Bullseye explained.

[screenman]

If you can imagine a bullseye is a cone shaped piece of glass pushed back from the surface of the windshield. Now imagine also a cone shaped ice cream that you wanted to cover in your favorite sauce or syrup, now would you poke your finger in the top of the ice cream to get the syrup to run over the sides, no I thought not.

I am open to questions and yes I have seen the bullseye that exists without an impact point showing at all, extremely rare and you would need to drill and pop on the outside of the damage or in other words the circumference, this to make sure you are not just sticking your finger in the middle as I pointed out earlier.

[Nomad]

I use the drill a lot to clean the loose glass and debris out of the center of the impact point. Like a rotary scribe, I think is the way screenman described it in past posts. Sometimes I also just "nick" the edge of the impact point where the cone of glass rests against it to create a path for the resin. I don't think this helps very often but I used to run into a bulls eye every now and then that was so tight against the surface glass that is was hard to get the resin to go in. This seems to have solved this problem. Again, I just nick the edge by holding the drill at an angle and removing a little glass from the edge of the impact point. I do not drill a hole.

[sunshine wr]

not to any scale

[puka pau]

sunshine wr;

That's an informative graphic depiction of a bullseye break in an elevation view. It should be obvious to all that drilling the center of the cone will reward the technician with additonal drilling practice and nothing more. Now, truth be told, I have on occasion drilled into the "channel" between the cone and the outer lite but this practice is a gamble. Sometimes it works, sometimes not. You really have to size up the situation and recall past experiences with this technique to pre-judge the odds of success. I've had much more consistent success drilling at the perimeter or "circumference" of the damage or as in a previous post, drilling into whatever void presents. It really is a case-by-case scenario. They're all the same but they're all different. The more you repair hopefully the more fluent you will become in assessing appropriate technique.

Cheers;

Puka Pau

[screenman]

Thank you for putting the diagram up, your computer skill far exceed mine. Nomad, that is my method as well I without the nick to the edge bit though. I find most often if a bullseye is not filling then I have too much injector pressure on the seal causing the break to close up, imagine putting pressure on the glass either side of the pit and you will understand what I mean.

Hopefully if this post helps one person understand why not to drill a bullseye then it is worth out time writing.

[Nomad]

I have also put a probe down the injector through the resin to press the cone down into the laminate a little, to make room for resin if having a problem with filling a void somewhere around the bulls eye. Once in a while, not often, I will use heat from a mini torch on the outside if I am having this problem and that seems to help a lot. Let it cool off completely before curing if you do this.

[kingmonkey]

I really appreciate this post. I try to drill as little as possible but this really explains a lot about them. Thanks for the info guys!

[Brent Deines]

I gotta tell ya, I'm very surprised at the number of windshield repair technicians who find it necessary to drill a bullseye. The only time I drill a bullseye is when there is no damage to the surface from which to access the damage, which in my experience is rare but does happen.

When repairing a bullseye with no surface damage, I drill directly into the center of the bullseye. Doing so will open an airway to fill the break. Using the illustration provided you can see that drilling the surface glass in the center of the damage will create an opening all the way around the cone. The opening around the top of the cone is not affected by the depth of the hole, but I prefer not to drill deeper than necessary to access the air space for cosmetic reasons. You can drill off center but you will just have to drill deeper as you can see from the diagram.

[puka pau]

It's my recollection that this thread expands on the "How would YOU fix this" thread. That thread was initiated as a question about repairing previously repaired damage. I reread my post on this thread and perhaps I wasn't perfectly clear about my position on drilling bullseyes. So to clarify, I don't drill bullseyes unless I'm attempting to re-repair previously repaired damage ( unless, as Brent stated, there is no discerible impact point or pit). And after having attempted to repair at least a few dozen (if not a few hundred) previously repaired bullseyes over the years I've found that depending on the quality of the initial repair there are several techniques that often can be employed with somewhat satisfactory results - and I stress the word 'somewhat'. The re-repair in my experience will rarely if ever equal the cosmetic quality of a repair that has been performed competently the first time, but most of the re-repairs I've accomplished do look significantly better than the original.

Cheers;

Puka Pau

[honey123]

Well, personally, I have not felt there is a need to drill a bull’s-eye in the first place! And even if I do, I always make sure that the surface I am drilling does not get damaged due to the drilling. Anyway, those of you who want to repair a bull’s eye should make sure to drill right in the center of the bull’s-eye!
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