I've drilled a few of those blocks and I would say they are 1/4 to 3/8 of an inch thick. It took quite a while to get thru them. I had the best luck when I put the block in a plastic container and covered it with water. It kept it cooler and I cracked fewer of them.

Good luck and let us see what you are making.

I have made over 70 glass blocks now and I have 15 more I need to get on. I do not use water I just sit on the floor and drill with my mason bit.. I have only used two bits and only cracked 2 blocks early on and they were not cracked bad enough I could not use them for family... The only good advise I have is make sure the brick is room temperature.. The ones I cracked had been in the car and were very cold when I drilled them... I also put my hole on the bottom side of the brick... Good Luck they are so much fun... grace

When you are done painting your blocks and you go to seal them. What are you using to seal them??? I am using just regular acrylic paint, because I have a big selection of it.....but once in awhile after I seal it, I notice the paint will chip off. Is there anything to help this not to happen?? Thanks so much.
Misty

I just watched Donna Dewberry on painting on glass. She has special paints that she uses for glass and then sets the paint by baking them. I'm not sure of exact temp. You could possibly try painting a beginning coat of satin gloss, then paint what you want to and let that dry and finish off with another coat of satin gloss varnish. Just a thought.

I do some decorative painting, Donna Dewberry One-Stroke Style. The "special" paint Luelue is referring to is "enamal paint." Use a "glass medium" when painting on glass with acrylic paints as it is hard to get the paint to stick without it. You will find the enamel paint glides on more evenly than acrylic. Pick up one of her Painting on Glass books and check for the amt of time and temp to bake glass. Usually, after 21 days (without baking) and it will be fine.

An FYI on drilling the blocks... I was told by a fella who works with these blocks on a steady basis. He said they always lay the blocks out in the sun to warm them up first. I just put them in the trunk of my car and drive around with them in our 90* plus weather and they are good to go!

hello everyone, I was wondering where I can find the glass blocks with the holes already cut in them. Thank you