Why are spots and stains reappearing after I’ve cleaned them?
It’s happened to nearly every cleaner at some point. You get a call from someone you thought was a satisfied customer. The carpets were spotless when you left, but now they report that stains you removed yesterday have magically reappeared. So what happened?
This “phantom stain” phenomenon is caused by a process known as “wicking”, which is the upward flow of water (and anything dissolved in that water) to the surface of carpet fibers as they dry. Where this becomes a problem is when more than just clean water is left to dry in carpets or upholstery.
Deep stains (such as pet urine or a spilled cup of coffee) are like an iceberg; often the visible stain is much smaller than what’s actually in the carpet backing. When cleaning carpets using an extractor, the cleaning solution used can re-wet those deep stains. Wicking then pulls up the residual staining agent from the bottom of the carpet fiber, causing it to reappear!
It may occur as an overall condition, as splotches, or as a few spots.
So how do you prevent it?
Your best bet to avoid returning to fix a phantom stain is to identify potential wicking issues before they occur, and treat them accordingly. Wicking usually only happens when a liquid spill is allowed to deeply penetrate the carpet and its backing. If possible, ask the owner if they know the cause/source of spots when you encounter them.
Since the source of wicking spots tends to be a liquid, these spots are more likely to have a moisture reading prior to cleaning, meaning they can often be identified by a moisture meter as well. Once you anticipate a potential problem spot, consider the following measures to prevent stains from wicking up.
1. Avoid Over Wetting
Once a spill has soaked through the carpet and into the padding and sub-floor, it is often impossible to fully remove all of the staining agent. When this is the case, the goal is to remove the visible stain from the carpet, without allowing the sub-surface portion of the stain to get wet enough to wick. This means avoid flushing the area, as well as follow with dry strokes to ensure as little extra moisture is left in the carpet as possible
2. Use High Quality Tools
Modern, quality equipment can help you avoid wicking issues as well. Using wands with higher recovery abilities, such as the Bentley™ Wand or Bentley™ Pro Speed Wand with positively ventilated glides, leave carpets drier and less susceptible to wicking.
Upholstery tools with internal jets, like the Mytee Dry™, prevent over wetting. Couches, seats and other upholstery are just as susceptible to stains wicking back as carpets are. Take the same cautions when dealing with upholstered items as you would carpets, and leave them dry as possible.
Using underpowered machines or operating outside of the equipment’s effective range will also cause longer dry times, and with it, a greater risk of stains wicking. Use an extractor with high performance vacuums to ensure you leave the carpets dry as possible. For example, LX™ units from Mytee deliver 180” of water lift and 250 CFM, making them effective at recovering max amounts of water even beyond 150’ of hose.
3. Take Extra Steps to Dry Carpet Quickly
When you suspect a potential wicking issue, take extra steps to dry the area as quickly as you can. Use fans or airmovers if you have them. Turn on AC when you can. Any measure you can think of that will aid in lowering the humidity of the general area. The quicker an area dries, the less time you allow for stains to wick back up to the surface.
4. Try Low Moisture Cleaning Methods
If you have the tools available, VLM/encap cleaning can take care of trouble areas and stains, and thanks to their inherent low moisture nature, pose a much lower risk of causing wicking. With loads of other applications and advantages, low moisture cleaning is certainly a method worth considering getting into, whether for spot applications or full cleaning with an orbital machine or CRB.
Click here to watch our video on how to use an ECO orbital!
