Prepping Glass
Cristiano Perrucci's Method
- - hand wash for a few a minute with sponge and dish detergent
- - soak in 50% domestic bleach for 6-8 hrs
- - wash in hot tap water (~45C) scrubbing with a sponge for a minute
- - final wash in R.O. water for a few seconds
- - dry with a towel
- - final cleaning with Glassex (Windex in the USA?)
this procedure works fine for MBDCG
If I'm recycling old homemade plates, I start cleaning procedure from step 3 until all old emulsion has been washed out.
Cleaning plates is the most boring task of DIY holographic plates, I liked to minimize time spent for this crucial step.
Hans' Method
I have had great results with this method:
Previously I had great trouble with sticking gelatin to glass by silane'ing the glass with a solution of silane+acetone. I have found a new formula (from Bjelkhagens book) that seems to work much better for me. A mix is made with 40% silane + 45% Isopropylalcohol + 5% water. After 24 hours, this mix is further diluted with Isopropylalcohol to 5%. Then rub the glass thouroughly with this liquid and let it rest for about two hours. I then cleaned the glass further with glassex before application of the gelatin.
I always take 1cc of this solution and then add 19cc of IPA. The diluted solution can be used for about two days. Just rub it on a plate with a towel. You will see a white haze on the plate. I then put the plate away for a couple of hours and clean with a ammonia based glass cleaner. If you wait more than a day before cleaning the plate with glass cleaner, the white haze becomes very difficult to remove.
I have been using kitchen gloves. I also use goggles and a painter's mask with carbon filters. The undiluted Silane is nasty stuff. You don't want to get that on your skin or breathe it. Mix it in a fume cuboard if you can. I mix it always outside the house.
Adam's Methods
I soak my plates overnight in 10% potassium hydroxide aqueous/isopropyl solution (1 part alcohol per 6 parts of water) . I rinse them in warm tap water (rubbing with latex gloves - one side of the glass will make a sound when hydrophilic), rinse in DI/distilled water and wipe with towel paper until dry, wipe with a clean cloth (of silk for example) and blow with canned air. 2 days ago after such treatment, courtain coating (10% culinary gelatin, at 80deg.C), hardening in alum/formaldehyde (2 batches) and curing at 60deg.C I left my plates in DI water for 24 hours (to remove traces of a hardener). Today the gelatine is still fine and can be removed only by scratching with a nail.
I hope it helps.
The other way to clean plates would be soaking them in car battery acid solution with 10% potassium dichromate added. It worked with lab glass, but I haven't tried it for holographic plates. This mixture is supposed to be cancerogenic, so maybe it would be better to use KOH solution if possible.
JohnFP's Method
For my standard DCG I soak the plates in 5% HydroChloric Acid at least 12 hours. I then scub them with a plastic wooly used to clean no stick pans in the Acid. I then put them in running how water and scrub them again in the hot water with the plastic wooly. I then set them in a rack and before they dry completely I wipe them with a fresh clean paper towel. It is important that there is a very little moisture on the glass during this wiping. I then blow them off with air.
