Heat Treating Beryllium Copper Propellers
I recently contacted Jim Schaefer of ABC Props for information on heat treating Beryllium Copper Alloy Propellers. Here is what Jim had to say.
On Our Alloy We DE-STRESS at 340F for 20Min (VERY IMPORTANT) Then re ramp the temp to 594-608F at a rate of 28.8' F per min We hold for 40 min to 1.5hrs depending on the prop We then AIR COOL at room temp on a cool copper plate Drawing the heat out of the drive side of the hub. The prop must be CLEAN Fingerprint oil can even cause hot-spots The blades must not touch anything during heat up or cool down. Final sharpening is done after. Higher temps and longer time seam to have little effects. Salt or Lead bath Heat-Treat is a + if one can control the temp within 0.5'F The lower the BE content the Higher the Temp and Time Our Alloy can and has Been Treated to a Rc45 in production apps.by other Co. The Major proplem I see with breakage is do to Thinning Bar-Cutting Back-Cutting Prop-Racing Other prop Cuts are far more effective Proper Sizing and strut placement of Props seems to still be the major problem. Changing from a Copper Alloy to a Stainless Alloy only cures one problem. THE BOATER STILL DOES NOT KNOW HOW TO WORK THE PROP AND SET STRUT HEIGHT AND ANGLE. All Manu. work very hard to let the average boater go faster. Set up is still the major factor. By the way Jerry at Seaducer set the records with Our Alloy NONE WERE HEAT-TREATED. Proper Sizing and Set-up was the KEY. THE MAN CAN GO FAST. The Black Magic of Props Go Fast Jim