Hi Folks,
One of our customers passed along some helpful on an
inexpensive polymer dip solution for rapid prototype patterns being
investment cast.
The dip solution seems to help prevent investment erosion during the
burn out cycle giving a smoother casting. This has been an ongoing
problem with Rapid Prototype pattern material.
The solution is a household polymer solution called " Invisible
Sheild Surface Protectant" by Clean X. It normally used to protect
bathroom sinks & tubs from soap scum build up. It has the same
polymer as “Rainex” used on automobile windsheilds. It costs about $
7.00 a plastic bottle. It’s available at Ace hardware and other
stores.
To use the solution, pour it into a plastic snap top cup full
strength. Dip the RP pattern 2 or 3 times allowing it to dry between
coatings. Invest the pattern and follow the burn out schedule
recommended by your RP material manufacturer. It may not work with
all the different Rapid Prototype materials, but the customer noted
a big improvment in the resulting casting surfaces with the one he
was using. This solution may also be helpful to use on some of the
carving waxes especially prone to chew up the investment during the
burn out.
Special Thanks to Sam Glattstein in Boston for sharing the results
of his testing.
Regards to All,
Jim Sivertsen
United Technical Dept.