Hey,
I just bought a boat that has been a bit unused for the last couple of years. Till I get around painting the bottom, what is acceptable and safe to use to clean the topside, while still in the water? I'm in NSW, but cannot find any regulations on what the law stipulates
Thanks.
Last week I sprayed 2 patches: one with white vinegar (I use it to clean up from epoxy resin), and the other patch with an orange kitchen spray thing. Neither did much effect. The only thing that worked was fresh water over these areas and hard scrubbing. I don't have access to 240v electricity and a pressure washer at the dock , but that would've been far easier.
I used one of these pads: www.bunnings.com.au/sabco-professional-red-utility-pad_p0065289 as well as a normal bristle brush for kitchens. This red pad was good for lichen and deep grime, but hard work.
As far as the regs go you probably can't clean it in the water, but on the other hand you have to keep it presentable, I've had Bso pass by while I've been cleaning topsides and just not even see me. What sort of boat ?
It's a Cavalier 32. Anyone use Oxalic acid? Dulon sells it as "hull & waterline cleaner". Says it is biodegradable and safe for the marine environment. But I do get that it may be frowned upon . I do understand if you just rinse it off and let it run off into the water, that may not be good. But to use it sparingly and wipe off with rags afterwards, I don't foresee much harm in that. I was in the Navy, and we used far worse stuff to clean things out at sea
Oxalic acid works really well on topsides. It is toxic so don't have it too strong. It will go through your skin so gloves are an absolute must.
I would not spray it. A dust pan brush is fairly ideal to apply it with from a bucket. Apply to the topsides. Wait for the stain to fade away, then rinse with water, salt or fresh.
If you are doing it anchor, salt water is the obvious but if alongside fresh would be the best.
In Cairns some guys, moored on the piles across the other side of the inlet, would put oxalic in crystal form in a hessian bag and hang it from the bow on an outgoing tide. Got rid of their barnacles alright.
Probably not an environmentally responsible thing to do but hey, it is not the average yachtie that is spoiling the environment. The military and commercial shipping use the most toxic antifouling imagineable. They only do a bottom clean every five or more years.
Just put it on and rinse it off and keep your concience in the locker. 
Oxalic acid is sold as diggers rust & stain remover from the big green shed. For more stubborn rust staining phosphoric acid. Food grade can be got from cleaning suppliers, it's cheaper than buying it as rust converter. & congrats
Select to expand quotecisco said..
The military and commercial shipping use the most toxic antifouling imagineable. They only do a bottom clean every five or more years.
Arguably the big guys ( both merchant and military) are becoming the most environmentally compliant with the ongoing industry shift to biocide free silicone antifoul. It's being been done for economics, lower drag over the period of use, bow thruster tunnels etc remain clean. It's good stuff.
Dilution is the solution to pollution. So as long as you do it sparingly the acid won't be harmful.
Metal gleam. It's a phosphoric acid mixture mainly. Mix 1 to 5 with water, warm water works best. Use a soft broom and use it on all fibreglass or paint surfaces. Also use the same mixture ratio for cleaning heat exchangers and raw water cooling systems as you would if you used "Barnacle Buster". Makes your stainless stuff sparkle as well. I used to buy it in 20 litre containers when I was a fisherman. Harmless on the skin unless you have a scratch. Keep away from the eyes.
nowchem.com.au/shop/heavy-duty/metal-gleam/
