Another Long Crack Question

[AGSS]

Just curious,

Is there certain long cracks that most of you will not repair?

For example. A 'stress crack' A crack comming from the edge of the glass with no point of impact. I have read on this forum that some tech's have a problem with long cracks re-appearing or running out. It seems to me that a long crack resulting from stress from the windshield would flex too much and break loose the resin. If there is enough stress from the pinchweld to crack the windshield, there would certainly be enough stress to break the resin and open back the break..?

Any thoughts?

[Coitster]

Sure stress cracks can be repaired. My recommendation is when you come across a stress crack pop a bullseye in the crack as close to the edge as you can. This helps to relieve some of the pressure but you must also inject an extremely thick resin into the edge. This is where most cracks break apart.

In regards to another post I made on Long Crack Repair and resins and what should be used and what shouldn't. Most chip or crack resins won't break apart near the point of the crack, however the closer you get to the edge of the crack is where all the massive stresses come into play. So for example let

[AGSS]

[quote="Coitster;22830"]I know I saw it, however during the curing process the resin shrunk like it

[johnnyone]

Injet a high cps into the pop, but first use a thin wetting cps then let the high cps to fill, but alway make sure it is dry before you start the procedure.

A well put procedure from a Great Crack surgen,, Thanks

[Shepard]

Popping a bullseye? I am not confident in my bullseye popping ... to often it is a star... why?

[Glasseye]

3 possibilities
* Hole depth - I normally try to drill 2/3 of the outer glass ( use the existing cracks to guage the glass thickness.
* Hole size/ impactor size - make sure the impact tool you use has a small enough diameter so it does not catch the side of the drilled hole ( I use an impactor with a flattened point)
* Impact strength - short & sharp impacts ( I use the bottom of my microlite torch)
Last but not least practise, practise, practise.

[Sneck]

Shepard, I was trained to use a sewing needle. I think it's called a #10 or #11 sewing needle. I drill down to a depth that is 1/2 of the length of the burr (cutting edge) on my carbide drill bit. Insert the neede and strike it with a tappet (which is just a piece of plastic used like a light-weight hammer).

If the mini-bull does not form after two strikes, I drill a little deeper - but only a tiny bit, then try again. After you achieve a mini-bull using your equipment, you will find the procedure to be easy, consistent, and reliable.

Sneck

[Mr Bill]

Shepard
It looks to me that you are not drilling deep enough and then striking the scribe (or whatever point you are using) too hard
You only need a light tap if you are at the proper depth.

[wilz]

Coitster,

This is true, very true, however if there is any presence of things like road grim, rain-x or any glass cleaner or residues it makes your repair very difficult

Have you had any sucess in removing any of the above from cracks?

[Coitster]

Yes I have.