I 've fused some larger irrids perfectly, but have ruined them slumping in Bullseye molds. The first , a round piece seemed to go down the sides first and ended up with a slight dimple at the very bottom. On reslumping, even though I had drilled another hole, the bubble grew. The second piece was slumped into a square slumper . This time I ended up with bubbles trapped 1/2 way up the sides on 2 corner sides. I had asked Bullseye for irrid slumping tips after the first fiasco but they did bot work. Anyone have tips for fusing and slumping irrids through their trials and errors??
Nope, just slow down a touch, reduce you ramp a bit and lower the top end temp. I will add a qualifier in saying that it has worked for me in the past.
Give me an idea of your firing schedule now, maybe we can tweak it together, and what kiln are you using? Does make a difference. I had a little Paragon that was already slow enough, but when I fired the same thing in a faster, larger kiln I had to go quicker to get a good bend. So give more info...
The second time around I did this - 400 degrees per hour to 1180, hold for 10 to 20 minutes, then cool as fast as possible to 960, hold for 30 minutes, then 100 degrees per hour to 700, hold 1 minute, and then cool to room temperature. This is the schedule Bullseye recommended after my first failure. I use a 28" Jenken kiln.
Possible solutions to these and other interesting predicaments may be found at the bottom of the page!!
Hmm... 1/4 in when it goes in, leaves a bubble in "corner on the rounded mold"? Your schedule is certainly slow, so let's try faster, by the way, I am in agreement with
Connie, but with a qualifier of "it depends which Irid it is, the lighter colors seem to act stiffer, but they do in general, but the darker colors, black, dark amber , dark purple, seem to bend easier and are generally softer, or perhaps the term would be "heat absorbent"?
And Michele, Bullseyes irids are designed for fusing and do not burn off, at least they haven't for me, on Full fuse which is much higher than bending temp.
Will, try this schedule, which worked for me last week on some deep plates, but my mold was different, but it should make no difference on results, assuming a diameter of 15" app. by 1/4" thick glass, properly annealed.
from 300deg F per hour ramp to 750deg F, then 1200degF/hr ramp to 1260degF, check the bend. Peek by lifting lid briefly, careful of the eyes, to see if it is correctly bent, if by some chance it is not, leave the kiln to soak here for 10 min and check again. I use ceramic molds and stainless molds and have had no problem with any. When I have checked and all is correct, I shut off the kiln and leave it alone,. With 1/4" glass I do not crash cool, nor do I fire down. I use a 23" Evenheat, which is a brick kiln like your JenKen. Try it an let me know.
I am still wondering if I should drill more holes just in case. I used a square ceramic slumper - not really a mold with corners. Midway up the sides towards 2 corners it seemed to wave and have a broad bubble.
When I did a shallow 17" round, the dimple or small bubble was in the base.
This is getting really expensive when I ruin it. One of the Bullseye Irrids I used is $38 a Sq. Ft in Canada, so the glass one of the pieces was almost $160 OUCH! I thought the hard part would be the fusing.
BTW I am Marim - not Will. Willmore is hybrid of my last name.
Another thing you might want to check is if your holes aren't plugged with kiln wash, and some of those molds have a nice lip on the bottom, but the air has no outlet when it's sitting directly on a shelf so instead of getting squeezed out it's getting jammed up. You might try setting the mold on some short kiln furniture. Obvious I know, but........
I'm in Ottawa - about 7 hours from London or Sarnia. Yes, I know I'm getting ripped off. Glass fusing is relatively new here in Canada so the prices are truly outrageous and you have to wait weeks for some colours. I waited 2 1/2 months for a Bullseye Granite. I have ordered a great deal from the States and had it shipped up, and even paying $65 upwards US for shipping I am still far ahead. I paid $133 US for a bucket of frit plus $50 shipping. It was $380 Cdn here.
I think I will try your schedule and drill 2 more holes opposite the others.( I hope I don't break my mold! ) I will let you know how it turns out.
InspirePoint website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.