Curing under pressure.

[splitpit]

How many of you utilize this procedure from time to time and why?

[jayjacque]

I'd like to understand that more also. I never do. When finished filling I usually move the bridge off the repair and put curing tab on in one quick motion. My thinking has been if I can get the curing tab on quickly there is no chance of air coming back into the break. This was kinda self-taught so definitely not the voice of an expert. If I'm wrong (which I might be), then somebody please tell me when should you instead cure under pressure?

[splitpit]

How do you use one quick motion and get pit resin in place?

[Mr Bill]

Are you using pit filler?

[splitpit]

If you are not using pit resin and your are simply covering up with a tab and curing you are skipping a vital part of windshield repair that will most certainly effect the long term appearance of your repairs.

[jayjacque]

I get the tab on right away without pit resin. Let it either completely cure before putting pit resin or more often than not let it half cure and slip the pit resin under the tab. On the simplest bullseyes when or how you get the pit resin in doesn't seem too crucial

[splitpit]

Brent correct me if I'm wrong. Don't you lose some of the chemical interlock that you need when you cure your windshield repair and then go back and add pit resin over it? It has always been my understanding that you leave a thin layer of windshield repair resin in the pit and then add the pit resin over it, then cure. Isn't the chemical interlock the most effective when the uncured windshield repair resin is in contact with the uncured pit resin before curing?

[splitpit]

That chemical interlock is what gives extra strength to the pit resin itself and helps keep it from deteriorating over time or loosening and coming out.

[splitpit]

I kind of see it like this. By curing you windshield repair resin first and then going back and curing pit resin over it, it's kind of like pouring a concrete slab and allowing it to dry and then pouring a second layer of concrete over it and allowing it to dry, with the expectation that those two slabs of concrete will stay bonded togther. Over time, especially as they age or are driven over (wiper blades) they are not going to hold up well.

[screenman]

Whilst I agree with what Splitpit is saying, in fact Novus used to issue a black spot tha you would stick over the pit whilst curing the resin. This kept a damp spot ready for pit filling. There are some times when I would C.U.P Usualy when the starbreak would have a legs that is open to the surface, this I would treat by laying on some Magnibond resin along the leg, placing a tab over the top and flexing from inside until full. I would then cure this break under pressure. As there is a good chance swinging the bridge away would suck some sir in. Now this way of curing would still leave the desired damp patch under the injector ready to accept the pit fill resin. Also I sometimes C.U.P those real big breaks that you get on truck screen as I have found removing the injector on a really large break with a big pit will allow resin to escape if not cured. Before I get jumped on I do not mean all the resin but enough to spoil the job. As I see it C.U.P is just another tool to be used when required.