Ambient studio temperature

Damselfly · #1 2010-10-13, 11:50am

There was a discussion on Wet Canvas a few years back that comes to my mind every winter.

A beadmaker said she was making beads out in her unheated garage, and in winter the temp could get to 55 degrees or so. She noticed she was getting a lot more cracks in her beads, and wondered if it was because the garage was so cold.

Someone in the discussion said that it was ridiculous to think that it was due to the temperature. Since soft glass beads melt at such a high temperature (respectively), then the twenty five degree difference (80 degree summers vs. 55 degree winters) would make no difference.

However, it seems to me (and perhaps I'm wrong) that it's not exactly the difference in ambient temp as much as beads will cool faster in 55 degrees than they would if it was 80. After all, if I want to cool my brass marver, it'll take longer to cool if it's just sitting out than if I press it against something cold.

I'm just curious if my reasoning is sound, or if ambient temperature really doesn't make a difference.

Edited to add: It really wouldn't make a difference for my working style, because I always put my beads into the kiln with a slight glow. However, when I first started working, I always put them into the edge of the flame until the glow was gone, so that's when I was thinking it might cool faster, and you would need to change your work routine depending on ambient temperature.

scoutycat · #2 2010-10-13, 3:54pm

I'm with you - glass chills faster at 55 than 80. The person who cried ridiculous's logic doesn't hold either - you can apply the same reasoning to a coffee warmer or crockpot, and you would conclude that those measures wouldn't help since the temp differential wasn't significant compared to the amount that the glass needs to be heated to melt. However, anyone who has used them knows that that extra hunred degrees makes a big difference.

BKScott · #3 2010-10-13, 4:00pm

I first began in an unheated garage and the ambient temp. got down to 40º's , with me sitting on a heating pad...LOL! Anyway......my experience was that if I put them into the kiln glowing on a metal rest so they didn't touch the floor, they were fine. But if they cool in the ambient temp too much, yes, they cracked. And another thing I found out the hard way......My studio is STILL outside in the garage, and now heated with a pellet stove, but I have to wrap the anealed beads in a blanket to bring inside because of the extreme temp difference to get to the house for cleaning. So my experience is that the ambient temp is a factor at least here in the North East!!

dusty · #4 2010-10-13, 10:26pm

I can sometimes see my breath in my studio. In my experience, glass rods thermal shock worse when it's cold.

Art of Hand · #5 2010-10-14, 2:56am

I also agree with your theory. I prefer to make hollow beads at night. Normally it is colder, and I found that I had more chances of having my first disk cracking when it was cold while I worked the second disk, compared to when it was warm in the room - using the same speed to make a disk/hollow. Same applies when I make multipe disks on a mandrel. In winter I have to make less disks/mandrel. Using the same rythm or flashing the disks in the flame, while making another disk on the mandrel.