New item Ping
Add this item to Cart for a combined free shipping deal
Click to enlarge photo

Listing Detail Tabs

Oxalic Acid 1kg (99.6 purity) - CHEAPEST ON Trademe

Oxalic Acid Wood Bleach
Very effective and useful for eliminating black rust stains on wood, e.g. where firearms have gotten wet and not been disassembled, the metal rusted and stained the wood). Mix as directed, apply warm, rinse and neutralize as directed, very simple, works wonders.


Have you ever removed the finish from a piece of furniture and found black stains or black rings from metal pots? Have you ever removed the finish from a floor and found black or deep brown pet urine stains in the wood, which no amount of sanding will take out? These are all iron stains caused by the chemical reaction of tannic acid in the wood mixing with the trace metals in urine and water.

Oxalic acid is an all natural, organic compound. It’s found in vegetables like sorrel, spinach and rhubarb. There’s so much of it in rhubarb leaves that we don’t eat them, they’re poisonous! There are many processes to extract it from vegetation, but modern methods manufacture it through the oxidation of carbohydrates or glucose using nitric acid or vanadium pentoxide. It is a relatively strong acid for it’s acid group. It is important to use protective gear when handling oxalic acid.

The main use of oxalic acid can remove is as a bleach, particularly with wood and to remove iron stains all while not bleaching the wood. For small spots, it is suggested that users mix about two tablespoons of it in a quart of hot tap water and allow it to dissolve. For larger spots, or entire sections of a floor, there are directions on the next tab.

When dissolved, use an artist brush and paint it in the mixture on the stained areas only. Allow to dry. The stain will lighten. If it does not disappear, then do another coat. You may need to coat it three or four times, allowing time to dry between coats. Once the stain is gone you can sometimes get a slight halo effect around the area where the stain was bleached. Please click here to ask a question
Your question and answer privileges have been disabled.
You must log in to view questions and answers on this listing. We recommend reading questions before you make any purchases.
You must log in to ask or answer questions posted. We recommend reading questions before you make any purchases. Available only to approved bidders. You must be an authenticated member to ask questions Find out more about becoming authenticated. Your account is in debt Your current account balance is You must credit your account to use this feature.
Firearms licence #
Firearms licence holder name
First name is required
Last name is required
Your current account balance is Please note you will lose your question and answer privileges if your account is in debt for more than 2 weeks. Credit your account.
I confirm that I am over 18 years old.
To prevent your personal details being misused please do not put emails or phone numbers in questions. Failure to comply may result in the suspension of your account. The seller cannot add a Buy Now price once bidding has started.

Shipping options

Buy more than one of this item and only pay for shipping once.
  • Seller allows pick-ups
  • Seller location: Manukau City, Auckland, NZ

Payment options

  • Other options
    Cash, NZ bank deposit

Ping and Afterpay include:

Buyer Protection Learn More