[GreenLS6]

I was actually going to suggest a sonic density tester,The compressed steel might show better. I use FLIR thermal imaging all the time being a firefighter, in theory the torch might work. The compressed steal might hold temp longer being denser as it cools..... [img]<<GRAEMLIN_URL>>/dunno.gif[/img] But the cameras we use wouldn't be sensitive enough. GOOD LUCK

You never succeed if you don't try....