Oxalic acid

[rigi36]

The yellow stuff near the waterline did not come off with normal scrubbing. Is it worth giving it a go with Oxalic acid?

 

[TamT]

Yes

oxalic acid will likely shift it

 

[VicS]

Oxalic acid will almost certainly remove it.

Y10 from your chandler is based on oxalic acid...... and chandlery prices.

If you have any in the kitchen cupboard it's worth giving Cillit Bang Grime and Lime a try

 

[rigi36]

Thanks both.

Tried Fairy Power Spray without much luck.

I've ordered some crystals so will make up my own solution.

 

[VicS]

Thanks both.

Tried Fairy Power Spray without much luck.

I've ordered some crystals so will make up my own solution.

Fairy Power Spray is a degreaser, like Cillit Bang Grease and Sparkle

Lime and Grime is an acid limescale remover. Sulphamic acid IIRC.

 

[MM5AHO]

Make up a solution of oxalic acid from Ebay (where its cheap) and put fairly liquid in it - quote a bit, about as much as the water used, and you'll have a great scum remover.

 

[Vara]

Any oxalic potion is not terribly good in low temperatures, need at least 10°C, for it to work properly.

 

[MM5AHO]

Any oxalic potion is not terribly good in low temperatures, need at least 10°C, for it to work properly.

Seems to work for me in Scotland.
Its either time or temperature. We don't have the temp here!

 

[lampshuk]

I just got some oxalis acid on eBay (very cheap) and made it up to the concentration on the label, just with water. It cleared up the yellowish waterline stain (not as bad as that in your photo) very quickly. Unfortunately, it did nothing to the oil-stain (looks like the result of coming alongside a dirty fender) on the hull, which what was what I was trying to shift.

Is this worth trying with a stronger concentration? Or mixing with fairy liquid/wallpaper paste to keep it on site.

I did notice that it loosened and blistered the poorly-painted boot topping, too. In my case I don't mind, since it really needs to come off anyway.

 

[alahol2]

Unfortunately oxalic acid won't do anything against black oil/exhaust stains. The only thing I've found to get those stains shifted is rubbing compound (Farecla g4(?) etc). I'm surprised oxalic has any effect on your boot topping, I regularly overpaint the boot top with oxalic without any sign of damage.

 

[lampshuk]

... I'm surprised oxalic has any effect on your boot topping, I regularly overpaint the boot top with oxalic without any sign of damage.

The BT paint had been poorly applied in the first place, so I think the OA was just the final straw. It didn't strip it per se, just made it flakier.

I was dead impressed with how white it made the hull, though. In fact, I had not realised there was a stain until drips from the bits I was tackling showed up bleached against the slightly yellowed waterline.

 

[Corribee Boy]

Oxalic acid certainly shifts those stains, but I'm still trying to prevent them reoccurring. I've tried most forms of boat wax and polish on the market, but while they might slow it down, it's usually back within weeks.

Funnily enough, each chandler I speak to has 'just the stuff' but it's never lived up to it's claims, let alone it's price tag! I'm fed up with drawing blanks.

Does anyone have any interesting/ tried and tested suggestions?

 

[alahol2]

I was dead impressed with how white it made the hull, though. In fact, I had not realised there was a stain until drips from the bits I was tackling showed up bleached against the slightly yellowed waterline.

Yes, that sometimes happens on mine, I now just go over the entire hull to make sure I don't get patches.

 

[Bertramdriver]

Yes, that sometimes happens on mine, I now just go over the entire hull to make sure I don't get patches.

Standard T Cut will rub off oil and rubber stains at half the cost of the chandlers offering.
If you can't stop the grime returning I suggest two possible approaches
The first is to clean, polish and then rub down with raw lanolin. The grease puts an inert layer between the surface and the sea water.
The second is to clean polish and then rub down with RAINEX water repellant. Same as above but a synthetic silicon coating vs the lanolin organic.
If you're really keen you could one side with each and publish the results for us.

 

[Corribee Boy]

Ooh! I feel another (expensive) trip to the chandlery coming on! Either that, or I'll rub the boat down with one of my sheep.

I did post a query about stopping the yellowing a while ago and someone asked me to publish the results - I was waiting for a positive result, and so far, am still waiting.

Thanks for the tip, though, and I'll give it a test when I launch.

 

[Bertramdriver]

Try eBay
Tin of Lanolin £5, bottle of RAINEX £10

 

[Corribee Boy]

Even better! Thanks