Okay I have the biggest problems with these things. I use the 3600 but I always end up with what looks like cracks or airbubbles once they dry.
do you see the airbubbles? I try pushing down as hard as I can. I try moving the glue around and trying to press the airbubbles out.
Is there some kind of secret I don't know about?
I can't see the air bubbles in your picture. But I've had a problem with little streaks muddling the tiny images I've glued to glass marbles. Something caught my eye the other day when I was reading Durwin Rice's New Decoupage
. One of the earliest projects is gluing a picture on the backside of a glass plate (so you see the image through the glass). He points out that though you don't want too much glue, you should be using glue that dries clear. Therefore, you don't want to be squeezing as much glue as possible out--it's not the glue that's making the streaks (and air bubbles, I imagine), but places where there's no glue
in between the picture and the glass.
The solution is to make sure that you leave a complete layer of glue and gently work bubbles to the edges with your fingers or whatever. And magically enough, none of the picture marbles I've made tonight have streaks in them. They just take longer to dry... I just use regular ol' white school-type glue, which is of course opaque at first, but becomes clear as it dries--the marbles are like slow-motion polaroids.
Oh, one other thing that seems to be helping--in the same book, Rice is a huge proponent of soaking your images in water to "relax" the paper. It wouldn't work if your picture were on photopaper or printed on an inkjet, but I typically use magazine and calendar pics and letting them float on a little dish of water until they stop curling up works great. Just lift the image out of the water, shake excess off, and push facedown into the glue.
If I were less lazy, I would provide you pics of my thrilling, streakless picture marbles.