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fusing 2 disks as a blank to slump into mold

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fusing 2 disks as a blank to slump into mold

Postby myvalley » Thu Aug 05, 2010 5:57 pm

Hi again,

For the first time I have fused two disks into a blank to slump into a mold (opaline over tomato red, both discs the same size, will use mold 8943).

Have a couple of queries, to try and improve things for future fusings, as I intend to use this mold quite a bit.

Good part: The blank looks nice, with well rounded edges. Got champagne bubbles.
Bad parts: had some brick rain onto it (we will fix this), so had to sandblast the opaline to clean it. Also fused the blank onto fiber paper rubbed with alumina hydrate, but could see some tiny white spots after soaking the blank in vinegar and brushing vigorously, so sandblasted the back as well. Used 180 grit AO to sandblast.

My query for this blank:
Will it firepolish to a full gloss when I slump, or do I have to do a separate polishing firing?
Intended slumping schedule is:
150/hr to 500, hold 30
250/h to 1260, hold 20
Brick kiln with top elements plus side elements below the shelf (I find in my kiln this gives more even heating than using the top elements only)

Query for future blanks:
- Should I fuse on thin fire instead of fiber paper? Or directly on the kilnwashed shelf? Used the FP thinking that it might avoid any bubbles building up between the shelf and the glass.
- Would like to further reduce the champagne bubbles, this was the schedule, can I change anything?
270F/h to 1148, hold 1 hour
235F/h to 1454. Had programmed a hold of 25', but the fuse was ready when it reached 1454.

Also, would you know which colors were used on the BE sample bowls?

Many thanks for your help, it is really exciting to start using BE colored glasses on projects beyond jewelry.

Best regards, myvalley
Posts: 14
Joined: Sat Jul 24, 2010 4:15 am

Re: fusing 2 disks as a blank to slump into mold

Postby marykaynitchie » Thu Aug 12, 2010 11:46 am

Hi Myvalley,

Good job persevering on this project! After sandblasting the surface, the slump firing will make the sandblasted surface look "wetter" but it will still look sandblasted. This is actually a popular finish to projects done by Bullseye staff!

You will have to refire your "blank" flat, to a full fuse temperature to get it to look completely glossy again.

Try fusing directly on unfired (pink) shelf primer or ThinFire. I think you will have better results.

It is difficult for me to grasp your full fuse firing cycle from your description, but if the piece is already fused when you hit the process temperature, I think you need to shorten the heating up phase.

Try this cycle for your next "blank", or for your fire polish firing. ( am assuming that your piece is comprised of 2 layers of 3mm glass, no larger than about 15" in diameter.)

400 degrees per hour to 1250. Hold for 30 minutes.
600 degrees per hour to 1480. Hold for 10 minutes. At 10 minutes check the piece and extend the time if necessary.
Cool AFAP (as fast as possible, with the kiln door closed. On Paragon kilns, we program this as 9999 degrees per hour) to 900 degrees. Hold for 30 minutes
150 degrees per hour to 700 degrees. No hold time, or hold for 1 minute (either is OK)
Cool AFAP to room temperature, about 70 degrees.

You can vary this schedule to work with your own kiln, but it's a nice basic full fuse cycle for starting off.

Re the bowls in the photos we posted, the Opaline 0403 was a curious fusible version. The outsides look like Spring Green Opal 0126, Tomato Red Opal 0024, Egyptian Blue Opal 0164 and one of the yellows, possibly Canary Yellow Opal 0120.

http://www.bullseyeglass.com/products/c ... age/18166/

I hope this answers your questions. Good luck!

Mary Kay
Mary Kay Nitchie
Bullseye Glass Co.

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Re: fusing 2 disks as a blank to slump into mold

Postby myvalley » Thu Aug 12, 2010 4:15 pm

Many thanks Mary Kay for all your help. The blank is in the kiln now for fire polishing...will report as I make further progress.

Best regards, myvalley
Posts: 14
Joined: Sat Jul 24, 2010 4:15 am

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