when you repair long cracks should they be visible?

[specialeffects]

thanx for all d advice , i really appreciate it, and yes i;m new to this so plz excuse me, you guys really helping me out tho thanx again

[chipfix]

I use the wicking method as described by Brent but instead of holding the bottle or eye dropper to the crack I put a drop on the end of a piece of pipe cleaner (the tobacco type of pipe).
I use white color cleaners to be sure it doesn't stain the resin and cut them into 2''-3'' pieces.
The fibers if the pipe cleaner holds the resin in place by surface tension,this eliminates waste and one drop can go a long way.

Edit:
Yay,we can edit our posts now!

[screenman]

My method is the same as Brents, the only exception I may make depending on the crack is to drill/pop/stop and then drill 1/2 in from that point and fill from there. This speeds the process up on some cracks as the end inch or so can be very tight, think of it like a river that starts thin and end up very wide it would take a long time for the thin part of the river to fill the wide part. Just my way of course and may not be the right way, but it sure earns some money very quickly.

[just chippen away]

I use the wicking method as described by Brent but instead of holding the bottle or eye dropper to the crack I put a drop on the end of a piece of pipe cleaner (the tobacco type of pipe).
I use white color cleaners to be sure it doesn't stain the resin and cut them into 2''-3'' pieces.
The fibers if the pipe cleaner holds the resin in place by surface tension,this eliminates waste and one drop can go a long way.!

I use Q tips to wick the cracks.

[cracksinlagos]

I lately found out that long cracks are easier to repair. I do a lot of long crack repairs because car owners in this part of the world (Nigeria) neglet small Bull's eye or stone chips And these migrate to longcracks over time. I use the rasins in plastic bottles for this purpose. If the crack is accessible, I flex from the inside with my thumb starting from the inpact point to the tip. This is because the crack opens from the base to the tip( This explains why the crack expands out because the the push is from the base.) If you can't flex from the inside your self, use the crack expander or seek human assistance.

PROCEEDURE
As I flex the windshield from the inside to open up the crack, I simultaneously run the tip of the plastic bottle containing the rasin directly on the crack in the same position as my finger or thumb and gradually fill the entire length and a curing tape is placed on the length and is cured with a UV light. The result comes out great. Try this method, it works and is still working for me and I believe it will work for you. Simple!

[chip-away]

Being very new in this field I am glad to have found this site to read all the insightful, helpful instructions from the experienced guys. I just received my third 'practice' windshield to begin working on nothing else but cracks. I have the 'chips' bullseyes, stars etc down very well. But the cracks, well they are a different animal all together. This particular subject has been most helpful and you veterans have no idea how helpful you are. I'm glad to see this as it shows the pride you guys have in this craft. Kudo's!

[chip-away]

Question: Once the curing tape is placed over the crack as you work down the crack, the tape should stay in place or you risk getting air in the crack? I was working on a test Windshield and the crack was filling just fine, as I was looking at the the crack my hand slide down moving the curing tape off of the crack. I put it back in place but I noticed some black spots in the crack. Was this air being introduced into the crack? I was very happy with my progress until this.

[Nomad]

Probably some air got in there. If you had your hand on the glass you may have put pressure on it and flexed it. Flexing in and out with pressure from pushing on the glass from inside or outside will almost always introduce air. This is one reason people use crack expanders because the pressure that is put on the glass is steady and doesn't vary. The same thing can happen with sliding bridges. The stem of the injector is pressing on the glass and when the pressure is released the glass can rebound and suck air into the crack. If you want to try something different, lube the glass (I use hand lotion) so the injector can slide, also mount a suction cup that can also slide next to or opposite the injector. As you are injecting along the crack you can be pulling up on the cup flexing the crack open. When done move the injector completely out of the way and very slowly release the pull on the cup so the crack closes gently. If done correctly the crack will be completely filled. If not then pull again and chase the air out with the injector using the same technique as above. I have used this quite often on tight cracks, use a 2 inch diameter cup at least. I use the red flip lever plastic ones from harbor freight I think are 2 1/2 inch.

[screenman]

I used to use the sliding bridge method now I only use a Qtip. one thing I always do is wet the top of the crack with either Magnibond or Pit Fill before I place the tape along it, that way if the break does open again slightly the only thing above it is more resin.

Hold both your hands in front of you about 2 inches a part finger pointing upwards and palms facing each other, and imagine this to be the crack, now move your finger tips slightly together this is what happens when an injector is placed upon the crack with enough pressure to create a seal, move your finger tips apart again and this would replicate the injector being removed, something has to fill that extra space.

I hope that complicated explanation helps you understand the mechanics of what is happening.

[chip-away]

Appreciate the response, thanks.