What poultice works for red dye on Yorkshire stone?

Q. Please advise what kind of poultice should I use for red shirt dye in Yorkshire stone flag stone.

A. Yorkshire stone is a soft, thirsty sandstone that grabs color quickly. The good news is that most clothing dyes are organic, which means they can often be lifted with a poultice. A poultice draws the stain out of the stone over time. For detailed, step-by-step instructions on how to mix and apply a poultice correctly, check out our free Stain Management App. 

The poultice most stone pros would reach for in this situation is a hydrogen-peroxide paste. Not the weak 3% brown-bottle stuff, but the stronger 30/40 volume peroxide sold at beauty supply stores. The peroxide breaks down the dye, and the powder literally pulls the dissolved pigment up out of the stone as it dries. Follow the manufacturer’s safety precautions.

Yorkshire stone should respond well to this treatment. You may need to repeat the process two or three times. If the stain is stubborn, you may add a few drops of household ammonia to your poultice.

Keep in mind that Yorkshire stone does not like acids of any kind. Acids can etch or roughen the surface, making the stain even harder to deal with. You'll also want to avoid scrubbing pads or harsh cleaners.

Let the chemistry do the work. If the patch of dye has been sitting for a long time and has sunk deep into the stone, you might eventually reach a point where poultices stop pulling out more color. At that stage, a stone restoration professional can lightly hone the surface to even everything out. To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO.

Chances are the peroxide poultice will save the day before it comes to that.

ABOUT THE AUTHOR Fred Hueston is the Chief Technical Director at SurfaceCarePROS.com and Director at StoneForensics.com. He is also the author of Stone and Tile Restoration: The Manual, a comprehensive online manual for stone and tile restoration contractors. [Learn more about Fred.]