I am willing to go to clay or mortar...just wondering how close the bottles can get.
All depends on the method and the wall it goes into...There are just so many ways...some good...some not so...
I have seen a product called "gorilla glue for glass"....would I be able to get by with putting the bottles in touch with each other and then filling in the gaps with clay/lime/etc?
Could work...I would suggest a 'hot glue' system for the primary construction building these units over something like 'gorilla glue' if you really are going for them having the thinnest bond layer. They the unit could be set up with the face of the bottles up, and grouted with black lime grout or even a matrix of epoxy or other glue type mixed with sand as the grout (if modern materials is the goal method wanted.l)
I would like to find some way to turn the filling black, to make it look a bit like stained glass.
Then I would cut the bottles up as this is the traditional method and "cane them" proper just like stained glass bottle windows are normally done...I have made both these and "bullseye glass" eve a one from "Heineken beer bottles." If interested...find a
local glass blower and have them teach you the basics and pay for some shop space to do a
project...
I have seen glass blocks (bricks) that can be used but they are a little pricey, and there is no sense in paying a premium price for something when something can be reused for almost free. I would imagine that, to protect from water and elements, if the bottles can be glued together, silicon might be necessary because it would expand with temperature changes...but I could be wrong.
Silicone is a way...it is not really necessary unless working with something like a fish tank...
I want to be pretty certain of this because this windows is (most likely) going to go into a straw bale house.
Good for you...These, if the building is well planed and designed are something that can be fabricated ahead of time to save in the actual build time there by shortening the "turn key" of the project.
Regards,
j