heat treating rock. kiln firing jan 9th 2010   1 comment

firing jan 9th 2010

temperatures taken from top peep hole

start 11:15- both switches on lowest, peep holes open lid propped

12:15 top switch off aprox 125 C

12:50 top switch back on lid closed apron 170 C

1:10 both switches on lowest 270C (500F)

1:31 top switch one dot up bottom on low 320C

1:52 top switch on low 380 C

2:23 top switch one up from low (1/2 way between low and med)  bottom switch 2 up from low (1/2 way between low and med) 450C

2:50     520C  (950F)

3:21 dials both on med     580 C

3:46   620 C both dials on lowest top peep hole plugged…   needs to go higher i will go back out in 10 minutes and turn it up again. rocks started popping no violent explosions just small pot lids

4:07 kiln is back up to med

4:31 dials are in-between medium and high (top and bottom) 720 C

4:47   780 C  more potlids, to large potlids when i opened the bottom peephole
oops not going to do that again…

5:34   950 C again more potlids.  dials are both on high.  i don’t think much will be left of the hard grainy ones. many went in though so that many potlids can be expected

5:59 1020C  pyrometer is out of the kiln now and peep hole is plugged. dials are  turned on high fire

6:29 peeped in the hole, no sagging yet, looks hot though!

7:02 no sagging brighter colour now

7:30 cone 05 slightly sagging

8:03 cone not any more sagging. elements not making any sound, pushed kiln sitter up slightly and cone melted enough to shut the kiln off. i need to check the kiln to see why it couldn’t reach the right temp

8:16 1160C 2250F  my mom convinced me to put the pyrometer back in and plug the kiln back in. there was enough cone to trigger the kiln switch.

8:31 1230 C 2275 F

8:52 1280C  2350 F

finish 9:00 turned kiln off closed top peephole

and heres the photos to go with it.

the kiln didn’t get hot enough and some of the rocks turned into gravel unfortunately. overall not a very successfull firing but i learned not to put that type of rock in the kiln as it doesn’t glass up at all anyways.

the photos with two rocks in my hands are before and after shots of pieces off of the same stone.

a piece of obsidian turned into pumice which is interesting. i might make glass fishing floats. my next firing was far more successful ill be posting that soon

thanks for reading

the teenage caveman


One response to “heat treating rock. kiln firing jan 9th 2010

Subscribe to comments with RSS.

  1. Pingback: heat treating rock. kiln firing jan 9th 2010 « the teenage caveman | Wood Fired Ceramics

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: