Polymer coating for rapid prototype patterns

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.

One of our customers passed along some helpful on an
inexpensive polymer dip solution for rapid prototype patterns
being investment cast. Etc, etc. 

Can you be a bit more specific, narrow it down to an RP brand…
envisionTEC, DWS, SolidSacape" Which material" What are you
casting… gold, platinum" What investment"

Hi Charles,

The customer was using patterns made on DWS rapid prototype machine.
I believe he used R & R Plasticast investment. He cast both karat
gold and platinum using the coating material and had smoother cast
surfaces on both materials. Sorry, I didn’t do the testing, just
passed on the about the coating material.

Some good on burning out RP resin patterns was presented
in a paper at the 2007 Santa Fe Symposium entitled “Improvements in
the Burnout of Resin Patterns” by Dr. Ian McKeer at SRS Ltd. in the
UK. They were experimenting with Rapid Fire burnouts. GoldStar
Investments has a Rapid Fire burn out schedule for their Omega+
investment on their website. A number of people I’ve talked to have
tried the Rapid Fire burn out on Envisiontec patterns and said the
surfaces were better but not perfect.

Best regards,
Jim Sivertsen
United Technical Dept.