Oxalic Acid Dihydrate Crystals 99.6% (100g)

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Oxalic Acid Dihydrate Crystals 99.6% (100g)

This high-purity oxalic acid effectively removes stubborn stains from bare wood, including water marks, rust, mildew, and ink. Used by woodworkers and restorers, it revives timber’s natural appearance without harsh abrasives.

Condition Perfect Slightly Dented Tin (by Amazon)

£9.95 GBP

~~£9.95 GBP~~ £9.95 GBP

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KEY APPLICATIONS

Black & Dark Stain Removal: Effectively removes stubborn stains on kitchen worktops, external oak structures, wooden doors and floors
Tannin Stain Removal: Restores wood's natural appearance by neutralising tannin discolouration
Rust Stain Removal: Eliminates rust stains from both wood and concrete surfaces
Water Mark Removal: Effectively reduces or eliminates water marks and water damage
Wood Restoration: Brings back the natural beauty and colour of aged or stained wood

PREPARATION GUIDE

For best results, use our easy preparation guide:

Solution	5%	10%
50ml	2g	5g
100ml	5g	10g
250ml	12g	25g
500ml	25g	50g
1.0L	50g	100g

HOW TO USE

⚠️

Safety First: Always wear protective clothing including rubber gloves, face mask, and safety glasses. Keep away from children.

Application Method

Apply the hot solution to bare wood with a brush, sponge, or cloth
Let the solution work on the stained area for 10-20 minutes
Rinse the surface thoroughly with clean fresh water
Allow the wood to dry completely before applying any finish

Trade Tip - Using Soda Crystals

A professional technique for neutralising oxalic acid after application:

Mix soda crystals at the same ratio as the oxalic acid (10:1 in very hot water)
Apply the soda solution shortly after the oxalic acid application
You'll see an immediate reaction - this neutralises the acid
This process can be repeated, though effectiveness lessens with each application

Alternative Method

If you are trying to avoid raising the grain of your wood surface you can alternatively use methylated spirits to dissolve the oxalic crystals. The advantage being a quicker drying time for finishing.

FAQs

What is oxalic acid, and what is its purpose in woodworking?

Oxalic acid is a naturally occurring organic compound that is often used in woodworking for its bleaching and cleaning properties. It is particularly effective at removing stains caused by water, rust, tannins and at lessening the marks left by ink pens, coffee and tea. Oxalic acid is often used to help restore wood's natural colour prior to refinishing.

How do I safely use oxalic acid on wood?

When using oxalic acid, it's essential to take safety precautions since it can be harmful if ingested, inhaled, or if it comes in contact with the skin. Use gloves, goggles, and a dust mask when working with oxalic acid. To use it on wood, dissolve the oxalic acid crystals in hot water according to the manufacturer's instructions. Apply the solution to the stained wood using a brush, let it sit for the recommended time (usually 10-20 minutes), then rinse thoroughly with water. Allow the wood to dry completely before refinishing.

Can it damage wood?

When used correctly, oxalic acid is safe to use on wood and should not cause any damage. However, excessive use, incorrect dilution, or prolonged exposure can potentially lead to the wood becoming discoloured, weakened, or damaged. Always follow the manufacturer's instructions for proper dilution and application to minimise the risk of damage.

Will it remove all types of stains from wood?

It is particularly effective at removing stains caused by water and rust. It also can be very effective at removing other stains as mentioned above, but it's not guaranteed to work. You may need to seek professional help with removing stubborn stains and marks.

Can I use it on all types of wood?

It can be used on most types of wood; however, it is most effective on woods with high tannin content, such as oak, teak, walnut, or mahogany. On woods with low tannin content, the bleaching effect might not be as pronounced. It's essential to test the oxalic acid solution on a small, inconspicuous area of the wood before applying it to the entire surface to ensure that the desired effect is achieved and to avoid potential damage.

Can you use oxalic acid on veneer?

Yes, you can use it on veneered and solid wood furniture.

MISCONCEPTIONS

Oxalic acid is a universal stain remover

While oxalic acid is effective at removing certain types of stains, such as those caused by water and rust, it is not a universal stain remover. It may not effectively remove 100% of other types of stains, such as grease, ink, or dye, but in our experience it certainly does greatly lessen them. Some stubborn stains may require specific cleaning methods or more aggressive professional wood bleaches.

