Oxalic Acid Dihydrate - Rust remover / Wood bleach / Hull, Deck Cleaner

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1Kg £13.33 £15.99
2Kg £16.66 £19.99
5Kg £22.91 £27.49
10kg £34.99 £41.99
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Ethanedioic acid

Technical grade 

For Oxalic Acid 6% Solution Click Here

What is oxalic acid: Oxalic acid is an organic compound with the formula H2C2O4 also known as Ethanedioic acid. It is a colourless crystalline solid that dissolves in water to give colorless acidic solutions. It is classified as a dicarboxylic acid. Oxalic acid is a relatively strong organic acid with many commercial uses especially in the carpentry and joinery trades in the UK. Oxalic Acid can also be used to freshen wood colour if it has become grayed due to external exposure. In the refinishing of wooden furniture, oxalic acid can be used after stripping to lighten darker stained areas. It can also be used as a rust remover and a stain remover in many other applications. 

Where to use Oxalic Acid

  • Wood bleach - To bleach old and stained wood removing tannin stains and water stains
  • Rust removal- in removing rust on boats, in automotive shops and in restoring antiques
  • in rust stain removal without harming Gel coat, fibre glass, steel and other metal surfaces
  • for pre-treating stainless steel
  • As a grinding agent in preparing & polishing stones & marble
  • in restoring furniture
  • For removing hard water stains from tiles and plumbing fixtures.
  • as a precipitator in rare earth mineral processing 
  • It is an important reagent in Lanthanide chemistry.
  • Oxalic acid is used as a mordant in dyeing processes.
  • It can be used as a reducing agent in photography.

How to use Oxalic Acid

Prepare a solution by dissolving 60g of oxalic acid in 1 litre of water, apply to stain or rust and allow to work for 20-30 minutes. Always rinse thoroughly with clean water. For wood bleaching it is recommended to neutralize after treatment with a borax solution (3 tablespoons of borax dissolved in 1 litre of water).

When using on wood the wood must be free of all coatings, waxes & oils. It is necessary to use appropriate strippers and cleaners to remove coatings. 

PLEASE NOTE: This product is not for human or animal consumption.

Properties of Oxalic Acid Dihydrate:

  • CAS No: 6153-56-6
  • EINECS No: 205-634-3
  • Formula: HOOCCOOH.2H2O
  • MOL Wt: 126.07
  • Toxicity: Oral rat LD50: 7500 mg/kg
  • Physical state: white crystals
  • Melting Point: 101 - 102 C
  • Boiling Point: 149 - 160 C (sublimes)
  • Specific gravity: 1.6-1.7
  • Solubility: 1g/7ml
  • Vapour density: 4.4
  • Flash point: 163 C


Health & Safety:

EU Classification Symbol: Xn

R: 21/22
S: (2-)24/25

Harmful if swallowed.
Causes severe skin burns and eye damage.
May cause respiratory irritation.

UN Hazard Class: 8
UN Pack Group: III


Click here for MSDS