This is what I did and it worked great. I ground a groove in the first caul so that the crown of the boo would fit in it. This was the steam bend. Then when it had cooled I moved it to the second caul so that I could dry heat from the inside of the bend(the outside of the boo). I usually have to re grind the gluing surface because it goes a little convex when you steam bend it but it's nice and flat