WPSC

Greetings,
Glass cleaning is an essential step in the restoration process prior to re-installation. Smaller panes can be safely soaked in a tub but I clean large panes one by one 'on the bench'. Though I resist brand names in favor of homemade concoctions I continue to use 'windex' as it seems to soften paints and attached glazing compound. Occasionally a bit of applied heat with a heat gun (low temp) and careful 'wet' razor work will clean the edges. Sometimes old glass has been previously scratched by over enthusiastic painters-we certainly do not want to add our marks to the historic record

Essentially, cleaning is a chemical process, and chemical reactions take place more rapidly when there is more heat. Heat can be effectively added to the glass cleaning process by:

Raising the ambient temperature of the work area, with a wide gentle flow of warm air. (which can also aid it drying the glass)

Arrange the cleaning bench so the sun shines directly on the glass. (which also aids in seeing the dirt on the glass)

Apply heat to the cleaning process with an infra-red lamp. (which is less likely to crack the glass than a hot air gun)

_________________
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

Soaking the glass for a day to two is pretty effective. I use a mortar pan to soak glass. It is large enough to accommodate most panes. The solution is about 20% Simple Green and 50% water. It releases the glazing and makes cleaning the remaining glass crud fairly simple. There is no magic bullet here, it still takes a fair degree of elbow grease to get the job done.
Don't be over aggressive or you will end up with two pieces of glass. :(

Hi Tom, welcome to the Collaborative!

I've used soaking for several years, and it is really worthwhile to soften up the hardened grunge.

I soak smaller panes in a 5-gallon bucket, vertically. I had trouble with breaking larger panes when I tried soaking them in a flat tray, so I now soak all panes vertically. A small chest freezer appliance that has quit working as a freezer is handy for this purpose and usually available at no cost, they are usually water tight and even have a plug at the bottom for draining the water.

We're working on a standard for cleaning glass right here in this discussion. Any further cleaning tips or methods?

_________________
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

Also, steam works, faster than a soak. I mist the removed panes with cleaning solution before they go in the steam box. The steam softens up the crusty putty and paint around the edges. It must be cleaned off immediately after removal from the steam box, while the putty is still hot and soft, just a few or several minutes to work on it.

_________________
John
Standards Co-Founder
Standards Editor

http://www.HistoricHomeWorks.com

I have had better luck cleaning the large panes, that cannot be soaked, using Dirtex.
It seems to be more effective and quicker than the usual off-the-self window cleaners...
It's all about production, anything you can be do to speed up any phase of a restoration process means a few more kopecks in the kitty.