miked
Full Access Member
Because the precups are, I believe, inconel, they may or may not, sand down at a different rate than cast iron. Inconel is a lot like 300 series stainless to machine. Meaning, it may be tougher to sand than cast iron.
We had an auto machine shop bring us any IDI heads that they needed to be surfaced to us because of this.
Our Blanchard grinder was able to keep all the surfaces flat where his equipment could not.
But if I had an old junk set of heads, I would definitely give it a try just to see if it could be done, using a good quality hone stone to bring the pre cups level with cast iron after each pass of the sand paper, if it was found that the pre cups protruded.
You do need a stone that is perfectly flat.
We used to get small 5hp stream turbine's that used to wire cut (a small groove cut by the high pressure steam) from the high pressure side to the low pressure side along the split line of the 2 case halves.
We would TIG weld the wire cut using a weld procedure we developed.
Machine it in the boring mill to within .002 of the surface, then carefully stone the rest of the weld till we had a perfect blend with the rest of the surface.
Over the 30 years I worked for this company, we did 1 to 2 of these repairs a year.
Our customer did not use electric motors but ran all their pumps with these turbines in the older part of their plant. This was an old petrochemical plant that was built during WW2, and they probably had over a hundred of these turbines.
Sorry for the long story
We had an auto machine shop bring us any IDI heads that they needed to be surfaced to us because of this.
Our Blanchard grinder was able to keep all the surfaces flat where his equipment could not.
But if I had an old junk set of heads, I would definitely give it a try just to see if it could be done, using a good quality hone stone to bring the pre cups level with cast iron after each pass of the sand paper, if it was found that the pre cups protruded.
You do need a stone that is perfectly flat.
We used to get small 5hp stream turbine's that used to wire cut (a small groove cut by the high pressure steam) from the high pressure side to the low pressure side along the split line of the 2 case halves.
We would TIG weld the wire cut using a weld procedure we developed.
Machine it in the boring mill to within .002 of the surface, then carefully stone the rest of the weld till we had a perfect blend with the rest of the surface.
Over the 30 years I worked for this company, we did 1 to 2 of these repairs a year.
Our customer did not use electric motors but ran all their pumps with these turbines in the older part of their plant. This was an old petrochemical plant that was built during WW2, and they probably had over a hundred of these turbines.
Sorry for the long story
