A Solvent Situation: Gum Gone Bad
January 8, 2013
“Jessika, I received a phone call from a commercial carpet cleaning project I was on last week and they want me to replace the carpet. Please help me!”
I often get phone calls and e-mails from cleaners that are having issues removing spots from carpet and upholstery. On a recent phone conversation, a technician was describing an issue he was having trying to remove gum from a commercial grade olefin carpet in a nightclub. After a lengthy discussion he explained to me his gum removal process: He was squirting a liquid “gum remover” directly onto the carpet, letting it dwell, then using a bone scraper to pick-off and remove the gum. Then he would extract the area with hot water. He was able to remove the gum, however, he now had “bubbles” in the carpet, tufts were popping out and the carpet had rapidly re-soiled just after a few short days.
“What had gone wrong?” he asked me.
After doing some research on the “gum remover” product, I ascertained that he was using a liquid non-volatile dry solvent – overkill for a gum spot – and a spotting agent that can cause considerable damage to carpets if not understood and used properly.
Any chemical that dissolves another substance is called a “solvent,” however, in the carpet cleaning industry when we discuss solvent spotting agents, we are usually referring to “dry” solvents - a formulated chemical cleaning or spotting agent that contains no water. Dry solvents will break down and dissolve solvent soluble soils such as oils, grease, tar, resins, adhesive residues, oil-based paint, many cosmetics and gum. Citrus-based and blended solvents (sometimes called “wet” solvents) are formulated into our professional grade pre-sprays and used as pre-spray boosters. In gel form, wet citrus-based solvents are used as carpet and upholstery pre-spotters and gum removers.
In order to properly remove solvent soluble soils without causing textile damage, a cleaner must understand the several different formulations of solvent spotting agents that are used today:
- Non-Volatile Dry Solvents (NVDS): Sometimes referred to as paint, oil and grease removers (POG’s), these dry solvent spotters take an extremely long time to evaporate, and when used, must be followed with an application of volatile dry solvent (VDS) spotter. NVDS’s are not commonly used by cleaning professionals, as for most situations the use of a NVDS is overkill. Non-volatile dry solvents are used to remove dried oil-based paint, ink, nail polish and lipstick. And that’s about it! They are never applied directly to the carpet, but rather are applied onto a clean white towel, then onto the carpet by using a spotting brush and a tamping motion – a gentle up-and-down hammering motion on top of the towel that has the NVDS on it.
- Volatile Dry Solvent (VDS): In this case, “volatile” means to evaporate easily (and quickly!) and are formulated to remove non-volatile dry solvent residues, grease, oil, tar, asphalt track-off and adhesive residues. They are applied the same way NVDS’s are – onto a towel, then gentle tamping.
- Blended Solvents: These citrus-based solvents are specialty “wet” solvents and they are formulated to be removed with a solution of hot water and professional extraction detergent. They are available in liquid and gel form. Liquid citrus-based blended solvents are often added to carpet pre-sprays and are excellent pre-spray boosters. Blended citrus-based solvents in gel form are used as pre-spotters and gum removers. They must be thoroughly rinsed from the carpet with hot water and detergent solution or rapid resoiling will occur.
In the cleaning situation that that was described by my caller, he had used an NVDS improperly. A quality formulated citrus-based blended solvent in a gel form would have given him terrific results without the delamination damage (the bubbles and loose tufts) caused by dripping the NVDS directly onto the carpet. His second mistake: He did not follow the NVDS application with a VDS application, therefore leaving an invisible sticky residue on the carpet that will cause rapid resoiling for some time.
Follow these steps for great gum removal – guaranteed:
- From your local distributor, purchase a quality formulated citrus solvent in gel form. There are some really great products available, so talk to your sales representative, or another carpet cleaning buddy and get a recommendation.
- Some cleaners like to soften the gum with warm detergent solution, but I usually just poke several holes into the gum with the sharp pointy end of a spotting tool.
- Apply the citrus gel directly on top of the gum, making sure that the gel does not get onto the surrounding carpet fibers.
- Allow dwell time. For some of the quality citrus gel products all you need to do is wait about 10 minutes. Even for the gum spots that are black, flat and ground deep into the carpet fibers.
- After allowing appropriate dwell time, the gum will soften. Then extract the area with a hot detergent solution. The dissolved gum should just disappear up your wand! Flush and extract that area thoroughly, as many of the quality gel products can leave a powdery white residue if not properly extracted, or resoil rapidly.
It is important that technicians take safety precautions when using liquid dry solvents: Wear proper protective equipment, such as solvent-resistant gloves, protective splash eyewear, a vapor respirator and make sure there is adequate ventilation. Liquid dry solvent spotting agents, such as the “gum remover” above, should be used in appropriate small quantities and never used for overall cleaning as there are health and safety issues associated with solvent vapors and delamination can occur if not applied (or removed) properly. Many dry solvent agents have a low flashpoint (the temperature at which solvent vapors ignite) and possible explosion is a serious concern. (Again, this is another reason why dry solvent spotters should be used carefully in small amounts only and never for overall cleaning.)
In the case of our caller from above, unfortunately he did end up replacing the carpet, but luckily it was a hallway and it only cost him $300.00. On the up side, on one of our last conversations he said, “I now know how to properly use solvents. This learning experience will make me a more professional carpet cleaner and help me to serve my customers better!”