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Oxalic Acid Crystals

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(£12.59 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,

  • Remove Tannin Stains
  • Rust Stain removal
  • Water mark removal
  • 99% + purity grade
  • Available in 1Kg, 5Kg, 10Kg & 25Kg
Covid-19 Update ~ We're Still Shipping Orders!

Due to the Covid-19 outbreak, we are currently not able to allow customers into our shop here in Bidford-upon-Avon, however we are still operating and shipping goods out using Parcelforce and Royal Mail.

However, due to courier companies struggling with the increased workload, we have taken the decision to temporarily disable any next day services and have a current delivery aim of 3-5 working days for all orders.

This is to ensure that all of our customers are able to receive their goods in the time-frame we have promised.

If you wish to collect an order from our store, we can still offer a safe collection service from outside the building.

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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.

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

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

Excellent product, works very well on removing stains and bleaching oak back to its original look .
Well packaged and delivered prompt.
Removed all stains perfectly from our new green oak fixed garden bench, which had many unsightly black stains.
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