glass fines: what are they?
glass fines are airborne debris, dust, dirt, and / or tiny glass particles that become fused, (baked into), glass during the process of tempering. the result – window glass has microscopic “bumps” that create an uneven surface.
why are they dangerous?
the uneven glass surface, laden with solid matter, can easily become lodged under glass scraper when performing routine window cleaning, construction cleaning and over-spray removal, causing potentially deep scratches to glass surface.
obviously, this can become a serious liability issue for the professional window cleaner who, more often than not, gets blamed for damage that could have easily occurred “before” he or she has performed work on the effected glass.
how to detect?
because glass fines are generally invisible to the naked eye, touching the glass – prior to using a scraper – is the best way to detect fabricating debris before potentially damaging glass surface.
you should (but not always) be able to feel the tiny pimples of the fabrication debris even when you can’t see them. this raises the question: “who’s responsible for damages when glass fines get caught under a scraper blade and scratch glass”? is it the window cleaner or the glass manufacturer?
when using a scraper, to remove over-spray, always test blades reaction to window glass in a small inconspicuous place, such as a corner of the glass. glass fines will have a “gritty or course sound” when scraper moves across glass.
if you hear this, stop scraping!!!
you’ll want to choose a different method to remove paint over-spray and other construction materials such as, via a “0000” grade steel wool pad or with the use of the appropiate chemicals.
can you get a refund for glass you’ve purchased containing glass fines?
probably not. since glass fines do not effect the structural integrity of the glass and are not a hindrance to glass clarity, the glass will usually meet industry standards for heat treated flat glass.
this again questions the idea of “who is responsible”? if you are a home owner and you follow your window scraper’s manufacturers guideline to scrap glass and as a result you damage the glass surface because, the manufacturer of the glass has provided you glass with fabricating debris baked into it’s surface.
shouldn’t this be cause for due negligence on the window glass manufacturer? shouldn’t they be liable for replacing your glass?
professional window cleaner’s – “damage waiver”:
if you are a professional window cleaner providing a construction cleanup window cleaning service, you should strongly consider using a damage waiver to legally excuse your company for damages that may or have already occurred before your service commences.
afterall, glass fines are very difficult to detect, making it easy for you or one of your employees to accidentally damage a clients window glass surface.
also, scratches and other damage may already be present on glass surface but, not noticed until “after” you’ve cleaned the glass. this is obviously damage incurred by a previous contractor, or during shipping/ storage or manufacturing of the glass product.
unfortunately, you may be stuck with the bill so, get a waiver signed before performing construction cleanups and other related work that could expose your company to liability issues. check out my article on post construction window cleaning for more info.
Side note: currently, there is a huge debate over “who is responsible for scratched glass”. generally speaking, professionals in the window cleaning industry would like to see higher standards in the processes in which tempered glass is manufactured.