Stains in gel coat above the Waterline

[Neil 35]

Any experts out there on how best to tackle this kind of staining? Any help, suggestions much appreciated...

 

 

[Black Panther 1,584]

Toilet bowl cleaner then a good wax to seal it up.

[John B 106]

The expensive way is T jett teak brightener, but there are other spray on products in smaller packs and cheaper.Just ask at the chandler.

I have the brightener , so I use that once a year. But you do need to wash it off and then wax it.

[funlovincriminal 162]

 

Have you tried this Neil? - Seems made for the job 

[SloopJohnB 323]

and something my wife does not have........elbow grease.

[Kevin McCready 83]

I raised my antifoul ~100 mm.

[all fired up 6]

In the past I have used a dilute Oxalic Acid, and wiped it on with a sponge mop.

For a more expensive solution I have also used GRUNT - Emergel, rust, stain and oxidation remover.

 

a.f.u

[Island Time 1,235]

AFU has the answer. That stain will dissolve with no elbow grease at all. Buy some Oxalic acid powder from Bunnings for under $20. It will last you for years. this is what the active ingredient in Grunt etc is.

Use 2 teaspoons of it in a 1/2 litre of water, and wet a cloth. Use gloves. Wipe the damp cloth over the stain, and give it 5 mins. You really will be amazed! You can hose the area when finished.

It is a good idea to polish the area with a quality canuubra (sp?) car wax, or the stain will come back sooner.

[John B 106]

I think that's what is in the teak brightener too. 30 second, spray and walk away, maybe even 10 second , no elbow grease , will stain the antifoul at waterline.

[wheels 543]

Oxalic Acid is what is used in Timber cleaner/brightners, Wooden deck cleaners and etc etc.

[ScarecrowR31 8]

Rhubarb!

[harrytom 642]

I used burnsco waterline stain remover lasted 12 months

[Neil 35]

Thank you all.

 

 Oxalic Acid it'll be...

[Tim C 23]

I've used many of the products above, but have had the stain return relatively quickly, despite trying various waxes. Note this is on two part polyurethane paint, not gel coat. 

Six months ago clear coated my boat with Nyalic by roller, and to their spec. The brown stain stayed away! I'm most impressed by the product. Not cheap, but effective.

(The usual disclaimer here of having nothing to do with the company mentioned, just recommending a good product)

[Island Time 1,235]

Hi Tim, yeah, I've tried it, but in my case I found that it broke down in UV after about 2 year and looked crap... Hope yours lasts better!

[1paulg 17]

Nyalic when it breaks down is a nightmare to deal with as well.

[Tim C 23]

Well I was getting down to two weeks before the brown stain returned after the Oxalic acid treatment, and following with a wax. 

If you look at the bows of many boats in a bay there are many with brown stains. Somedays I'm not sure marine paint has improved over time...

[wheels 543]

I don't think it's the Paint that's the problem Tim. There's something in the water
Actually, it would be interesting to get an analysis of the surface and see what it really is. It could be simply a slime/algae, or it could be something washed off our roads now we have different emission controls on vehicles, or it could be a mineral or similar from Soil washed off the land from all the new work around Auckland. Perhaps even a "tea stain" from tannin's from vegetation.

[Island Time 1,235]

It's worse on old paint/gel coat though. I reckon related to surface permeability?

[ScottiE 174]

Surely a decent waxing of the hull every year is the best answer.

I recall Mr Marine would do this religiously every year with Double Diamond and she always looked mint.