Worried about Drilling

[CrackFixKY]

Well I have been practicing a lot on my practice glass but have never had to drill one yet. I am really worried about drilling because everything I have read doesnt really go in depth about drilling. My main question is how do I know that I have drilled down deep enough? Is there any tips to making sure you are not going to hit he laminate?

Travis

[screenman]

The outer layer of glass on most UK cars is about 2.2 mill this gives you an idea of how far you can go about half of that should produce a bullseye if you are popping a star or a crack.

I know I am going to repeat myself but try and leave your bad work on the practise screen.

[daris]

CrackFixKy

You drill depending on what they taught you. Do you know Why you are drilling. Or do you just dril because you have a drill and that's what it's used for. I drill to open passage ways for the resin to flow in. Do you use drill lubricant? Once the lubricant starts to fill your chip, you have opened the passage ways and you stop. I set my shade as to do a repair, and put 1 drop of resin on my break and if it's accepting resin I do the repair, you can usually see your chip start to fill right away.

[mrchip]

using drillto clean out pit is always a good thing to do..if you are drilling deeper you can see the black disapear..that means you have gone far enough..also you can hear a definite change in drilling sound when you get to close to the laminate..practice because there comes a time when you have to drill

[screenman]

Mr Chip please explain (when you drill deeper you see the black disappear). On some small chips this may happen by the heat from the drill causing the glass to expand therefore shutting the chip up.

The black is air why does drilling, other than what I have mentioned above make it disappear???
I agree with the change in sound this is due to the abrasion taken place within a confined area ( the drill hole) being muffled very slightlyby the surrounding glass. As opposed to when you first start to drill when there is nothing around the drill head to soften the noise.

[Mr Bill]

This is how I determine drilling depth.
At home, take an old piece of scrap windshield and hold your drill bit across the side edge of the windshield. Now you know how thick the glass is .
Next cut a sliver of blue masking tape 1/10inch wide and 1/2 inch long and pinch it around the drill bit, so that it marks the thickness if the glass on the drill bit. Pinch the tape around the drill bit so that it looks like a little flag. Then trim the flag so it is about 1/10 inch long.
When it comes time to drill the windshield, just drill half way up to the masking tape on the drill bit and you will have drilled 1/2 way thru the windshield.

[screenman]

Daris, our bits do not use any lubricants do you mean that you use a small amount of resin to lube the drill as some do. We find if there is any resin in the pit it makes the drill much less effective. I much prefer the drill for cleaning dirty pits etc. to the scribe but that is my personal opinion.

[mrchip]

screenman...to clarify ...on a slit crack where it shows black from outside will go away when you break thru to crack ..i wasn"t refering to a bullseye..sorry to confuse you

[StarQuest]

daris,

Not to be critical but your used procedure for drilling is not widely accepted.

Not sure who taught you that but it's not the proper method!

[screenman]

mrchip, seeing as the black is air where does it go when you break through to it. The only thing that would make it appear to disappear is the heat caused by the drill expanding the glass and closing the damage. I am still confused but then again that is not unusual for me.