Posted by benny (68.78.128.91) on October 03, 2008 at 08:30:28:
In Reply to: gray color on propeller blade posted by Samson S. Barrameda on September 19, 2008 at 10:29:22:
: Hi
: We're doin chromic anodize and the problem we have is the gray/black color circular shape on the edge of the blade which to me is like burn on the thinnest area of this C130 aircraft propeller blade.The temperature is right and we apply 40 volts within 10 minutes time frame and we're using 150 Amperes diode type rectifier........ What are the characteristics and causes of a burn if indeed it is........Please enlighten us....Thanks
It sounds like your voltage is going up too quickly and allowing the discoloration since there is not sufficient coating on the part to require the additional voltage.