[Brent Deines]

I can't say that we have actually tested for the interlock properties of wet on wet vs wet on cured resin. I am strongly opposed to curing under pressure, but it has nothing to do with the interlock properties, however, I would guess, and it's only a guess, that you it is quite possible that wet on wet provides a better bond.

The reason I am against curing under pressure is that when the injector is applied to the glass, the pressure required to create a good seal often partially closes the cracks. So when you fill the cracks with resin the only way to know for sure if you got them completely filled is to remove the injector.

I have played with dozens of different systems over the years, and found that with many a star break will look good until I remove the injector, but when the injector is removed I will see some air in the cracks, or sometimes in the pit area. Less pressure is necessary to seal the injector against the glass when using a vacuum cup to the injector to the glass, so the problem is less prevalent than when using a system that uses one or more suction cups to mount the injector to the glass, but it can happen with any system. Therefore, I feel it is very important to swivel the injector away from the repair if the system allows, or remove the injector completely if necessary to inspect the repair prior to curing.

What this does is allow the windshield to return to it's original state prior to curing. Not only does this allow the technician to make sure all the air is out of the break, but it also removes the stress that is placed on the glass from the pressure of the injector. I believe some systems are incapable of getting all the air out of the break, so they must cure under pressure, but I feel this is cheating, and does not provide the best possible results.

Repairs can also be completed faster if they are not cured under pressure as there is the curing light is applied directly over the break, and the second curing step is eliminated. If the interlock properties are better as well, that is just one more reason not to cure under pressure.