As a carpenter the running joke when my kids were younger was to use a board stretcher to make things work.  Well over the holidays I was lucky enough to get some metal working tools.  My youngest went with me to buy them.  One of the things I wanted was a shrinker stretcher.  I had trouble finding the unit at Princess Auto, even the sales guy had trouble.  Several times my son thought I was BS'ing him as there is no such thing he says.  It is not real.  So had a chance to set it up today along with the other things I bought and proceeded to make some art work.  He did not see me do it, so just showed him this piece of metal.  Left him wondering, then told him I used a shrinker to do the work.  Oh how our words come back to bite us.