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Q & A Monday – March 25, 2013

Jodi McRaney RushoThe great thing about Q & A Monday is I have to do it on MONDAY.  If it were just called Q & A then I would put it off and we would never get to the questions and answers!  These questions are from readers and the answers that I sent back to them.  They are offered here as an informational resource, and maybe, if you have a question of your own, you’ll be inspired to ask (don’t be shy).  I’ve removed personal details for privacy, if you asked a question and want attribution and a back link, let me know.

  • Q:  I have a kiln that I have been playing and experimenting with for months now.  I adore wine bottle glass, and have had complications casting melted wine bottle frit that I make.  From research I have done, and some of my experimenting, I have found that wine bottle glass is difficult to cast unless fired at very high temps.  Even then, I have had to do a lot of cold working with the pieces I have tried to make after firing.  I love to try and make little jewelry pieces out of the frit.  Do you have any suggestions for working with wine bottle frit, including firing schedules at all?  Thank you so much!
  • A:  Frit is a little complicated.  The smaller the pieces, the more heat is required, so yes, they do require high temperatures.  Then, ad in small jewelry molds, which are a small volume of glass and it gets even more tricky.That being said, the easiest thing is to use small ~1/4″ frit pieces and try this firing schedule:

    300/hr to 1100 hold 10 (this stop makes sure your mold and glass are all the same temperature) 300/hr to 1650 hold 20
    9999 to 1020 hold 10 (annealing stop)
    200/hr to 750 then off

    The annealing is probably conservative, and with jewelry pieces, a natural cooling cycle is probably annealing enough, but I’m kinda careful about that stuff.  This is the schedule I use when I’m making panels with wine bottle frit, or using jewelry molds.  I do still have to cold work, but I usually do that on a tile saw or grinder and then fire polish the pieces.

    What we are doing here is heating the frit chunks slowly enough and holding at a temperature where they will melt, but not so high that they devitrification process is accelerated.

    If you are using smaller (like sugar) frit, then the process is more similar to pate de verre.

    I will try and do some more conclusive testing my self, particularly as this is a question I’ve also been working on for a long time, it would be good to get it nailed down.  Can you let me know how this works out for you?  Photo’s would be great, then I can help with further suggestions.  Don’t give up!  We can figure it out, it just takes time.

 

  • Q:  I don’t know if you covered this already or not but do you flatten a bottle first and then slump it in the mold?  Or can you just put the whole bottle on a mold and let it flatten and slump at the same time?  I have an Evenheat Set Pro kiln that I use for glass fusing and goes up to 1650 degrees F.  Thanks in advance for your answer.
  • A:  I have only flattened the bottle first and then put it in a mold, except when I’m using texture tiles, then I flatten the bottle right onto the tile.  It seems like it should work, I’m just wondering about how the bottle will fold down into the mold, if it will gob up or not.I have a fusing batch going in tomorrow, AND a handy bottle dish mold, I’ll give it a try and let you know what happens.  …And, here’s what happened:

bottle before firingBottle on the mold, fired with a slump firing schedule.

Here’s the bottle after:

Bottle fired directly in slumping moldYou can see that it did gloop down a bit.  The glass also dragged some kilnwash off the side of the mold.  Here it is out of the mold:

Flat slumped bottle

  • Q: I am sure you are busy, but I wanted to find out if you received my message and question. I was wondering how you get your lines so straight in the you glass etching pieces as shown on your “Creating Texture – Carving” page. I am just getting into etching and can’t images lines that straight!
  • A:   Yep, I did see it, been working my way down the e-mails this morning.  It helps me to draw a line either on the glass or on the back of the glass where I want the engraved line to be.  I use a flex shaft with my dremel, so that helps with the hand fatigue thing.  I use a water feed made of tiny surgical tubing and…I practiced a LOT.  You could try clamping a straight edge on your glass (I’d actually shim it up a bit so the shaft of your diamond tool touches it rather than the diamond part) and engrave along that.  I’ll add that to the list of tutorials, it could be quite interesting to figure out. Also, I’ve noticed that holding my diamond bit at an angle as I carve reduces the tendency for spin out.  I’m working on a whole new set of pieces that are carved, I’ll be interested to see what you think of them. Good luck and give the practicing on some scrap a try, you’ll get the hang of it quickly!