Well I has this offshore angle plate sitting on the shelf taking up room. It has probably been there 10 years or more and the sharpie markings that showed NOT SQUARE! was the reason why it was collecting rust.
It was also an awful machining job, with the slots unevenly spaced and between 11.5 and 13mm wide. One face seemed flat according to the surface plate, but the other face was not square - measuring 89:58" at one end and 89:49 at the other.
But it looked like the casting was sound so I started cleaning it up. The 3/8-16 tapped holes on the ends I added for a clamp system. So far so good, and the tapped holes were nice and smooth, and amazingly there were no hard spots. Seriously I have found pebbles inside cast iron so I didn't have great expectations with this lump. Then I found this...
The pics show a white plastic inclusion inside the casting which was exposed as I cleaned out the slots. It seems to be about 1/4 dia and less than an inch long. Does anyone have some insight into what that is? It feels chalky, like Bondo. Easily excavated with a screwdriver.
After an hour on the mill and another with the grinder I have a fairly decent angle plate. It will look better after some paint though.
Don
It was also an awful machining job, with the slots unevenly spaced and between 11.5 and 13mm wide. One face seemed flat according to the surface plate, but the other face was not square - measuring 89:58" at one end and 89:49 at the other.
But it looked like the casting was sound so I started cleaning it up. The 3/8-16 tapped holes on the ends I added for a clamp system. So far so good, and the tapped holes were nice and smooth, and amazingly there were no hard spots. Seriously I have found pebbles inside cast iron so I didn't have great expectations with this lump. Then I found this...
The pics show a white plastic inclusion inside the casting which was exposed as I cleaned out the slots. It seems to be about 1/4 dia and less than an inch long. Does anyone have some insight into what that is? It feels chalky, like Bondo. Easily excavated with a screwdriver.
After an hour on the mill and another with the grinder I have a fairly decent angle plate. It will look better after some paint though.
Don
