Monday, August 26, 2013

Heating Kydex for Molding

This Tips and Tricks article will focus on heating your Kydex (or Boltaron) in a counter top toaster oven.  I’ve seen a lot of confusion, complication and mystery surrounding this process, but it really could not be any simpler.  Here’s the bullet list:

  • ·         Wire rack in oven set to toast at max temp

  • ·         Material in, texture up, watch for white line to fade, rotate

  • ·         Watch for the “cheese burger effect”

  • ·         Remove to mold, repeat, shut oven off between molds

  • ·         ????

  • ·         Success/Profit

The Long Technical Explanation

What kind of oven should you buy?  It doesn’t matter as long as it is big enough to fit the material you need to heat.  I prefer the larger ovens you can find at any big-box store for around $50 with about a 10”x12” rack area.  I prefer the models that use quartz elements, not metal.  They heat up faster and I think provide a more even heat.  To tell the difference, the quarts elements look like opaque white tubes, metal elements look like… metal.  Just remember, if you use an oven for Kydex you will never again be able to use it for food (unless you enjoy food that tastes like burning tires, then you’ll really appreciate the food out of a Kydex oven).
How should you set up the oven and what settings should you use?  All you need is the wire rack set in the low position.  For settings, select toast and crank the heat to max temp.  Never use bake, broil or convection settings, you want all of the heating elements on.  Some of you might be asking, why?  I thought Kydex should be heated to a certain temp over a certain time?  Nope.  That is over complicated.
The heating elements in these little ovens are only a few inches away from the material.  When you turn them on, they heat up to 1000+ degrees in a minute or two and that glowing, radiant heat is what you should use, not the temp setting on the dial.  Sure, you can set it for 230 degrees, but when those elements are on they are heating your material at max temp until they shut off.  Then you’re stuck with whatever ambient heat is left in the oven and that is not as efficient as strait radiant heat off the elements.  The goal is to heat the material enough to mold, but not so much that the surface takes on a “shiny” look.  All you have to do is keep an eye on it, so let’s talk about what you’re looking for.
Most of the material you’re using has been chopped or scored and snapped off of a full sheet.  Any edge other than the factory edge will probably have a faint white look to it where the material stressed during the cutting process.  This is a great built in temp gauge for your Kydex (like the little thing that pops up in Turkeys).  Start with a cold oven and toss your material into the center, textured side up, with that white line facing you.  Crank up the heat and watch that white line.  You’ll see it start to fade back into the base color of the material in between the bars of the wire rack.  As soon as you see this, open the oven and turn the material 180 degrees so the back edge now faces you.  Why turn it?  Again, these tiny ovens are not consistent in their heat output and the back of the oven is always hotter than the front.  So, just like turning your toaster strudel, you need to turn your Kydex.

Now, start looking at one of the edges that falls in between the wires of the rack, or hangs off the front.  What you’re looking for I call the “cheese burger effect”.  You want that perfect, melted cheese corner you’ve seen on fast food commercials.  It will tell you that your material is ready.  Reach in and grab it and as you pull it out it should feel like a piece of cooked lasagna noodle; floppy like a sheet of rubber.  Move it to your press and do your thing.  When you are done molding, turn the oven off.  If you don’t, you’ll burn the wire rack into the next sheet of material that you put in.

Here is the downside to this quick heating process.  If you get distracted or forget what you’re doing you will burn the Kydex.  At best, you’ll ruin the material and start over.  At worst, you’ll need to evacuate the area until the deadly fumes clear out.  So stay on task, don’t answer the door or your phone or check your email, and you won’t have to know what it takes to make Kydex look and feel like a pork rind.  And don’t ask me how I know ;)
So, while the explanation is a bit long winded, the act is very fast and simple.  Don’t worry about temps and laser thermometers, just get it hot, get it in the press and do it yourself!


  1. Great info! I'm A just wing it kinda guy as well just get it done!