Glue chipping glass problems

[Pat Whatley]

Is there anyone here who does glue chipping? I just made my first attempt at it and pretty much managed to make a mess with no chips.
Here are my details:
•Annealed glass, masked with vinyl, etched with 70 grit aluminum oxide
•Cleaned with warm water then 99% isopropyl alcohol
•Glue was purchased 8 years ago and never used. Opened one bag back then, never used it until Monday.
•Glue was mixed 1 cup glue to 1.5 cups cool water and allowed to soak about an hour until all the water was absorbed.
•Glue jelly was put in a glue pot from Letterhead Sign Supply and allowed to warm for an hour.
•Applied glue onto glass with a turkey baster because that's what I had. Some areas are a little thicker, some thinner but it's pretty close to being 1/16"
•Allowed to sit in a 60 degree warehouse for 24 hours. I wasn't expecting it to chip quickly, the temp is too low and our humidity in here is around 40%

What I found this morning, though, is that the glue is shrinking and literally just rolling up at the edges. It's not pulling on the glass as it shrinks. I can pull strips of it off the glass pretty easily and cleanly.

Does anyone have any idea where I went wrong? Is it the old glue? The blasting grit? The time?

 

[unclebun]

Too cold. You have to heat the glass. https://www.google.com/url?sa=t&rct...ip_Glass.pdf&usg=AOvVaw2fK3MwMeMRq6x3JeRsMbhg

 

[John_Smith]

make a light box - try to get the humidity way down - the lower the better.
there are books available if you want to perfect the skill. (some used books on Etsy and Amazon).
well worth the effort if you want to get the best results on a consistent basis.

 

[Ian Stewart-Koster]

Perhaps the sandblasting wasn't rough enough?
But the glue needs to be hot- at the right temp and moisture content - and not too hot, nor too cold. Each will fail.
I go around the edge with an exacto blade, as soon as it has just started to set- to separate the mask from the glue. The glue has an easier time tearing the glass out then as it shrinks and cools and dries.
1/16" might be too thin a thickness, such that it does not have enough guts to tear the glass. I aim for about 2mm - I've found too thick and the rubberiness of the glue absorbs its own tendency to want to work. Too thin and there is no strength. The right thickness and it works.
I pour it via a honey bottle or ketchup bottle.