Oxallic acid - confession ( How stupid I was!)

[branko]

I have read all posts regarding Oxalic acid and accept all info about safety measures have to be taken and I wear gloves , old shoes,….. put 100g Oxalic acid in bucket, enter in boat where I have hot water and fill it with water. At that moment acid cloud fill the inner space and hit my respiratory organ. After that I need few hours for recuperation. One of my friends -chemist teach me one of the elementary chemical rules - NO WIA (no water in acid!).
At the end my teak deck looks very good!

 

[davidbains]

I soaked my rust marked staysail in oxalic acid in a swing bin on the ground.
Pulled sail out after a few hours and found several of the bronze cringles and
hanks were rapidly dissolving!! Sail was clean and white again though.

 

[Anchorite]

Nmemonic

For safety's sake, do as you oughter
ADD THE ACID TO THE WATER.

 

[LeonF]

Thanks for the warning....I am about to try and buy some.. where did you get yours ???

 

[BrendanS]

quite a few ideas on where to purchase in this recent thread

Click here

 

[Talbot]

Another source for oxalic acid is http://www.agwoodcare.co.uk/index.html and search for oxalic.

They also have a "How To" -

Dark spots and discoloration of the wood surface are usually caused by water spots and can be removed with oxalic acid. Oxalic acid is also used to freshen wood color if it has become grayed.

Instructions

Pour 2-4 tablespoons of oxalic acid crystals in a heat resistant glass jar and add one pint hot water. (The strength will vary according to your needs, 2 tablespoons for milder solutions and 4 tablespoons for stronger.)
Apply solution to entire surface evenly with a cloth, sponge, or brush. Do not apply just to the spot or discolored area. If you treat only the stained area, you have uneven bleaching with light spots rather than dark spots.
Let the solution remain on the wood 10-20 minutes. If the stain remains, apply more solution to the stained area only. Continue to apply until desired color is obtained.
To neutralize acid (stop bleaching action), wash the surface with a weak solution of 1 tablespoon clear (not sudsy) ammonia to 1 quart of water. If clear ammonia is not available, wash with a solution of 2 tablespoons borax dissolved in 1 pint of water. Wipe up excess moisture with absorbent cloths. Rinse with clear water and wipe with dry cloths. Remember that water will raise the grain of the wood. Let dry 24 hours before sanding. Sand down the raised grain or staining will be darker in the raised area.

 

[chewi]

Instructions

Pour 2-4 tablespoons of oxalic acid crystals in a heat resistant glass jar and add one pint hot water..

I almost sent these instructions to a mate as they are...
but they actually advise to add the water to the acid.!

 

[RichardS]

I almost sent these instructions to a mate as they are...
but they actually advise to add the water to the acid.!

It's a very old thread ..... but with oxalic acid you can make it up any way you like.

I think some of the posts above are referring to the dilution of strong acids like sulphuric.

Richard

 

[viago]

i tried oxalic acid on my grey rubbing strakes with little success. in the end i put some wallpaper paste in the mix so it stayed in place a bit better. worked ok but a belt sander would have been much quicker than all that faffing.

i dont like the idea of working with acid anyway but everyone seemed to swear by it. i wont be using it again.

 

[Spirit (of Glenans)]

i tried oxalic acid on my grey rubbing strakes with little success. in the end i put some wallpaper paste in the mix so it stayed in place a bit better. worked ok but a belt sander would have been much quicker than all that faffing.

i dont like the idea of working with acid anyway but everyone seemed to swear by it. i wont be using it again.

A sander will produce a quick and effective result, but if you repeat the process a number of times you will find that you end up with considerably thinner timber components

 

[ianabc]

Kidney stone / risk too

 

[longjohnsilver]

Thanks for the warning....I am about to try and buy some.. where did you get yours ???

Cheap as chips on eBay

 

[Capt. Clueless]

I've got around 10ltrs of the stuff (presumably diluted) that I found in one of the lockers of my boat. He'd even drawn a pic of a skull & crossbones on the plastc contaners. I'm wondering if the previous owner drank it or something.

 

[VicS]

I've got around 10ltrs of the stuff (presumably diluted) that I found in one of the lockers of my boat. He'd even drawn a pic of a skull & crossbones on the plastc contaners. I'm wondering if the previous owner drank it or something.

It normally comes as a white crystalline solid or powder. Odd that anyone would make up and store that volume of solution. It would be more convenient to store the solid and make up small quantities of solution as required.