by David Eaks » Wed Oct 08, 2014 9:40 am
Here is a video I made showing the process of making water glass. This batch was just the last of my ingredients, so not exactly sure of the amounts (about half of the usual batch). The usual batch was 1000 milliliters of water, 400 grams of lye and 600 grams of silica gel. This makes 1000 milliliters of silica gel (1+1=1), or less if you take too long, boiling away trying to get big chunks of silica gel to dissolve.
Although, I have usually ended up with some extra silica gel, about 50-80 grams, by the time the mixture is getting pretty thick. Continuing to add silica gel past a certain point will make the water glass so thick, that once cooled it won't pour out of the bottle. Warming it will help get it to flow. I have combined and heated a batch that was too thick into a batch that was in-progress, seemingly without any problems.