injecting is one of the techniques mentioned here and elsewhere abt filling bubbles in glass. And i have been using it big time on my recent layup that has abt a quadrillion or more bubbles. (of which 1/2 would not have happened if i’d followed some of the advice and ordinary common sense given out here!)

my method was using 10cc syringes w/ the small plastic tips and forcing the tip into or onto a tiny awl/pinprick hole i made in one end (or low end) of a bubble with also a light pin/awlprick in the other end to allow the air to escape. often works very well, but some bubble lines needed all the injection pressure i could get or more, but the tips would deform and often wouldn't work under this extreme pressure, leaving some questionable areas and more visible crappy hack repairs from making larger and larger awlholes to actually fill the voids.

to try out something new, i bought 100 (couldnt get less, but only $7 can.) #20 gauge steel needles w/ a few accompanying 10cc syringes to fit. i ran the tips back and forth on a sharpening stone a few min to make a flat across blunt end(not the acute angle they come with).

these work easily 10x better than plastic tips. often i can just firmly press the blunt needle tip against the outside of the glass over the awl/pin prick and it sort of seals to allow the resin to infiltrate the desired area, and of course i can get the pressure farther into a smaller hole diam of the needle (vs the plastic), i can use more pressure w/ less wastage, and over small fields of thin bubbles i can make multiple pinpricks and just press the needle on the outside of various pinprick(s) thereby ‘sealing’ the syringe needle to the hole and often still fill the cavity areas.

i don’t know ultimately what it’ll all look like, but now parts of this worst glassing episode of all time of anybody here will be one heck of a lot better than it was, due no little bit to the use of metal needles.

-mick