Oxalic acid can bleach any wood type evenly

Oxalic acid is more effective at bleaching woods with high tannin content, such as oak, teak, walnut, or mahogany. Its bleaching effect may not be as pronounced on woods with low tannin content. Therefore, it's essential to test the oxalic acid solution on a small, inconspicuous area of the wood before applying it to the entire surface to ensure the desired effect is achieved.

Will it restore colour to sun-faded bare wood

Oxalic acid primarily works on stains caused by water, rust, or tannins and may not be so effective in restoring the colour of wood that has been faded due to sun exposure. However, saying this, again in our experience we have often found it to be very effective at restoring the natural colour of the timber. Sun-faded furniture and wood often requires a combination of actions, such as sanding, treating with oxalic and refinishing.

Can I use it as a wood finish

Oxalic acid is a cleaning and bleaching agent, not a wood finish. It can help remove stains and revive the natural colour of the wood, but it does not provide any protection or enhancement to the wood's appearance. After using oxalic acid, the wood should be rinsed, dried, sanded and refinished with an appropriate wood finish to provide protection and enhance its appearance.

Oxalic acid is harmless

Oxalic acid is a potentially harmful substance if not handled correctly. It can cause skin irritation, eye damage, and respiratory problems if inhaled. It is crucial to take safety precautions when working with oxalic acid, such as wearing gloves, goggles, and a dust mask. Always follow the manufacturer's instructions for proper dilution, application, and disposal.

Is it the best stain remover for wood?

Oxalic acid is considered one of the best stain removers for wood due to its effectiveness in removing specific types of stains, such as those caused by water, rust, and tannins. However, it's not universally effective on all types of stains, particularly grease, ink, or dye. Different stain types may require specific cleaning methods or specialised, professional wood bleaches.

ECO RESPONSIBILITY

Environmental preservation is very important to us and we make every effort to ensure our products have a minimal impact on the environment:

Quality over cost: We are not driven by a corporate cost-reduction ethos. We select our components based on quality and sustainability rather than the cheapest alternatives
100% Plastic-free: All our packaging is recyclable with no plastic components
Sustainable materials: Recycled cardboard and paper from FSC-approved mixed sources
Eco-friendly closures: Paper & cotton based packing tape with water-based gum adhesive (recyclable with cardboard) and biodegradable raffia twine instead of polypropylene tape
Solar powered: Our workshop roof is completely covered in solar panels and generates far more electricity than we consume

ENVIRONMENTAL IMPACT ADVISORY

Although oxalic acid is a naturally occurring compound, it can be harmful to the environment if not used and disposed of correctly. Large quantities of oxalic acid can be toxic to aquatic life and can harm vegetation if it enters waterways or soil. It is crucial to follow the manufacturer's instructions for proper dilution, application, and disposal to minimise environmental impact.

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A pleasure to deal with...

Pleasant friendly service with an old fashion feel. Loved the sunflower seeds freebie

The Acid Test.

The oxalic acid cyrstals I purchased were as described and arrived in good order and within the scheduled time frame. Perfect; thank you.

Great service

Delivered on time and well wrapped. Also with a complimentary packet of sunflowers which is much appreciated. I haven't used the product yet. However it looks fine and is in sturdy tubs very easy to open but more importantly, has a nice tight lid to keep the chemicals contained.

Amazing stuff!! I found this on your video and decided to give it a try. The results were impressive. Will definitely use again.

Side table marked by sweet tin……….,!

My side table was marked by a tin ……..an unsightly circle mark in black ……. Used this product an was amazed and delighted with the results …….would very much recommend this product. ……many thanks

Almost

The solution removed 95% of a water stain but unfortunately I can still see it after refinishing a table top. Would recommend this for less stubborn stains. Good value and quick delivery.

A work in progress

excellent help, advice and service, will drop some pictures through and comment on the materials on completion of project, currently it is still a work in progress.

Worked a treat!

Brilliant stuff

Excellent product & service

Excellent customer service... product delivered quickly to Northern Ireland and arrived very carefully packaged.

Used to remove deep rust stains in cedar panelling caused by its fixing nails. This product worked extremely well leaving wood surfaces significantly improved. Once sanded & Danish oiled, staining almost unnoticeable and revitalised expensive panelling which otherwise would have had to have been replaced, so very happy with the outcome.

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Oxalic Acid Dihydrate Crystals 99.6% (100g)