Finding a crack on completion

[glassman52]

I have sorta rushed a bit to complete several small projects for a show only to find one or more cracks in them when competed causing me to repair them after finishing them. I am careful with the heat and do not stress the glass in any way and seemingly only had this problem with "new" glass that I have purchased recently. Can't recall ever having that happen in the past and was curious if anyone else has had that recently happen?   
 

[Tre V]

Oh what a shame! Is it glass made in USA?

[glassman52]

Yes I believe so as far as I can tell. I buy from shops here in Maryland and they are pretty reputable but I have a lot of different glass and do not know exactly where it came from.

[Stephen Richard]

From what you tell us it is difficult to be helpful.  Copper foil? fusing/slumping? what kind of shapes?  etc.

[glassman52]

Foil, I'm working on pics. to show as I still have two of the pieces that were repaired. They were all "small" projects as well.

[Rebecca]

Be sure that your glass doesn't fit too tightly.  There should be space between glass.  No space is a crack waiting to happen.

Rebecca

[glassman52]

 I've never had this happen before, if it was just one incident I would say "oops" but it has been a few and I'm doing nothing different. (to my knowledge)

[Rebecca]

Are you doing "harder" to cut pieces?  Sometimes a very narrow piece of glass will show a crack after it is all finished and cleaned.  That usually means the glass piece was too narrow to start with.

Rebecca

[JoanFrances]

I've never had this happen before, if it was just one incident I would say "oops" but it has been a few and I'm doing nothing different. (to my knowledge)

Joe I swear that sometimes it is just cause it can, why it happens. 

I remember when I did my kitchen valance (a 3 piece one), it was hanging for about 6 months and out of the blue cracks were showing up that I swear were not there the day before.  I ran into about 3 projects in a row that ended up with what I thought unexplained cracks in them. 

Low and behold they were probably heat cracks that didn't happen right away, because when I finally got my soldering to look good without redoing it 6 and 10 times, I haven't had one since.  (fingers crossed)

Hope you get to the bottom of the problem because there is nothing more heartbreaking an a crack when you just completed a project.

Just curious, are you still using the same temp control device?  Could it be that it is on the way out and making the iron hotter than you are used to?
 

[glassman52]

Are you doing "harder" to cut pieces?

No not really. One was 1/2 inch and the other 3/8. I have actually cut and soldered narrower without a problem.

are you still using the same temp control device?

Yes, but a different iron and I am very careful with the temp. Just to be safe it is only hot enough not to "freeze" to the work after making contact.

The cracks have all been in "box" design patterns and were only in the first soldered panel of the assembly. Years ago I made lots of jewelry boxes and the like and don't recall ever having a crack. (and I was quite sloppy when I first started)

I wouldn't be a bit surprised if some Knock-off Import glass has made it's way into the mix.  I purchased an unusual piece of glass at Hobby Lobby but I haven't used it for anything yet. I think it might be an Import. I'm gona check it out.

[Rebecca]

I wouldn't be able to work at all with my iron that cool!

Most Hobby Lobby glass is Spectrum "T" glass or imported glass.

Rebecca

[Stephen Richard]

Imported glass is not necessarily worse than domestically produced glass.

[glassman52]

The iron I am using is 140 watt so I can regulate it pretty low and still have consistent heat.


I suspected the glass purchased to be spectrum that's why I bought it but I did see a few that were labeled China.

[Rebecca]

Imported glass is not necessarily worse than domestically produced glass.

That's true and some glass from Europe is wonderful!  On the other hand, the glass at Hobby Lobby is CHEAP and that means it is definitely not the "good stuff."

Rebecca