How to get rid of scratches on plastic windows
Issue 35 : Mar/Apr 2004
One of the most vexing problems facing boaters is the appearance of fine scratches on clear plastic windows. The process of removing them from Lexan, acrylic, and flexible vinyl windows has some similarity to the removal of chalk from aged fiberglass. As with fiberglass, in order to bring back the original look, the scratched window surface has to be gently buffed to expose undamaged plastic beneath. A subsequent application of polish will then bring out a clear window look to the newly exposed area.
There are a few concepts to consider before you start. Always wash down the surface at the beginning to remove surface dirt. Rubbing hard particles into the plastic during the cleaning step will do more harm than good. Always use a clean pad, and don’t press down too hard until you see the results of the first pass. Avoid using paper towels or stiff brushes that can scratch more than clean.
An industry favorite for removing fine scratches is Meguiar’s 17 Clear Cleaner and #10 Clear Polish. Apply a nickel-sized drop of cleaner and disperse it using a foam applicator in a circular motion over a 1-foot by 1-foot area. Once it is spread out, rub in a linear direction for up to a minute, then wipe up the residue with a clean terry cloth towel. Repeat the process two to three times until the results you want appear. The final step is to apply Meguiar’s #10 clear polish which puts oils back on the surface, fills in the hairline scratches that reduce light refraction, and gives a protective sheen to the plastic.
Severe scratches and surface crazing are best left to a professional. Power buffing plastic surfaces looks easy but is actually quite difficult to perform without causing further damage from swirls and burning. Professionals are generally well qualified to use high-speed rotary buffers with abrasive compounds that break down into finer and finer particles under heat and pressure.
Internal crazing is all but impossible to prevent or correct. As plastic ages, the polymer tends to break down. Salt and sun add their contributions. Pressure from over-tightening the frame or an unwanted blow can cause distortion, which in turn may create internal crazing. When plastic reaches the point of crazing internally, it is probably best to replace it.
Like most other cosmetic maintenance problems, replacement can often be avoided by early intervention. Try the above cleaning and polishing technique when you first notice fine scratches, instead of letting them accumulate to the point where hiring an expensive professional is the only way to save the window.
Thank you to Sailrite Enterprises, Inc., for providing free access to back issues of Good Old Boat through intellectual property rights. Sailrite.com
