With steel frame, 2 sheets of 1/8"+ ceramic glass, heat resistant tempered glass. If you put an o.d.#8 filter in front of this, you could weld through it or for student viewing or observer. John in Eagle River by Fred Meyers ak text 242-83two4. This glass and frame out of a Frigidaire oven that was exposed to a hot! Fire. 20 bucks for 2 glass panels and the frame. I washed the glass and frame but it needs a razor blade scraping to remove the buildup. Also your idea, high temp glass for a stove fireplace or brazing chamber?
Your idea. As pictured, I tried to get the purple 🟣 reflection in the picture.
(I scraped off the crud with a razor blade scraper, needs a little Scotch Brite yet.)