Trapped air in bullseye

[quietman]

Make sure that there is No moisture in the damaged area, moisture will also show up as black. You may want to put a little heat to it to help the resin flow better. You can use a small propane torch or delta kits sells a heat gun that plugs into the cigar lighter.

[screenman]

Water has much the same refraction index as glass, so it will certainly NOT! show up black.

[pommy]

Can't be water if it's happened more than once AND on a test screen (that's probably indoors) - or any other contaminant for that matter.

I've had this problem more than once and it was two different things creating the same problem.

These worked for me:

1. Cold environment, resin too thick and not filling the extremities of the break - use a thinner resin. (Or heat as previously mentioned, but risk cold/hot crack)

2. Too much pressure on the legs of the bridge caused the galss to flex - the "black" was the glass pressing against itself within the bullseye.

[screenman]

If you do use heat make sure you allow enough time for the glass to return to the ambient temperature. In testing I have found that star break legs will disappear when heated and stay closed for in excess of 60 minutes and sometime not reopen at all without flexing.

Pommy I am confused by your bit about the black being glass pressing against glass, as we know that the black is the refraction of light as it hits the air space between the glass. I am hope you will enlighten me more on your findings as I am always happy to learn more, maybe I am misreading your post if so I apologise.

[pommy]

Hi screenman

It's pretty easy to re-create, I'll take a photo and put it up

It been raining here for 8 days straight - so not much work at the moment.

Cheers,

Pommy

[t4k]

I want to see that too.

[pommy]

about one third of the damage stayed black...

It's about 1/3 - I think that is what he may be referring to? I may be wrong, but I've had this bit not "fill" many times, not as big - but when I flex the screen after moving the bridge, it went away.

It's only one option of the two I gave - maybe thinner resin too...

Cheers,

Pommy

[t4k]

about one third of the damage stayed black...

It's about 1/3 - I think that is what he may be referring to? I may be wrong, but I've had this bit not "fill" many times, not as big - but when I flex the screen after moving the bridge, it went away.

It's only one option of the two I gave - maybe thinner resin too...

Cheers,

Pommy

So, this is glass touching glass?

[pommy]

Well the resin can't get past it until I flex around it...

If I don't flex around it - cure the resin, it appears black, but there is no contaminant.

Just trying to help

[screenman]

That black is air, the damage is no where near filled. I hope nobody ever sells or even thinks about doing work for customers if that is all they can do.

Thanks for putting up the picture, it looks a good example of some of the poor repairs I see over here every day.