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Those dreaded black spots

Posted: June 28th, 2007, 9:56 pm
by Mr Bill
I was looking at the latest editition of "The Wise Crack" and the Back to Basics article stated:
"Do you ever have trouble with the dreaded black dots or crescents of air left in your repairs? You would swear that you had all the air out, but after you take your injector off and cure, the bubbles are back. The most common reason for this is again, too much head pressure. The break is flexed inward due to the pressure, so when the injector is removed it snaps back, ever so slightly, to its original state, creating small areas within the break that are not completely filled. "

OK , so how do you get rid of those dreaded black spots or crescents of air after they happen?
I know how not to get them , but if you get them, how do you get rid of them?

Re: Those dreaded black spots

Posted: June 28th, 2007, 10:50 pm
by SGT
Assuming it was excessive tip pressure that caused the black spots and you have not cured, remount injector with just enough tip pressure to keep the seal and repair as normal the second time. If you have cured more than likely you will need to drill.

Re: Those dreaded black spots

Posted: June 29th, 2007, 5:46 pm
by GlassStarz
Pressure cure

Re: Those dreaded black spots

Posted: June 29th, 2007, 6:57 pm
by SGT
I agree GlassStarz. In certain scenarios I like this method as well. If you pressure cure, make sure you do not have excessive tip pressure though. You might be preloading the glass.

It would be real nice if you could cure from the inside when under pressure:)) Wish they(MFG'S) made a better universal lite that would wrap around the injector for a more focused cure.

Re: Those dreaded black spots

Posted: June 29th, 2007, 7:06 pm
by Mr Bill
Never tried a pressure cure but just for the sake of curiosity:
Assuming you pressure cure; how can you get the UV light close to the chip?

Re: Those dreaded black spots

Posted: July 1st, 2007, 1:49 pm
by wilz
You could try tilting the light at an angle so that it is facing the repaired area.

Re: Those dreaded black spots

Posted: July 1st, 2007, 4:09 pm
by Layne
I "pressure cure" by removing the shield from the repair and expose the repair to regular sunlight.

Re: Those dreaded black spots

Posted: July 1st, 2007, 4:10 pm
by Layne
Added note: I still have the injector pressure on the repair.