lampworking/furnace glassblowing

[laserglass]

this is my 3rd post here at LE. i have been busy with many projects, and i wanted to bring some to a finish, so i haven't posted anywhere much for a while. i have been blowing ruby red glass outside in my outdoor studio as my main indoor studio is shut down for the summer (too much heat). but in addition, i have just finished building a micro-furnace to be used with lampworking. i am just no good at gathering from solid rod without getting small bubbles. so i modified a murphy fire bucket, added a door and a crucible, and power it with a national 3a torch running off natural gas and an oxygen concentrator. i just finished a test firing, and plan to fire it up with glass for the first time on saturday morning. the internal crucible can hold 1 killogram of glass or around 2.2 pounds. the crucible is 4 inches in diameter, and 2.5 inches deep. i plan to use my bench torch (nortel major/minor combination) when adding color or working on the pattern, the dip the color into molten glass to encase. i plan to start out with marbles and large focal beads, and then branch out from there. i may have a webcam bradcast of the maiden vouyage (hopefully better than the titanic) on saturday morning. if so i will post a link to it here. i have attached a few photos to provide more details of the design. the micro-furnace is lined with frax stabilized with collodial silica. the micro-furnace is located at the back of my lampworking area leaving most of the area open for the bench torch and tools. it is mounted within 1 foot of the exit duct of my ventilation system. i plan to melt 90 coe 4C cullet in it which is compatible with all of my color.

[laserglass]

actually the one picture was taken before i finished the door. here is a picture showing the the micro-furnace hot and with the new door that i cast out of mizzou. i learned a lesson and now air the quartz tube upward that is used to guide the torch flame into the furnace. when i fired it up the 1st time, the flame came too close to the crucible and it cracked. but id didn't happen the last time i fired it up. i am adding a pyrometer to it so i know it internal temperature. i added a flow valve on my natural gas manifold so that i could set the knobs on the national torch to full open and then adjust the gas and oxygen flow remotely.

i also included a photo of my outdoor furnace/glory hole that i am using this summer. it holds about 12 to 15 pounds of glass and is fired by a propane/air venturi burner.

[laserglass]

here is an overview of the furnace, and the crucible. the crucible is actually 1/2 of a mortor and pestle that i bought at axman, a local surplus store. they have lots of them and they are cheap. so you could have a number of them, one for each color. i only plan to melt clear, no colors.

[Phoenix]

Mark- it's great to see you here- I love reading about and seeing the ideas you make come to life!

[Wonker]

too cool for words. I can't wait for you to show us some of the things you've made there. I love watching someone innovate the way you're doing. Keep it up.

[tajones1463]

This is way too cool. I will be checking back. I can't wait to hear/see the maiden voyage!

Thanks for sharing!

[Cosmo]

Looks very nice Mark. Glad to see you finally made it over here.

I've been wanting to try something like that for quite a while, but haven't had the time or, more importantly, the know-how to do it...

[laserglass]

well i had multiple failures and so the maiden vouyage went bust. i was drawing too much power from a power strip so its internal circuit breaker tripped and shut everything down. but i did not know this at the time so i was focusing on the circuit breakers in my main power panel. so between this down time plus the fact that i underestimated how long it would take to melt the glass, and the fact that i needed to have the flame larger, all rolled up to a failed attempt. i assume that my crucible will crack since i did not empty it, so i will buy a new one and try again, next time with better results hopefully. also i recently lost my hard drive so i am still climbing out of a big hole in getting my webcam to operate. we live and learn. it was probably too much to expect it all to work the first time, but i think that it will work if i allow more heat and more time to heat up. i will post more results in the future.

[Deb Hopeful Journeys]

I was hoping to see what was on the webcam today. I guess I will have to PM you sometime to make arrangements to come see you in person.

I am in N St Paul. Sounds like you are really cloes to me.

Deb in MN

[dogmaw]

Way cool!

[Heather/Ericaceae]

Welcome, Mark!!! I'm so glad to see you here. I love seeing your studio pics. Very inspiring. :) I'll keep an eye out for your next post. Cheers - H.

[laserglass]

as i stated in an eariler post, my first attempt in using my new lampworking furnace went bust. i could have made it work, but it would have taken a few more hours of melting, and i had other stuff to do that day, so i though that i would just end the experiment, and try again later. i went to axman and bought a few more curicubles thinking that the crucible would be cracked for sure since it was full of melted glass when i shut the furnace off. well to my suprise the crucible did not crack. i took it out and installed a new one for my next attempt. i have posted a photo of the crucible full of glass from my first attempt below. now that i have found/fixed several problems i think next time will go better. i am building a pyrometer for the furnace so that i can measure the temperature inside. i think that will help. fortunately i have a small pile of temperature controllers.