How to remove original windshield without breaking

[uscrichter]

I am just starting a new restoration project on a 69 Z-28 that I have had in storage for 37 years and noticed that all of the glass appears to be original and dated correctly for the car and I would like to be able to remove it without breakage prior to the restoration. I know most glass installers used piano wire , but they usually don't care about a small chip or crack since it will be disposed of anyway, has anyone used chemicals or heat to soften the seal? or have any ideas.
Thanks

[Sauron327]

 Qualified glass techs do not use piano wire as their go-to removal tool. I have a pneumatic knife and hand knives. Was your glass installed with urethane or butyl, or is it the original Thiokol with the dam? Only an educated hobby person or qualified tech would know. I deal with glass often and I suggest you contact a restoration shop or glass shop whose credentials can be verified.  For a proper installation, you need to use urethane, not butyl tape.  No experienced tech uses heat or chemicals to remove glass.

[uscrichter]

The glass has never been removed so it has a factory installed seal, what type of knife do you recommend?

[Sauron327]

One like in the link, they also have a cheaper one.  There are numerous glass tool suppliers and many types of knives and pulley systems that use cord or wire.  I generally use a glass shop who has excellent tech who knows classic cars; occasionally I remove them myself. You have be very careful so as not to chip or crack the glass.  Do not catch the glass edge with a knife. https://www.autobodytoolmart.com/equalizer-quickknife-quick-release-cold-knife-bnq271-p-33758.aspx?gclid=Cj0KCQiA_s7fBRDrARIsAGEvF8SDYmNCuXlU7hZUdy8eFoUO9VOZQsIt4MNLuULaQ3kmaGm2tRnLG8oaAqcgEALw_wcB

[77thor]

I used Safelite Auto Glass. They had a tech that specialized in older classic cars.
He removed both the windshield and back glass without breaking them (although he couldn't guarantee that).

When I was ready, he came back and re-installed the glass.

[uscrichter]

Thank you, I'll try the knife out...carefully!