When the repair fails

[screenman]

KEEP IT UP!!! How many times I have to say this to guys I have in for training, be they newbies or old techs looking for improvement. In other words make sure when drilling into the screen the drill is facing slightly downwards, most guys have a tendency to drill upwards without realising it. Also do not allow the bur to get hot, lots of small bursts on the drill allowing to cool between bursts. Get this bit right and your drilled repairs will look better.

[jayjacque]

For the OP. I woulldn't hesitate to work on a bullseye that's been there for over 2 years. I think sometimes they are there for years. But of course that could make it harder to fill if it's got contamination. "Could", not necessarily "will".

And the question whether there is more chance of break-out if drilling or flexing. I think no, not if the tech is watching what he is doing. The other day I had one that looked so normal. I did no drilling, set the bridge with the injector properly placed over with very little pressure. And as soon as I let the injector down it started to run - over 1" one direction and almost that far another direction. Really weird. If I hadn't been watching close and backed off I think it would have kept running. And I didn't back off that much because I didn't have much pressure on it to begin with. Sometimes there isn't much explaination. When that happened I moved the bridge over and drilled and popped a bulleye, then it was able to fill.

One thing about it is when they just start to run a little bit, it's kind of like a fresh break and even though it is grown larger, they usually will fill (even if you have to end up using a little heat). At least that's what I have found.

[Sneck]

Yesterday I was inspecting a combo break for moisture by pressing with my probe on the break at various points around the body of the chip and watching very closely for the presence of moisture and "hidden" damage. As I was pressing with my probe, the break would open up a little and reveal a couple "hidden" cracks about 1" long each that I did not know were there. I call them "hidden" cracks because when I release probe pressure the cracks completely dissappear. I would not have known about these hidden cracks if I had not taken the time and inspected the repair properly.

Had I not known that the hidden cracks were there, I would not have known that that they needed to be filled. So I took extra time and probing throughout the repair process to make sure that resin advanced throughout each crack.

By the way, one of the legs was not holding resin because it was sucking air at the surface of the glass. I "curred" this problem (no pun intended) by placing a bead of pit filler along the small crack and covering it with a curring tab. This trick is nothing new of course, but it's something for the newbies to remember. I then Flexed the leg and watched the resin from the repair process advance and fill this stubborn leg.

Sometimes you gotta just slow down, take a good look at the "entire" break, think about the problem, and then solve it with the tools and knowledge you have.

So be sure and perform a good pre-inspection of each repair before you even think about putting your bridge and injector on the glass.

[rowdy13]

Yesterday I was inspecting a combo break for moisture by pressing with my probe on the break at various points around the body of the chip and watching very closely for the presence of moisture and "hidden" damage. As I was pressing with my probe, the break would open up a little and reveal a couple "hidden" cracks about 1" long each that I did not know were there. I call them "hidden" cracks because when I release probe pressure the cracks completely dissappear. I would not have known about these hidden cracks if I had not taken the time and inspected the repair properly.

Had I not known that the hidden cracks were there, I would not have known that that they needed to be filled. So I took extra time and probing throughout the repair process to make sure that resin advanced throughout each crack.

By the way, one of the legs was not holding resin because it was sucking air at the surface of the glass. I "curred" this problem (no pun intended) by placing a bead of pit filler along the small crack and covering it with a curring tab. This trick is nothing new of course, but it's something for the newbies to remember. I then Flexed the leg and watched the resin from the repair process advance and fill this stubborn leg.

Sometimes you gotta just slow down, take a good look at the "entire" break, think about the problem, and then solve it with the tools and knowledge you have.

So be sure and perform a good pre-inspection of each repair before you even think about putting your bridge and injector on the glass.

Sneck, I appreciate your response and I'm learning a lot from you guys. You talked about resin running out of a crack when you are working on it. Here's what keeps happening to me, and let me know if it's the same thing you are talking about. I have a GT system, and the first think I do is do a vacuum cycle for about 2 minutes, then I introduce the resin and do a pressure cycle. After about 30 seconds, resin will start coming out of one or more of the cracks. When you apply pit resin to the crack thats leaking resin, is this in a pressure cycle or vacuum cycle, or are you having no pressure or vacuum when applying the pit resin and tape, and then starting over? when you apply the pit resin and tape to the "leaky crack", are you curing it?

[Sneck]

rowdy13, I am not familiar with the GT system. I use both Delta and Liquid Resins equipment. So keeping that in mind, here is what I do...

When you apply pit resin to the crack thats leaking resin, is this in a pressure cycle or vacuum cycle?

I put the pit filler and cure tab on the leaking crack while in the pressure cycle. It may or may not make any difference if you plan on performing several pressure and vacuum cycles to work the air out of the break.

When you apply the pit resin and tape to the "leaky crack", are you curing it?

Since the leaky crack is now "capped" meaning no air can go in or out because it is covered by pit filler and curring film, I don't cure it until I cure the entire break at the end of my repair process. This also ensures that I still would have the ability to flex the leg with my probe even if it is capped in a "liquid" state (pre-curred state).

Other techs may have similar or different methods, but this has worked great for me.

I hope this helps.

[screenman]

When you have surface leg it is a good idea to flex from behind the screen as this will open it up, flexing from outside will often close it.Certainly I agree with most other things said. Why do you need to pull a vacuum for 2 minutes before placing resin in, surely a vacuum is a vacuum be it for 2 seconds or 20 minutes, if resin was in I could see the reason to give the air time to flow back through resin but not when empty. I have asked this question before from users of your equipment but as yet have not heard an answer, apart from I was told too. Please enlighten me.

[gt_repair]

Rowdy
As I stated before, I use the spectrum. you do not really need to have the vac for 2 min., I pull one for maybe 15 - 20 sec. Then turn to fill for 5 10 sec., inject using just enough pressure to get the spring type action. I will lock down the pressure about 1/2" past the point when it gets springy. I hope you get what I am saying... I will pull one more vac cycle for maybe one min. then back to pressure. Most times that is all it needs. Time will get you the feel of it.

Ask Brent for my Phone or PM me with or for a phone number now that you have the posts allowed to PM. and I can tell you better... Did you get a DVD with you system?