Torch Firing - In Depth

Torch firing


You likely know how to torch fire, right? I am posting this as a review, as a reference page for those who are learning, and as a reminder that not all of your pieces need to be fired in a kiln.

I make a lot of tiny charms and necklaces with tiny silver elements on the last O ring (see at bottom of page for examples). Sometimes, I forget to put a tiny charm or that little element in the kiln and have already run the kiln for the day. Instead of being out of luck, I torch fire.

My rule of thumb is torch firing works for a silver piece 10 grams or less and for pieces that are solid with no fragile parts. Torch firing results in pieces of limited strength; kiln firing results in the strongest pieces.

Torch firing


Materials

  • Butane Torch
  • Fire Brick
  • Timer
  • Tweezers
  • Container of water

Steps
Below are my steps to torch file a piece with or without a CZ. As usual, I offer more info than you probably want to know.

  1. Position and support the piece on the fire brick. 
    • It is not really necessary to fully support a piece but I do, especially if it has a bail. 
    • If your fire brick is the light kind that you can dig out with the top of a fingernail or other tool, you can dig out parts to make sure all the parts of your piece are supported underneath. Or you can add fire blanket to support elevated parts of your piece. There is a good visual for this in the second video below.
    • I position my pieces so that I can move my hand smoothly and easily, pointing the torch over the piece’s surface. 
    • I also position my pieces so that if they cup or the edge curl upward, that this is consistent with the design of my piece. This will make more sense when you see this happen, as in the first video below.
    • You can torch fire more than once piece at a time, if the pieces are small and placed close to each other while not touching on the fire brick. 

  2. Begin moving the torch in a circular motion about 12 inches away from your piece. Move the torch in slowly toward your piece, which is consistent with the fact that silver likes change to be incremental. 
    • This is more important if is you are firing pieces with CZs or other torch-friendly elements.

  3. The hottest part of the torch’s flame is where the red arrow is pointing in the photo below.
Torch Flame hottest part


  • But, I do not use the hottest part of the flame in this process. Instead, I move the torch in and keep the visible flame from touching the piece. You will see why. 
  • When teaching in person, I have the person point the torch at only the fire brick and hold it there. If they hold it there long enough they will see where the flame is “pointing” by an orange glow on the brick. This is usually a surprise to them. It’s like calibrating the torch user, for they learn then where the flame’s hot spot is and where to point the torch for the best results.
  1. You want to heat your piece entirely and evenly, moving and pointing the flame over the piece’s surface in a circular motion.

  2. As the silver heats you will see steam and smoke then fire. This is the water and binder burning off. You can continue to heat it during those two stages. Then you will likely see your piece shrink, curl maybe, and begin to turn white.
  • Isn’t silver amazing in that it will cup and curl (if and when it is heating up unevenly) and then relax again back to its original shape? I think so. 
  1. Keep heating and watch as the silver turns this shade of orange, a shade I like to call Creamsicle (R) orange. 
Orange Glow Creamsicle
  • You adjust the heat and thus the color of your piece by moving the torch closer or away from your piece. 
  • The speed at which you circle your torch over the surface of your piece is not so much a factor. When I teach and can tell a lot about a person by observing how fast or slow they circle the torch. I am most often saying, “You don’t have to move the torch that fast. Slow it down."
  1. When the piece is the nice soft orange, start your timer.
  • The goal is to keep the piece this color orange for a full two minutes. 
  • Watch the piece to make sure you are heating it evenly. If you see plain white in a section or area, then it has cooled. To correct this, simply do better at heating your piece entirely and evenly. Do not focus the flame in that white area, because then the abandoned areas will cool and turn white also. Evenly and entirely is the best.
  • Some people torch fire up to 5 minutes. Simply know the longer you keep the heat on your piece, the more it sinters and the stronger the piece will be in the end.
  • Sinter = make material coalesce into a solid mass by heating it (which usually compresses it) without liquefaction (melting)
  1. If your piece turns this color, what I call hunter orange, back off the torch.
Orange Hunter Orange
  • Likewise, if you see little specs or pockets of bright, glowing orange — like red coals in a fire — on your piece, then back off the heat.
  • In theory if you have too bright an orange, the temperature of your piece is approaching the melting point of silver or 1,763° F. If you continue to heat your piece, the texture would melt. And if you further continue to heat  your piece, it would break apart, look like it was flowing, and then puddle and spring into spheres. 
  • I have taught many classes and watched a lot of novice torch firings and have never seen anyone melt their piece or melt the texture off their piece. Most people are afraid of doing this and do not heat their piece enough.
  1. Watch the timer. After two minutes of the desirable orange, turn off the torch.
  • If you have allowed your piece to cool in areas during the two minutes, then add the same amount of time it was cooled to the two minutes. 
  • You can torch fire up to 5 minutes, if you need.
  • This is where most novice torch users burn themselves. They reach for the tweezers or water and their arm touches the metal tip of the torch, which is still hot. Yes, I’ve done this, too.
  1. You can cool the piece one of two ways.
    One. Allow it to cool naturally, at room temperature, on the fire brick. Take this option if you have a CZ or other fireable element in your piece. This takes a few minutes.
    Two. Slide it to the edge of the brick, grab it with a tweezers, quench (dip) it in a container of water. Do not do this if your piece has a CZ or other firable element. 
    There is a good visual for this in the first video below.

Voila and ta-da. You’re done.


More Information

Here are some videos on torch firing from courses found at I Love Silver.


In the below video I talk about how long it took for the smoke and fire to develop. This was likely due to the small flame in my torch, which may have been running low on butane.



Examples of tiny silver element on the last O rings on necklaces

Necklace tidbit 1
Necklace tidbit 2
Necklace tidbit 3


For online courses in metal clay, go to I Love Silver, where you learn how to design and create your own silver creations.

© Kris A Kramer 2017