I think what you are looking for is blunt cannula needles. They are used to draw up only. I work in a hospital so there are many around. I keep the needles that I have used and are still clean (I have only drawn from sterile sources.) I find however that if you are using them to inject into bubbles the injection needles work better. There are several different sizes. Someone was saying to cut the needle off with wire cutters then hone the end flat on a stone. That is fine but unnecessary. Use a larger needle. I have tried 23 gauge, 21 gauge and 20 gauge. The lower the number the larger the needle (like a shotgun). If you get a 20 ga. needle you should have no problems with getting flow through the needle. Plus, the sharp tip cuts out the step of having to place a hole for the needle first. The sharp needle does this itself. One last thing. if you can, get long needles. I found that it is easier to get resin into long bubbles by setting the needle far in and withdrawing it when the areas are filled.

just some suggestions...