Oxalic Acid Crystals (With FREE Safety Kit)

In stock
(£11.75 inc VAT)

Oxalic Acid is used to remove dark stains, water marks & to refresh the woods colour especially oak, can also be used to remove ink stains, it is also an effective rust stain remover from concrete & metal, supplied in crystal form to be mixed with Water or Methylated Spirits to make an effective wood bleacher, included with every order is a FREE Safety kit : 1 x Pair Goggles, 1 x Mask, 1 x Pair of Disposable Gloves. (1 x kit per order only SUBJECT TO STOCK!)

99% + purity grade

Available in 1Kg, 5Kg, 10Kg & 25Kg



Dark Spots, tannin stains & discolouration of the wood surface are usually caused by moisture and is exacerbated when the moisture is contaminated with metal such as iron and steel (especially on Oak & Idigbo) and can be removed with oxalic acid.

Oxalic Acid can also be used to freshen wood colour if it has become lightly grayed due to external exposure to sun light. In the refinishing of wood furniture, oxalic acid can be used after stripping to lighten and soften darker stained areas before refinishing. It can also be used as a rust remover and a stain remover in many other applications.

Just hearing the word "acid" sounds ominous but oxalic acid is easy and safe to use in the home. In fact it is found in many vegetables including spinach, and rhubarb and is also used in shampoo and washing powders.

Oxalic Acid is supplied in crystal form and looks just like sugar.

How to use:- Simple mix with water as you would mix sugar in tea, in a clean container add the crystals to the water stirring until their is a little undisolved sediment floating around the bottom, you then have a ready to use saturated solution, (approx 60g to a pint of water) Adding more Oxalic acid crystals will NOT make the solution any stronger.

You could use Methylated Spirits instead of water. Using Methylated spirits allows for quicker drying enabling a protective coating to be applied to the timber sooner. Do not breath the fumes

Apply solution direct on to the timber with a brush, any surface coating such as woodstain, paint, wood oils etc will prevent the oxalic acid solution from working so all protective coating will have to be removed first.
The bleaching process will continue for 1 - 2 hours, but could remove the stains within 20-30 minutes. It may require multiple applications to fully remove the staining but once removed the timber will need to be thoroughly cleaned with clean water or meths and then allowed to dry.

One kilo of oxalic acid will make approx 8 - 9 litres of ready to use solution and with a coverage of 12sq meters per litre (depending on porosity of the timber)

Our oxalic acid is a high commercial 99% + purity grade, not all oxalic acid for sale are the same.
A pre mixed Oxalic acid Wood Bleacher is also available as a ready to use liquid in 150ml, 250ml, 1L, 2.5L & 5L

Warning: Oxalic Acid is still an acid and should be treated with respect. In its purified form, oxalic acid is a highly corrosive and toxic substance. Latex gloves should be worn at all times when using it and it should always be mixed and used in a well-ventilated area.

Always protect your skin and wear a dust mask when mixing.

Pack size: 1Kg, 5kg, 10Kg and 25kg sacks.

FREE Safety kit included with all orders: 1 x pair Goggles, 1 x Mask, 1 x Pair of Latex Gloves. (1 x kit per order only & SUBJECT TO STOCK!)

Health & Safety Sheet (Oxalic_Acid_COSHH_Data_Sheet_PDF.pdf, 135 Kb) [Download]

Data Sheet (more_info_oxalic.html, 3 Kb) [Download]

Oxalic Acid is brilliant for removing stains from oak flouring. Superb service from AG Woodcare

Seems to work well and cleared up most of the tanin stains with some light scrubbing.

Took a chance that it would lighten some wood that had been treated with wood stain. Pleased with result although hasn't stripped it entirely-but wasn't expecting it to anyway.

I am using the crystals to control varroa mites in my beehives. I heat it and the vapours circulate inside the hives killing the mites. the crystals are working very effectively. thanks.

great product , easy to use , i have used this product for over 45 years i think it beats similar products , and it comes with safety kit which is a bonus

Used it to remove some very stubborn rust stains from a set of dinghy sails. Worked well, removing most of the rust stains, and made the white sails much cleaner.

I used this on a beech chair which had black staining from water damage. It was easy to use and removed most of the staining so I would recommend it.

AG Woodcare Products Ltd has a good web site and the item was deliivered promptly and safely. The acid was used to remove rust stain from stone fireplace. Took several attempts but satisfied with final result. The face mask supplied didn't prevent the occasional fume from reaching me and cause a little coughing but overall seems a safe product to use. Pity a smaller quantity isn't available.

Excellent product, works very well on removing stains and bleaching oak back to its original look .

Well packaged and delivered prompt.
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