Yeah it’s getting pretty crazy here in Cali water wise. Then again…what can anyone do?
As for methods to remove silicates an HF or CC-550 would be an option for me after confirming what surface the stain is on tin or air side. If it is a true silicate and after trying other products not detrimental to float glass.
Sodium silicate is added to “increase the finished water pH thereby reducing the corrosiveness of the treated water.” (retard erosion)
Why exactly are we concerned that sodium silicate is added as a conditioning chemical in such small quantities (e.g. maximum recommended 100mg / l; actual 2-4mg / l?) I know I’m not a chemist – I don’t know that the conditioning properties are directly related to hard water stain/silicate issues. Is that the only reason silicates form (doubtful)?
And, it doesn’t appear to be a strictly California craze:
“According to the EPA’s 1991 Lead and Copper Rule (LCR), water distribution systems are required to have corrosion control measures completely installed by January 1997 for large systems (> 50,000 people), by January 1998 for medium systems, and by January 1999 for small systems (< 3300 people).”
There are basically 2 ways silicates become an issue,which i explained in an earlier post. As for the amount… (from tratment facilities)it has very little to do with it because it continue’s to be an on-going problem with sprinkler water,as well as other water sources.
Basically…if it wasn’t an issue we’d only be dealing with 1 form of silicate from “un-treated” pre-cast.Unfortunately that’s not the case.
I did read your earlier post.
Can you please provide a link that scientifically attributes the silicate stains on glass to the usage of sodium silicate as a conditioning chemical in water treatment distrinution systems?
No link sorry! Only what Dan Fields relayed to me in regards to differentiating the 2 sources of silicate deposits on flat glass.
Does Dan have that documented in any written documents?
I would think so Lar. As Dan’s one of those guys who likes things to be properly grounded in fact.
Maybe you can get a copy posted here the next time you contact Dan.
Dan could not find the link he had but…reiterated that regardless the amount used at water facilities silicate deposits will continue to pose problems for window cleaners.
Furthermore i am awaiting contact from a higher source which i will relay to the group when i get it.
In the meantime…this is an article from Paul Duffer renowned expert in the field of both glass corrosion & silicate deposits.
Clearly hits on how detrimental silicates are on flat glass,towards the bottom of the article.
http://www.usglassmag.com/USGlass/2001/0105/whathappened.html
