would either need to continue dealing with sections of yellow pages at a time or switch to something more aggressive to deal with the whole book before you get back down to the raw gel-coat.

A specific 'de-scaler' is the right choice here.