David,
We have tried everything from smoke to positive air pressure under a liquid
and none seem to work all that well. I'd use a combination of methods
starting with about 5lbs of positive pressure along with a stethoscope. If
you cannot find the holes using this method then on a thoroughly cured
pattern ( in the box for 5 to 6 hours) use the positive pressure and
submerse the pattern in water ONLY WITH POSITIVE PRESSURE APPLIED. You will
find the hole(s) via visual and then with air still being applied remove the
part from the water, wipe off the part, mark the are of concern with a
marker and then remove the air. These two methods seem to work best for the
parts that we do (small jet engine type parts).
I hope this helps
Karl Denton
Senior Engineer
Stereolithography and Prototyping
Casting Operations
Williams International
-----Original Message-----
From: Kreitz, David [SMTP:david.kreitz@lmco.com]
Sent: Wednesday, June 02, 1999 8:36 PM
To: rp-ml@bart.lpt.fi
Subject: QuickCast Pattern Leak Testing Methods
What methods/equipment/techniques are available (and tested) to
check
QuickCastTM patterns for leaks? I have found a smoke machine at
"www.thesmokemachine.com/homepage.html" that has been developed for
the
automotive industry to find vacuum leaks. Has anyone ever used one
of these
for testing QuickCastTM patterns? Does the non-toxic, (vegetable?)
oil based
smoke cause the QuickCastTM parts to soften or swell? Are there any
foundry
related problems associated with it's use? ....etc.....etc.....
Any help would be greatly appreciated. Thanks.
Dave
David J. Kreitz
Rapid Prototyping Lab Supervisor
Lockheed Martin - Electronics & Missiles
5600 Sand Lake Road - MP 185
Orlando, FL 32819
phone: 407 356-7375
fax: 407 356-7376
email: david.kreitz@lmco.com
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
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