curing under pressure

[desertstars]

Curing under pressure simply means exposing the filled repair to UV light while the injector is in a pressure cycle and is still in place on the repaired area.

Why is pressure-curing important???

The act of curing itself releases heat and releases gas. (It's exothermic.) Curing under pressure stops the generated gases from collecting which can result in forcing or pulling resin back from tight fractures.

Not to mention that phenomena called gravity on ANY resin injected into a windshield repair that isn't forced to remain in place until hardened. The second one relieves the pressure on an uncured repair, that resin is going to drop just like Newton's apple.

(Assuming of course that one hasn't removed the windshield and layed it flat on the ground before commencing the repair.)

I cure under pressure.

[2hipp4u]

Hi Desertstars

Do you cure all breaks under pressure or just nasty stars and combination breaks?

I am also curious as to how you place your UV light on the repair, do you place it in one spot or do you cure for a minute or two in one spot and then continue to do the same around the injector?

I have been moving my light around the injector in three positions for about two minutes on each position and it seems to work fine, but was wondering if maybe I am spending to much time on it.

Thanks

2hipp4u

[desertstars]

Hey, Zhipp4u.

I repair ALL repairs under pressure assuming that if heat was applied the w/s is cooled back to normal.

NEVER cure under ANY circumstances until the w/s returns to the ambient temperature.

I hardly EVER need to use UV light here in Arizona and with very few exceptions ever repair at night under artificial light.

Your method of moving the UV light is fine depending on the strength of the battery and the bulb.

Could be overkill though depending on the configuration of your UV light attachment.

Normally, attach the UV light close to the repair and direct the reflector.

Just be very careful that you don't apply too much pressure or suction on the UV lamp when attaching or detaching it from the windshield while relocating during a repair.

Any movement on the w/s during the curing process will affect the repair outcome.

Sounds like you are doing a good job.

Others may have other advice.

[glassdoctor]

Ok, my $.02 I don't normally pressure cure.

I don't experience any problems with removing the equipment and then curing. If the repair is done right... actually 100% done... there is no need to pre-cure before removing the injector. I don't ever see resin escaping, air getting in, or shrinking resin leaving air pockets, etc... none of that at all. But that's just me... apparently others have had such problems.

But sometimes I will use pressure curing if there is an "issue" with the repair, like a stubborn little spot that is eager to reappear when not under pressure. And sometimes I will do it just for the heck of it... works fine too. I have no problem with pressure curing, just choose not to make it a habit. I see it as a waste of time in most cases.

One thing I don't like about it is that it does make the "daisy" line a little worse, almost always. It's just a fact, at least in my experience and the way I do things. That nice fine halo of a bullseye will become a nice but thicker halo if it's allowed to cure under even moderate pressure. If you stop the pressure and then cure, the halo does not change. Same with other breaks too... but it's not a big deal or anything... it's usaully not even noticable when it's all said and done. So I'm not bashing it at all...

Sometimes it's just a neccessity, and the lesser of two evils. It's much better than having a spot not filled...

[Repair1]

=D> WOW!!! Desertstars you have done a fine job of explaining cure under pressure shouldn

[glassdoctor]

Repair1, you are right... a hot w/s would greatly increase the daisy thing. But I don't work on hot glass... you can get a daisy on hot glass no matter what methods are used.

I don't mean daisy in a bad way... but rather the "good" daisy.

At room temps and normal reasonable pressure... I have observed a slight increase in the daisy line if I cure while under pressure. Just my preference.

I guess it comes with experience, but I don't ever do this #-o because I didn't pressure cure. I know when done is done.

[Coitster]

I always cure chips under pressure. I also carry an e-zup tent with me and I through it up over all cars when its over 80 degree's outside because in direct sunlight they are over 100 degree's. Lets the windshield cool down and works better.
David
Coitster

[Mark]

Dave and anyone else,

Do you have your ez-up on wheels so it goes up quicker?
what about sides for it? I was thinking about sides on the ez-up when I I set up and hang a sign.
Also for bad weather it would keep thing cleaner and dryer.

Sams Club has them for about $185.00

BTW I will be spending the day on monday with Chris aka MAFSU. Then get home on tuesday to start practicing. and then practice more and then when I am done with that do it all again, and then go make some money.

[CPR]

As far as the tents go check out your local sports authority, 2 weeks ago I saw an ad in their flyer for quick shade tents for 69.00.

[Mark]

CPR

I called the local Sports Authority store. They have them available. When I get back home next week I will pick one up. Thanks,

Mark