Tips needed to stop cracks spreading

[The Defpom]

Hi All,
I am new to WSR, I recently purchased a selection of Delta Kits equipment.

I got a windscreen (windshield) from a friend who is a car wrecker, I have been doing a bit of practice and so far I seem to be getting the hang of it OK, I have a couple of things that I require some guidence on

The first things are cracks that are growing, I created some damage by drilling a hole and hitting my probe inside the hole, which created a really good combination break, a nice one to have a go at, I filled the impact point and some of the crack, the crack was below the surface of the glass, so i could only fill it from the injector, it was filling slowly, so I tried gently pressing the glass with my finger to open the crack a little, then the crack began to grow.....

I tried drilling a hole about 5mm from the end of the crack and popping it with a probe to create a mini bullseye to stop it spreading, I thought it worked, until it started to continue on its way, so I then tried drilling a larger hole right down to the laminate at about 5mm from the end of the crack, again, it jumped to the hole, and all seemed well, but then it carried on again... how can I stop a crack spreading, what methods do people tend to use with the most success ?

I know that sometimes you just cant stop it from happening, this is just a practice glass, but i would like to get the hang of this before I venture onto peoples vehicles...

The next problem i am trying to learn the best way of fixing is dirt inside a break, mainly bullseyes and cracks, does anyone have a preferred method of cleaning the break of dirt/glass particles ?

I tried to repair a bullseye/combination on my parents car, it had been there for a few months, at the time I didnt try to clean it as I thought it looked OK, but once I had filled it the dirts was very obvious , I ended up drilling out the repair to remove the dirt laden cured resin, which looked better, but I am still not happy with it..any tips to help resolve dirt inside breaks would be appreciated, but to prevent the problem then having to fix it afterwards !

I also have a break on my cars windscreen, I had it repaired but I think they messed up, as it damage was worse when I got it back to when i took it in , it just had a small combination break, when I got it back half the bullseye was only half filled and it had cracked about 1 inch to each side of the original break, I tried flexing the glass and the crack is not moving, whilst i was waiting for the repair to be done I heard other customers complaining about problems too...looks like I chose the wrong place to go to !

now because they have done a repair I am cant seem to fill the cracks, my guess it that there is resin on the surface which is preventing me from just injection straight in, I ma not keen to drill it yet, not until I get more experience anyway as the car is less than 1 year old and I don't want to end up with a poorer quality replacement windscreen instead of the factory one.

A good thing to come from this is it motivated me enough to decide to learn how to do it myself, just need practice...

Phew...this has turned into being a pretty long message... still, it is my first post here.

[DaveC]

Scott,

This is why one practices;)

Firstly, do not assume that any damage is limited to what can be seen by the naked eye. Try using a magnifying glass and really examine the area for hidden damage.

As well, any time you you add additional pressure/force to a damaged area, you run the risk of making things worse (before making them better;) As you continue to practice, you will begin to get a feel for certain things like how tightly you really need to torque down your inector to maintain an adequate seal, how much pressure you can apply with your probe/thumb, etc. . . Be especially careful when dealing with damages near the edges of the windshield!!!

As for dirt in the damaged area, different folks have different opinions as to whether or not these areas can/should be effectively cleaned. My general rule of thumb is that I will not attempt a repair on a crack that is more than a week old. As for combos, bullseyes, stars, double-helixes, etc.... that are older and dirty, I am very honest with my customer and advise that while I should be able to restore structural integrity (in many cases), the actual repair may still look very obvious. I leave it up to the customer, either pay me $50.00 bucks or pay for a new windshield;)