Richard Huntrods

03-17-2004, 01:51 PM

This information likely exists in various other threads, but I thought it would be nice to make a bit of a summary in one place.

For those with wire furnace, a few questions:

1. What is the longest continuous stretch you run your furnace in hours?

That is, if you run it for 2 weeks, then turn it off, then fire it up a month later, this is 2 x 7 x 24 = 336 hours.

2. What size/type wire are your elements, and how are they configured?

3. What is the longest life you get out of your elments (hours if you have it)?

4. What is the highest temperature you run?

5. Cullet or batch? Anything of interest?

6. Noticed any problems (i.e. element fatigue before they die, etc.) Details?

Here's my numbers so far:

1. I started the furnace up Feb 8, and it's never been below 1850 since. (yet). Counting initial heating, that's 900 hours so far - all between 1850 and 2250.

2. 14 Ga. Small by melter standards. Kanthal A-1. Two elements, in parallel 240V power. Designed to 2400W (20A), but run 4.5 A at 1850.

3. Don't know yet. First set died because I bent them during a rebuild - only 420 hours. This set is 900+ hours so far.

4. Cook cycle is 2250F for 17 hours (5 hour "thermal equilibration" plus 12 hour cook. Squeeze and hold at 1850F, blow at 2060F. Charged at 1850 or 2060 or 2150 or (once) 2250 depending on what else is going on.

5. Spruce Pine. Started with 50/50 cullet/batch (3 charges), now 100% SP batch (3 charges). So far 6 charges on the current elements.

6. No problems so far.

-Richard

For those with wire furnace, a few questions:

1. What is the longest continuous stretch you run your furnace in hours?

That is, if you run it for 2 weeks, then turn it off, then fire it up a month later, this is 2 x 7 x 24 = 336 hours.

2. What size/type wire are your elements, and how are they configured?

3. What is the longest life you get out of your elments (hours if you have it)?

4. What is the highest temperature you run?

5. Cullet or batch? Anything of interest?

6. Noticed any problems (i.e. element fatigue before they die, etc.) Details?

Here's my numbers so far:

1. I started the furnace up Feb 8, and it's never been below 1850 since. (yet). Counting initial heating, that's 900 hours so far - all between 1850 and 2250.

2. 14 Ga. Small by melter standards. Kanthal A-1. Two elements, in parallel 240V power. Designed to 2400W (20A), but run 4.5 A at 1850.

3. Don't know yet. First set died because I bent them during a rebuild - only 420 hours. This set is 900+ hours so far.

4. Cook cycle is 2250F for 17 hours (5 hour "thermal equilibration" plus 12 hour cook. Squeeze and hold at 1850F, blow at 2060F. Charged at 1850 or 2060 or 2150 or (once) 2250 depending on what else is going on.

5. Spruce Pine. Started with 50/50 cullet/batch (3 charges), now 100% SP batch (3 charges). So far 6 charges on the current elements.

6. No problems so far.

-Richard