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How do I Get Rid of Hull Stains?

Posted: Jan 11th, '18, 21:01
by SimonP
After our week-long trip around the Gippsland lakes we came back with the hull stained browny-yellow especially at the water surface level
It's quite resistant to simple soap and pressure washing, but comes off with a hard scrub with kitchen creme cleaner, which is mildly abrasive
Should I be fussed about it and put in the elbow grease every year, or will it likely come off with a few vigorous sails in the salt water of PPB?

Re: How do I Get Rid of Hull Stains?

Posted: Jan 11th, '18, 21:11
by Albin57
Oxalic acid cleaner is the solution to get rid of stains.
You might find it where you can shop the brand of Diggers?

Re: How do I Get Rid of Hull Stains?

Posted: Jan 11th, '18, 21:19
by impulse
Recently started using this and I'm quite impressed.
https://www.whitworths.com.au/kleen-a-hull-1l

Re: How do I Get Rid of Hull Stains?

Posted: Jan 11th, '18, 21:33
by SimonP
Interesting that both solutions convert iron stains
Is that what the brown stain is? I thought it might have been tannin from all the tea-trees
I note that Kleen-a-hull has phosphoric acid, which is also in Coca-Cola (which we used to convert the surface rust on girders when we built our house) and is much cheaper

Re: How do I Get Rid of Hull Stains?

Posted: Jan 11th, '18, 21:49
by Albin57
I think the stains is humus, the brown/yellow water says so.

Re: How do I Get Rid of Hull Stains?

Posted: Jan 12th, '18, 15:49
by Sue H
We wash the hull after pulling the boat out with hull wash stuff (soapy) then wipe the stained area with lemon juice... wait until just about ready to put the covers on and wash again with fresh water....seems to keep much of the staining at bay during the season then of course we use the heavy duty acid type hull cleaner during the maintainence week before giving the hull a polish...
The lemon juice (acidic) seems to get rid of the light staining on the week to week basis of use..and we just purchase the bottle of lemon juice from the supermarked and apply with a chux/kitchen wipe .
Cheers,
Sue

Re: How do I Get Rid of Hull Stains?

Posted: Jan 12th, '18, 17:26
by impulse
SimonP wrote:Interesting that both solutions convert iron stains
Is that what the brown stain is? I thought it might have been tannin from all the tea-trees
I note that Kleen-a-hull has phosphoric acid, which is also in Coca-Cola (which we used to convert the surface rust on girders when we built our house) and is much cheaper
Phosphoric acid probably better for you than coke too.

Re: How do I Get Rid of Hull Stains?

Posted: Jan 12th, '18, 17:50
by MoodyBlue
Both Oxalic Acid and the Phosphoric acids clean hulls very well, but you have to keep it off the trailer or it eats away at the galvanizing.

Re: How do I Get Rid of Hull Stains?

Posted: Jan 12th, '18, 17:58
by INMA
Fibreglass restorer.

Re: How do I Get Rid of Hull Stains?

Posted: Jan 12th, '18, 20:02
by Ukuri
Bang for buck, RANNEX.
Phosphoric Acid rust converter from most good, and bad, hardwares.
For the hull dilute about 5:1 and just wipe it on.
Full strength to remove rust from stainless steel.

Re: How do I Get Rid of Hull Stains?

Posted: Jan 12th, '18, 21:46
by SimonP
Thanks for all the suggestions
I'll try each and report back!

Re: How do I Get Rid of Hull Stains?

Posted: Jan 12th, '18, 22:57
by INMA
If you use the acid products, you need to apply protection after the cleaning.

The acids kill the galvanising on trailers.

Easier just to buy a polisher and use fibreglass restorer. I use 3M products but they all should be good.

Re: How do I Get Rid of Hull Stains?

Posted: Jan 13th, '18, 08:28
by Tinggu
After up to 2 weeks in the Lakes water I've found that one of those cheap green scratchy things does the job very quickly with the aid of a hose. I generally use an old worn out one as I suspect a new sharp one might damage the paint. I was wary at first but now 3 years later I'm happy it's not doing any harm to the 2 pack hull or the antifoul bottom. I wish I knew what antifoul was used - it does a great job and I'd use it again in a flash.

Re: How do I Get Rid of Hull Stains?

Posted: Jan 15th, '18, 15:58
by MargGannet
I found exit mould - and the equivalent bunnies version - dissolved the stains on my deck pretty rapidly. Haven't tried it on the waterline yet - but will when I bring the boat home!

Re: How do I Get Rid of Hull Stains?

Posted: Feb 9th, '18, 18:12
by huwp
The orange kitchen stain removers tend to get it off pretty easily like someone mentioned before re the lemons.