Glass
Yesterday I had some free time so I decided to try my hand at cutting some daguerreotype cover glasses. I plan to make my first daguerreotype attempts at sixth plate size using the Becquerel process, so I was going for 2 3/4″ by 3 1/4″ covers. I have had past experience cutting large pieces of glass for window repairs and I have not had much trouble with that, so I figured that it would be an easy project. Wrong. I find that cutting little pieces of glass is much more challenging than big ones. I started out with a 12″x16″ piece of single strength window glass and managed to get only 6 intact cover glasses. That was a 70% wastage rate! Now admittedly the glass piece only cost USD $2.32 so the cover glasses were roughly USD $0.39 each, but I should have done better.
I did learn a couple of things in the process. In the past I have had some trouble holding a steel rule and making a straight cut on glass at the same time. It is slippery darn stuff. I have a small Logan mat cutter and found that it made a great way to hold the glass steady and get it lined up just right. Pictures here.
I also learned that there are differences in glass cutting tools. I have a glass cutter made by Fletcher that has been floating around with my tools for about 25 years. It was a bit rusty, so I went over to Lowe’s and bought a new one for USD $3.48. It was from a company called “Kobalt” which may be a Lowe’s House Brand. The head of that thing looked just like my old cutter but the resemblance ended there. That tool couldn’t cut worth a damn. As an act of desperation I tried the old cutter and it did quite well. Well enough that I knew the problem had not been entirely my technique.
I imagine future improvements in this task are probably mostly a matter of practice, but I think I will head over to Dagforum.com and see if any of the more experienced members have any tips to share. I also remember seeing an interesting tool for lapping glass edges on the AngelGilding.com site.
Daguerreotype Process | andy | November 30, 2008
cover glass, cutting glass, daguerreotype, daguerreotype process, lapping glass, Plate preparation, Plates, polishing
Hey Andy
Glass cutters that have oil reserviors within the handle cut better: http://www.maplecityglass.com/tools.html
I find that if you can break the glass over a hard straight edge (table edge) along the cut line on the glass within 2-3 seconds of making the scribe it will break easier, after that time the glass knits back down and the break is harder to make.
When I gave a talk at Eastman recently the conservators had much to say on glass, they seem to prefer pyrex glass in sheet form – it is white glass (no green tint). this is nicer to view dag plates through, the green tint comes from the iron oxides in the glass. To get no tint glass (“waterwhite”) arsenic has to be used to remove the oxides making it expensive and not environmentally friendly.
Thanks for the input Alan. I had no idea there were so many kinds of wheel type glass cutters! I was looking the other day at one that had a diamond in it. I notice that they aren’t shown on the site you gave the link to. Perhaps it is one of those things that seem like a good idea but isn’t.
I am curious if you have looked at the water white glass next to standard green glass? Is the difference that noticeable? Or were there other reasons they favored it besides the visual?