Oxalic acid.. Dilution by weight?

[oldestgit]

Oxalic acid:
Can any kind soul please advise how much by weight (grams) I should add to say a gallon of water to clean off the lichen and green crud from teak and stains from white gel coat.

Thanks... Peter

 

[VicS]

Links from THIS PAGE to Instructions and Safety Data.

Make it saturated if you wish.

Add wallpaper paste to thicken it for cleaning vertical surfaces.

It is good for cleaning off rust stains and the brown stain around the waterline and
for removing stains and lightening wood but I was not aware that it had any particular merits for cleaning algae and lichen from teak decks. A deck cleaner containing an algaecide might be better.

 

[FullCircle]

Yep, agree with Vic, although we use 50g per litre, and 1.5 tablespoons of wallpaper paste.. Mix to your strength requirement really.

 

[graham]

Will that be a strong enough mix to remove brown waterline staining? I have this job to do soon so have followed the thread with interest.

 

[VicS]

[ QUOTE ]
Will that be a strong enough mix to remove brown waterline staining

[/ QUOTE ] Make it near saturated. Put some hot water in a jar and add the oxalic acid crystals until no more dissolve. Then add just a little more water.

(Never been able to find a reliable figure for the solubility, probably because some sources quote it as the weight of the dihydrate per 100cc while others give it as pure anhydrous oxalic acid)

When cool add some wallpaper paste to thicken.

Remember to label any that is unused and to keep out of sight and raech of children. Read the safety data.

 

[oldestgit]

Thanks Chaps.

Yes Vic, I think you are correct I guess it’s not the main man for lichen & algae.
I also thought it was a less concentrated mix, (fading memory).

Thanks again especially for the link……. Peter

 

[jmh2929]

Have a look at this example It was a quick wipe the evening before just for fun, the mix was quite strong

 

[graham]

Thanks for the advice people. Im looking forward to doing it now and a few small gelcoat repairs and a polish .Ill probably row past thinking She is a different boat. /forums/images/graemlins/grin.gif

 

[patturner]

WHERE CAN I BUY OXALIC ACID??

 

[jmh2929]

My local chemist gets mine. About £5 or so for half kilo crystals.

 

[VicS]

[ QUOTE ]
WHERE CAN I BUY OXALIC ACID

[/ QUOTE ] If your local pharmacist won't get it for you you can order it from AG Woodcare at £8.94 per kilo

 

[FullCircle]

As other suppliers are avaialble, I recommend one to you for balnce of thread.


Here

http://www.wessexchemicalfactors.co.uk/marine_exteriorcleaning.htm


All of their products are mustard, particularly the Teak Cleaners!

 

[VicS]

[ QUOTE ]
Teak Cleaners

[/ QUOTE ] I have been looking for product data and safety data sheets for their teak cleaners. Do you know where to find them. If not, next time you deal with them ask them what about this info!

 

[StephenW]

2 ounces to a pint works well . Can be potentially nasty stuff so I'd be careful going too concentrated

 

[VicS]

[ QUOTE ]
Can be potentially nasty stuff so I'd be careful going too concentrated


[/ QUOTE ] I have already indicated where the safety data sheet can be found.

It is classed as "harmful". Gloves and goggles or safety spectacles would be appropriate personal protection.

It is in fact somewhat corrosive but not in the same way as the strong mineral acids such as sulphuric or hydrochloric. It is also poisonous but not sufficiently so to be classified as "toxic".

You suggest a solution of 2ozs per pint. Assuming you are referring to 2 ozs of the dihydrate that works out at about 70% of saturation anyway . Saturated if you are referring to the anhydrous material.

 

[Wunja]

I too have brown water lines stains (on the boat), so I'm interested in this thread. However, does anyone know what the environmental issues might be with the used stuff that's washed off?

 

[graham]

Hello Vince I did wonder about the environmental effect as I am doing mine afloat.When you consider it only takes about a cupfull per side it must be so diluted as you wash it away that its hard to imagine it causing any harm.

Did one side tonight but ran out of time to complete.A narrow strip about 2 inches wide at the waterline needs redoing if it doesnt clean up I will use some boot top paint next time ashore or just raise the waterline a couple of inches.

before

after

I wasted a lot of time using kitchen cleaners etc before using the oxalic acid.Its easy and it works.

 

[VicS]

[ QUOTE ]
what the environmental issues might be

[/ QUOTE ] It is not classed as dangerous to the environment