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Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 9:16 am
by Mr Bill
What steps can be taken to minimize crackout of an unstable windshield during the repair process?

Re: Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 10:29 am
by screenman
Only had it happen twice that put it beyond , take it easy, keep it cool and do not use too much pressure. Why do you ask are you having problems?

Re: Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 10:46 am
by Clarity Glass
If a chip looks unstable I will drill the tip and pop it. Secondly when using heat I will have the heat synch(sp?) close by. I let my customers know when a chip looks unstable so we have no surprises. If it cracks they've been forewarned, if it doesn't your a hero.

Re: Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 11:26 am
by Mr Bill
The customer said it had the chip had been growing. It had a small inpact point and three cracks each about 1/2 inch coming out of it like a mercedes benz emblem.. I dried it with the drystar and it closed up. Waited till it cooled and applied injector. I did not have a lot of injecor pressure applied. Within minutes, the cracks had grown to 1 1/2 inches. The resin would not wick further along the cracks than 3/4 inch. Vacuum/pressure cycles made the cracks longer so I exposed the repair to sunlight and after it cured, I went to the end of each crack and drilled and popped, so that I was now injecting from the ends of the cracks. I was able to fill it ok that way.
I had a feeling that the glass was unstable before I began the repair, and was going to tell the customer, but she dissappeared into her house before I could warn her.
I gave her a free repair. and she asked me for some business cards.

Re: Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 1:57 pm
by screenman
I suggest you had way to much pressure somewhere, were you working outside? did you use a UV shield? Resin will always flow easily into a new break. Sounds to me like a super simple star break, you sure did something wrong somewhere.

Please give us more information or at least answer my questions so that we can help you more.

Re: Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 2:42 pm
by Mr Bill
I was working outside in sunshine I used a UV dome. Very little injector pressure. 1/2 turn on injector; 3/4 turn on legs.
Could the suction cup on the injector stress the glass?

Re: Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 2:51 pm
by screenman
Very unlikely, how hot was the windshield? if it is too hot to put your hand on then it is too hot too work on. Each time damage has run on me it was because I did something wrong, the glass was too hot, I had too much pressure on the bridge, I flexed the legs without concentrating or watching exactly what happened when I did so.

Has anyone ever done a test with UV dome to see if you suffer from indirect UV with it. I do like the look of the dome and what it can do but I have never tried one.

Re: Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 5:09 pm
by sunshine wr
When I have a "tight star" (3 or more legs) or a "Batwing" I will drill and tap at the impact point to relax the break.

Re: Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 5:15 pm
by Mr Bill
The glass was not hot. there was a cool breeze blowing.
Unlikely or not; it happened.
Sometimes people get chips and the windshield cracks out within 20 minutes without anyone touching it. Who is at fault there?
I have done enough repairs to be conscious of when I do something wrong during the repair.

Re: Unstable windshield crackout during repair.

Posted: March 3rd, 2011, 11:03 pm
by Clarity Glass
what sunshine said. Also gentle probing of legs adding pressure if needed. Resin stopping 3/4 on all legs is weird. Was the leg solid from impact to tip..no fracture along leg? I feel your frustration. We want them all to turn out perfect but perfect repairs all the time is not going to happen.