> Douglas Binder wrote:
> -------------------------------------------------------
> It has been a long time since I last cast a cylinder but I will try to
> remember some of the issues. It would be worthwhile to search out my
> posts on the subject. One thing that comes to mind is that the PLA can
> be porous which allows the plaster to enter the mold. I solved that by
> spraying a clear paint onto the mold.
>
> The other thing that comes to mind was that I never got a totally clean
> pour. The cylinder bore always had tiny pits. Oil retention pits was
> what I called them. I had decided to just go with an iron liner but got
> side tracked when I started to build airplanes. *Slightly* more
> expensive than mopeds. My poor bike sits on the DIY dyno waiting for
> some love. Maybe I'll get back to it once my second plane is flying.
about the bore thing, I draw the cylinder with a 2mm smaller bore than it's gonna be. so hopefully this is enough to get rid of the possible pitting, we ( graham mostly ;)) will see how it will turn out