My steam bending chamber (3-inch steel pipe x 60 inches long with 1500 watt electric heater in one end) 3/4 full of water, quickly comes up to the pressure switch set point of 10 psi, and has worked ok for some years, usually bending hickory for Windsor chair backs. Now, when I try to use it on white oak, the wood has a nasty black color. Why? One theory has something to do with the tannic acid I believe is present in the oak, but I'm no chemist. Is there a reaction between the steel pipe and the oak? Any comments are welcome. Dave
- posted
19 years ago