Windshield Repair Forum

Jeff, how much of the seal is filled by the recomended (7 drops?) of resin? Is the inside of the seal filled about half way? almost full?

The question is just to better understand the concepts of the injector design, and exactly what happens as the plunger is inserted into the seal, etc.

Does the injector's plunger purge air from the seal as it penetrates? Thus, the plunger comes in contact with the resin with a minimal amount of air present in buisness end of the tool.

That's the only way I can figure the tool can achieve a true hydraulic action. And I assume that's the idea behind the design.

What happens when there is less resin present, such as later in the repair process, etc? Say 2-3 drops worth... Is it less effective at that point?

7 drops recommended? I guess I haven

glassdoctor wrote:Jeff, how much of the seal is filled by the recomended (7 drops?) of resin? Is the inside of the seal filled about half way? almost full?

The seal is filled with approximately 4 drops with our droppers.

glassdoctor wrote:Does the injector's plunger purge air from the seal as it penetrates? Thus, the plunger comes in contact with the resin with a minimal amount of air present in buisness end of the tool.

Well, we recommend 7 drops, so the end seal is completely full of resin. When the piston comes down, there's no O-ring on it, so air above the resin level can exit through the top of the injector. When the piston contacts the resin, it pushes those 4 drops towards the break. After that pressure cycle, a vacuum is pulled by pulling that piston through the seal (just like we did with pressure), and once the injector gets past the top edge of the seal, the remaining resin that wasn't pushed down flows into the seal, filling it again, and letting the air go up through the injector. With the remaining pressure cycles, again, you're pushing the piston directly down on resin.

glassdoctor wrote:What happens when there is less resin present, such as later in the repair process, etc? Say 2-3 drops worth... Is it less effective at that point?

There should be enough resin throughout the whole repair to keep that seal full. If the required amount of resin is not put in the injector, it will have a little air bubble right next to the piston. Is it less effective? Probably slightly.

Cool... good explanation, thanks.

I bought a Delta injector a while back to play with but the seals I had were rather stiff and I never had it work very well. I have seen the current seals and they are much softer than what I got a couple years ago so I'm sure they work better.