On 5/2/2013 8:38 AM, Sonny wrote:> On Thursday, May 2, 2013 7:28:16 AM
UTC-5, Leon wrote:
> > I do not the exact reasoning other than how it was explained to
me by my instructor some 30 tears ago. Glass is technically a liquid vs.
a solid, it heals itself. I have never verified the next example of
glass being in a liquid type state but it is said that the stained glass
in old church windows is thicker at the bottom and thinner at the top.
> Yep, at room temperature, glass is a super cooled liquid. Almost all
glass 75yrs old and older will be visibly thicker on the bottom, with
waves/wrinkles (flows unevenly) that will noticeably deflect light.
> Glass exposed to UV light for ~~75yrs starts to turn blue, has a blue
shade to it, only noticeable with clear glass, i.e., an aspect to help
in dating/aging glass, bottles, jars, etc.
Ah yes! I had almost forgotten that the light will trun in color when
exposed to the UV light.
AAMOF my grand mother and aunts collected old looking clear glass
bottles and placed them inside a wooden box lined with aluminum foil.
They used a florescent UV lamp on the lid to constantly shine for
several months. At the end of what seemed 3~4 months the glass would
actually have a purplish cast.
A funny note, my grandmother in her 70's back in the 60's would watch
the process with the lid partiality opened, no knowing that the process
was going to take a long time. She ended up with a sunburn around her
eyes. Not bad, just enough to appear really odd. LOL
> I assume this info is fact, learned as a self taught amature bottle
collector, back in high school and a bit beyond.
A correct assumption although the artificial process yielded the
slightly different color.
> I've always understood cutting older glass panes may not always
cut/snap clean, because of its unevenness.
> No telling what other mistakes I made, besides 1) scoring too hard,
then 2) pausing before snapping, to inspect that the score mark was
visible and, if not, score it again. <---> What was that thread,
"Pretend you know an idiot"? Ibid.
I mentioned immediately, What i should have indicated was don't score
all of your glass and then break it. Breaking is the very next step in
the process of cutting. Basically don't score the glass until you are
ready to snap it. Also do not rescore, run the glass cutter in one
continuous fluid motion. Only press hard enough to hear the cutter working.
And then cutting concave curves is another matter altogether. You do
need to score the curved shape and then make several relief cuts to
slowly remove material up to your desired curve. And grozing plyers are
involved to literally break out chunks.
Much more fun cutting a convex curve.