Anneal section of lengthy trim?

Steel or Aluminum?

It's all pretty easy, your over thinking it.

The key point is that you want to heat the metal to a certain temperature, "too cold" and you will not soften the metal hardness, "too hot, and it melts.  So.........try this.  Using your acetylene torch, turn on only the acetylene gas.  It will produce a very black carbon flame.  Use this carbon flame to coat the metal you want to anneal.  You will not want to work this on that pretty tile floor because it's going to be messy.  I like to set up three of four jack stands at the same height, lay the metal on the stands, coat it, and do not touch the metal (after your coat it in carbon.  Now your ready for the fun.

Reset the gas mixture using oxygen to a normal soft blue flame.  Use the largest torch tip you have, and build a nice large soft heat source.  Remember, your just heating metal, not trying to weld metal, just a soft flame is all you need.  Now start at one end of the metal, start heating the first foot, keep the torch about 6 to 10 inches away, and "KEEP THE TORCH MOVING" over the area, you want the heat spread out.  At precisely the point (the temperature) burns off the carbon you have the aluminum annealed.  Just keep working down the length until the entire trim has been done.  Then do nothing, just let it cool to room temperature naturally.  Do not use air, water, or oil on the hot metal.  You are not trying to harden the metal, or trying to shrink the metal, just heat it up and let it cool, and it will be annealed.  The key is the temperature, and you used the carbon as your temperature indicator.  The metal will return to mill finish after the carbon is burnt off.

I have heard, not personally tried it, but you can use a wax candle carbon flame, or even a Mark-a-lot ink pen to coat the aluminum.  Just heat the metal until the ink or carbon burns off.  You might be able to use a MAP gas torch as your heat source?  Using a acetylene torch with the two separate gas adjustments is actually very easy.  You can do the entire step in ten minutes.

There's no need to reharden the metal after it is straightened because it will be "work hardened" from bending and time just like you see on a very old piece of copper tubing.

Good luck,
John

   

Hi Friends,

If I had more time... I would love to experiment with the procedure that John described just for the hell of it. Grab some old stock and get to business. I can't wait to here about your results, Allan.

Cheers,

Rod