Air seeping into side of LCD after loca repair

Hey everyone.

I've recently tried repairing a cracked iPhone 6 screen by only removing the glass and glueing new glass on with loca glue. After putting the clean LCD in a special mold for glueing and applied some loca glue in a bone shaped form and putting on the glass, I hardened the glue with a little up flashlight. I thought it had hardened completely, so I put the frame on and assembled everything back together. Now, one day later, I noticed air seeping back into between the glass and LCD from the sides, so apparently the glue still hasn't hardened completely. It looks like I pushed out the remaining glue too hard, and now it's sucking air back in because of that.

I'd like to do this better next time, so I was wondering what the reason for this is. Maybe the glue was of a too cheap quality? Or should I have used one of these nail polish drying lamps (which are much stronger than a little us flashlight)?

What type of loca can you guys recommend?

I'd appreciate help a lot,

Thanks!