Harry asked: I spilled methylated spirits on black (oxide colored) concrete. This has caused white marks that will not come off when scrubbed. How can I remove them?
White spots left on concrete by methylated spirits (also known as denatured alcohol) are probably actually bleached or faded areas left by the contact. This means they cannot be scrubbed off or simply removed. You can restain the concrete, or you can try this quick fix to add color back to a small area.
You Will Need:
- Black acrylic universal tint concentrate or paint
- Concrete sealer
- Cup, bowl, or small bucket
- Brush or clean rag
Steps to Remove the Stain:
- Make sure the tint and concrete sealer are compatible products. Follow all label instructions and precautions, including those for skin and eye protection, before you begin.
- Mix the tint or paint with the sealer in a cup, bowl or small bucket (depending on how much stain you need). Blend until you have a color that closely matches the area of concrete you’re working with.
- Once you have a match, brush or rub the stain onto the faded area.
- Allow to dry.
Additional Tips and Advice
- Depending on the type of stain you have, it may not be possible to exactly match the original concrete but you should definitely see an improvement in the overall appearance.
- If the affected area is a large one, it may be easier to simply reapply stain, then seal.