Mafsu, I use GlasWeld injectors and have used GlassTechnology and U.B. injectors. And, No.. You cannot tell merely by feel that the injector is too tight against the glass. With time and practice you develop a feel for it. But using your sense of sight as well as touch, you will learn that correct pressure needed. For sight, when placing the injector, you want to visibly see the seal touch the glass and not tighten so tight that the seal almost disappears. When the seal touches the glass, go maybe 1/2 turn more, release resin pressure slighty and look for seepage, if none you are ok. If it does seep slightly tighten enough to stop the seepage. You will find the breaks fill faster and easier using the right amount of head pressure. Good Luck..

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