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Ask the Expert: Wicking Spots

ask-the-expert-wicking-spotsWicking spots are those pesky spots that reappear after drying. They are one part mystery; one part nuisance. In this Ask the Expert blog, we tackle the why wicking spots are different and what you can do to get rid of them.

Wicking spots are different

Wicking spots are not like regular spots. The spot has actually collected at the tops of the fibers. Other spots typically travel the entire length of the yarn. Wicking spots are also different because liquids have penetrated into the carpet backing or even to the substrate.  A wicking spot is more likely to have moisture readings prior to cleaning. So if you test correctly, you can find them before you start cleaning. Wicking is more likely to occur on hydrophobic fibers such as polypropylene/olefin, triexta and polyester. It can, however, still occur on nylon.

Solving the wicking mystery

If it reappears after drying, can a spotter fix it? Browning treatments and oxidizers can help. A post-application of an  encapsulant, which could be more successful than the browning treatments and oxidizers. After applying an encapsulant, reclean with an absorption method. This has been proven to best course of action.

You can also try pressing a dry terry towel on the affected area to remove additional moisture. Quicker drying with vertical fans also helps. If the fiber is hydrophobic and an over application of moisture has occurred, encapsulants will not work.

When this over wetting occurs, you can’t apply additional wet products. So let the spot wick into something else like a terry towel (slightly dampened) or even an insoluble powder.  Absorbent powders are still preferred. Damp terry towels need to be weighted down onto the fibers in order to be effective. The powder can then be removed with vacuuming.

Not all reappearing spots are wicking

Not all spots that reappear are the result of wicking. This means an absorbent compound won’t work. If a spot reappears weeks after a cleaning, it’s most likely a sticky residue.  A pH meter can determine the kind of sticky residue. Food and beverage sources have pH readings between 3 and 6; detergent residues have pH readings between 8 and 10; and oils generally have no contrast in pH from the surrounding carpet.

Reoccurring and wicking spots are mighty foes to the professional carpet cleaner. You’ll probably have to try several methods to determine what works best in every situation.

If you have any other questions about wicking spots, let us know. We’ll be glad to make a recommendation.