Yup, it works a treat. I recently finished a bow for a guy who had cut the fairly skinny Yew log a year ago. He wanted 50#... I wouldn't have made the 50# if it wasn't for heat tempering, I also combined a little reflex into the heat treatment.
See my blog here for a little tip, it speeds up the heat treating and protects the sapwood all in one go. Basically you clamp some offcut strips of wood to the sides of the bow, it directs the heat and stops it leaking round and cooking the sapwood. Less wasted hot air=less wasted time, it still isn't a quick process but you get a more event heat without the dark spots effect.
http://bowyersdiary.blogspot.co.uk/2013/02/yew-longbow-more-heat.htmlIf you read the posts before and afterwards, you'll see the whole build along.
Del
