CONCORD, N.C. — Oh, those yellow stains. You cannot assume anything about a yellow stain with a quick glance. Inattention or inexperience can lead you down the wrong path in attempting stain removal. But, with proper technique and by knowing the things to look for, a cleaner can make the proper identification. Once the origin of the stain is confirmed, removal is a matter of applying the proper protocol.
These yellow stains may look the same upon first glance, but they are not. Some of these stains are the result of sugar from fruit, a beverage turning dark over time, or with the application of heat. Some of these stains are the result of contact with a fresh beverage. Some are the result of light oils and greases being left untreated for a period of time. This last group of stains (oxidized oils) is one of the most difficult stains for a cleaner to remove.
A slice of apple, left uneaten, will turn dark if left exposed to air and heat. The sugar in the juice has caramelized. A clear beverage such as champagne will turn dark in the customer’s closet or during the drying portion of your drycleaning cycle. The stain will seem to appear out of nowhere, but it was there all the time. Many times, especially in post-spotting, the area will be removed simply by applying steam over the vacuum nose of the spotting board.
The first step in wet-side spotting protocol is to flush with steam, apply neutral synthetic detergent and light mechanical action, then flush with steam. In four out of five cases of caramelized sugar, the stain will need no further treatment. If there is a trace of the stain left, apply your tannin formula and light mechanical action, then flush the area over the vacuum nose of the board. In extremely old caramelized sugar, it may be necessary to spot-bleach the last traces with hydrogen peroxide.
If after flushing the area with steam for the first time (as described above), there is little or no noticeable appearance change in the stain, the stain is probably not caramelized sugar and should be considered a classic tannin stain.
The wet-side protocol remains the same: flush with steam, NSD, flush with steam. Tannin stains will take a little more time to remove, but will eventually be broken down and removed by an acid-based tannin formula.
There are many chemical tools that can be used on a tannin stain. You should move from a mild tannin, to an aggressive tannin, to general formula, to oxalic acid. If traces of the tannin stain remain, neutralize the area with an alkali or protein formula and spot-bleach with hydrogen peroxide or sodium perborate.
An oxidized oil stain is recognizable by its unique shape. Look closely at the edge of the stain. If the edge looks ragged and forms “crosses” as it trails away from the stain, it is probably oxidized oil. These crosses are caused by the oil wicking along the yarn, but is too thick to cross between yarns. The age of these stains make them extremely difficult to remove.
The first step in removing oxidized oil is to treat it as a dry-side, chemically soluble stain. Apply a POG to the stain over the solid portion of the spotting board and then tamp as vigorously as the fabric will allow. If this treatment results in improvement of the stain, repeat before dry cleaning. The stain has already become ”set” over time, so the heat of drying will have little, if any, further adverse effect. After dry cleaning, inspect the item for progress in removing the stain. Repeat the procedure described above until there is no identifiable improvement in removal. If you are one of those cleaners who still keeps “a little” VDS around, oxidized oil is the time and place to use it.
At this point, there are two further courses of action available. The most common action is to resort to bleaching. However, a mixture of butyl alcohol and potassium hydroxide has been shown to be highly effective on oxidized oil stains. This is commonly referred to as KOH solution.
This chemical tool is not commercially available, so it must be formulated locally by mixing 9 grams of potassium hydroxide dissolved into a quart of normal butyl alcohol. The shelf life of the solution is almost indefinite, so once you mix the solution, it will last for the foreseeable future.
Apply the KOH solution to the stain on dry fabric. (KOH is a strong alkali; never apply KOH to fabric that is or may be wet.) Allow the solution to penetrate the stain for a period of six to eight minutes. You should see the stain begin to break down. Flush the area with a dry-side leveling agent and then dry clean.
Removing an oxidized oil stain is something many cleaners are not willing to attempt. Therefore, it gives you a chance to validate that you are just a little better than the other cleaners in your area.