Oxalic Acid 350 g Forever

Oxalic acid is suitable for most wood species, whether soft or hard, native or exotic. It is particularly effective on wood greyed by weathering and wood stained by moisture or tannin. Always test on a discreet area, as some very light woods may slightly change colour. On old varnished or waxed wood, preliminary stripping is necessary for the product to work effectively.

The concentration depends on the intensity of treatment desired. For light greying removal, allow approximately 50 to 100 grams per litre of warm water. To eliminate stubborn rust or tannin stains, you can increase to 150 grams per litre. The 350 gram pack allows you to prepare between 2 and 7 litres of solution depending on your needs. Always start with a less concentrated solution and adjust if necessary.

Contact time typically varies between 10 and 30 minutes depending on surface condition and stain intensity. Regularly monitor treatment progress and never allow the product to dry on the surface. For light stains, a few minutes suffice. For deep greying removal or embedded rust elimination, you can extend to 30 minutes while keeping the surface moist.

When used correctly and in recommended concentrations, oxalic acid does not damage wood. It acts only on the surface to remove stains and greying without altering fibre structure. Thorough rinsing after treatment is essential to stop the product's action. Avoid repeated applications too close together on the same area and respect drying times before any finishing.

Yes, oxalic acid is effective for rust removal on tile, polyester surfaces (boat hulls) and for de-oxidation of non-ferrous metals such as copper and brass. It also removes waterline stains and algae on composite materials. Adapt concentration and contact time to the type of surface being treated.