Delta Kits recommends that you clean your injector after every use with Denatured Alcohol. But Denatured Alcohol is no longer available in some states, in which case Isopropyl alcohol is a good second choice.
Is Isopropyl alcohol, or rubbing alcohol, the same as Denatured alcohol? Alcohol is an organic compound where a hydroxyl group is attached to a carbon atom and comes in many structures and forms.
Denatured alcohol (DA) is safe to use for the cleaning of most plastic, aluminum, stainless steel, nickel-plated, and anodized windshield repair injectors. DA evaporates very quickly, so if possible, use only DA to clean Delta Kits windshield repair resin injectors.
DA is also safe to use when cleaning all of your other Delta Kits windshield repair equipment, including lights, bridge bases, injector seals, and of course injectors. But use DA with caution on labels, logos, and other printed products.
It is also a better choice than pure ethanol because it is considerably less expensive, and a better choice than Isopropyl alcohol which contains 10%-30% water and does not dry as quickly as DA.
DA is basically ethanol with one or more added chemicals to render in unfit for human consumption. While those chemicals vary, the typical DA that you find at your local hardware and paint stores has methyl alcohol (methanol) added. The primary alcohol used in alcoholic beverages is ethanol. DA is often a mixture of about 90% pure ethanol and 10% toxic denaturants.
Use isopropyl alcohol in most of the same applications as denatured alcohol. It is safe for cleaning plastics, metals, anodized windshield repair injectors; as well as all other Delta Kits windshield repair equipment. Use DA with caution on printed products, logos or labels.
Compared to DA, Isopropyl alcohol is a better cleaning agent especially for electronics but it contains water so it does not evaporate quite as quickly. Therefore, if you use Isopropyl alcohol to clean your Delta Kits injectors, be aware that additional dry time will be necessary between cleaning and reuse. That extra dry time is the only reason Delta Kits recommends DA over Isopropyl alcohol. Note: Blowing out the injector with compressed air after cleaning in either DA or Isopropyl alcohol significantly reduces dry time.
Isopropyl alcohol is isopropanol diluted with up to 30% water. The most common type available is 70% isopropanol. 90% is available but is sometimes hard to find.
Caution: As with any industrial cleaner or solvent, wear chemical resistant gloves and eyewear when using DA or Isopropyl alcohol.
Update from September 2009 article.