Bullseye with needle.. Sharp or Blunt?

[screenman]

I hope my last post did not sound to harsh, it was offered up as advice for future success in our great trade.

[impala-renegade]

I hope my last post did not sound to harsh.

No worries S-Man, I am used to seeing your posts and they are usually kinda craggely old man posts!

[screenman]

There might well be a reason why my posts look like that and you might well have guessed correctly.

Thing is 4 years ago I stopped going out to garages when called to look at damaged glass as 9 out of 10 had been badly done before.

[bill lambeth]

This board has really become a joke ! This topic has got way of course as Brent would say !

[impala-renegade]

Whatever, people lose permission to post for starting too many topics so this is fine with me.

[screenman]

Please accept my apologies Bill, the old brain is not as sharp as it once was and the conversation wondered a bit. Consider my wrist well slapped.

Feel free to bring it back on topic for us.

[bill lambeth]

I have never been a fan of popping a bullseye doing more damage is never a good thing. That said the end of a crack is not a bad place to put one. But using the bullseye often enough that you actualy carry a tool to make one? Sounds like lazyiness to me? Never popped one except fro a crak in over 50,000 breaks

Not sure what you are trying to say ! I do pop most batwings depending on their location in the w/s. Not going to get into a pissing match with you !

[Brent Deines]

Whatever, people lose permission to post for starting too many topics so this is fine with me.

That's news to me!

Thanks for the reminder to bring the thread back on topic Bill. I was gone last week and still trying to get caught up.

I'm with GlassStarz on popping bullseyes. I only do it at the end of long cracks...just don't find the need any other time. Just my personal experience, not trying to start an argument.

Using a properly sharpened instrument that is correctly matched to the hole size is extremely important to getting consistent results when popping a mini bullseye. In our testing too small or too sharp of a point will cause small fractures in or around the drill hole. Too large of a point will chip the glass at the top edge of the drill hole and too blunt of a tip will crush the glass at the bottom of the hole. Also the shape of the bur and the method used to drill the hole affect consistency. We've found hardened steel works better than either carbide or soft steel. Can't give you a scientific explanation as to why the hardened steel works better than carbide but in hours and hours of testing that does seem to be the case. Not saying a filed down carbide bur won't do the job, just that in my experience the hardened steel works better. We experimented with a dozen or so burs, and a dozen or so point shapes, sizes and types of metal used to make the point. In the slide hammer you can compensate for the type of metal in some cases but with the spring hammer everything is calibrated to the spring tension so I don't recommend using anything but the points that are made specifically for the tool.