Boro Kiln Schedules--Newbie
 

Hey all--A friend and I are playing with boro for the first time today and we're working with tequila sunrise. There's a lot of talk of kicking up the temperature a bit to strike in the kiln. Here's what my book tells us to do for a boro program (I have a jen ken).

Temp1 = 1050
Hold 1 = 6 hours
Ra2 = Full-deg/hr
Temp = 940
Hold 2 = 30 minutes
Ra 3 = 600 deg/hr
Temp 3 = 400 degrees
Hold 3 = 0 min.

I'm hearing that with tequila sunrise to get the really nice pinks we need to crank the kiln to 1100 or even up to 1200. When do we do this? We are getting the kiln up to 1050, then working for 3-4 hours and putting our beads in as we continue to work. Is this the right way to go about it? When do we kick the temperature up to the 1100-1200 for the 45 minutes? I'm sure that sounds like a crazy question to most of you but we don't want to ruin this gorgeous glass. Thanks! Lilly and Tracy

You don't need to go to 940. Just ramp down from 1050 to room temp. If you want to kiln strike, do it at the end just before you ramp down.

When I do kiln striking (which is very rare) I hold my kiln at 1050. I actually have my kiln set to hold for 20 hours at that temp. When I'm done, I just skip ahead to the next step. The next step is to hold for another hour at 1050 to ensure larger pieces have enough time to soak. Then the next step is to ramp up to 1150 to strike for 20 minutes, then from there I ramp down to room temp at 300 degrees/hour.

300 degrees per hour from strike or soak temp to 960 is too fast for most work. Slow it down to 60 degrees per hour until you get to 960... then shut it off. No sense in wasting the time/electricity heating things below strain point... not most of our sized work anyway... and especially boro. The slower ramp from your soak temp to strain point (960) is the key to relieving stress in the piece. If you check a piece that's gone from soak to strain at 300 per hour, I'll bet you see halos under a polariscope. I did a lot of testing when I was making toys. ;)

I just did this with tequilla sunrise yesterday holding at 1050 for an hour before I ramped down - they went in clear and struck in the kiln

Another thing to remember is that kilns can be off by a lot! 40-50 degrees isn't out of the question... so if the striking temps posted don't work for you, play around with your kiln... ;)

Oh and nice job Jodie... those are pretty! :D

And I can defiitely vouch for the kiln temps to be off. Now that you mention it. My kiln runs I think 30 deg too high so maybe they were in there around 1080 :)

Jodie, I love that Tequila Sunrise!

So... one coudl do their boro work, and then, when it's at 960, do their soft glass work and ramp down from there like normal!

Yeperz and a lot of folks do. ;)