Daniel Grandi: Thanks for your discertation as to the advantages of
the Tivac inserts. I am planning on giving them a try. Currently I am
using perforated flasks and can only fit four 4X6 flasks in my oven
at one time. I figured that by using standard flasks with the Tivac
inserts, I can fit nine 4X6 flasks at one time in my kiln. That alone
will make the changeover worthwhile.
I also knock my castings out of the investment when cold to prevent
cracking and also eleminates the need to dry the investment for
disposal. I can imagine that the solid flasks with Tivac inserts will
make knocking out the investment easier.
Thanks again for sharing your knowledge with us. As someone that has
had to learn most of what I know the hard way, I appreciate the
pearls of wisdom that you and others on this list share. Also special
thanks to Hanuman for hosting this website.
Ken Gastineau
Berea, Kentucky
Dear Ken, Please note: If you knock your flask out cold you MUST have
a great vent system. These air particles can eventually kill you. The
silica dust is a nasty thing. Coal miners get black lung. Casters who
aren’t careful get Silicosis.
Best Regards,
Todd Hawkinson
TR the Teacher
T.R. Hawinson, Ltd
Todd: Thanks for the warning about silicosis. Yes, I am aware of the
dangers of investment. I knock the investment from the flasks
outdoors and also use appropriate safety equipment such as a good
respirator. Quenching flasks in water requires the same precautions
as investment becomes airborne in the steam.
Ken Gastineau
Berea, Kentucky
Dear Ken, Please note: If you knock your flask out cold you MUST
have a great vent system. These air particles can eventually kill
you. The silica dust is a nasty thing. Coal miners get black lung.
Casters who aren't careful get Silicosis.
Hi Ken, Todd is absolutely correct… the dust is dangerous… It is
easy to build a machine using a hydrolic press ( used by car
mechanics , Cheap used…) to press the investment out of the flask
when it is cold…If you also mount 2 small air hammers ( also from
a mechanics used tools) on both sides of the flask, it will hammer
the sides of the flask while the press pushes the investment out…
we had built such a device about 10 years ago… put a big bucket
underneath to catch the tree… wrap the whole thing in plastic or
rubber and hook a blower/dust collector to it and you have a clean ,
dry breakout system.
With another air hammer, if you get very powerful vice grips or
something like it to grip the tree button, and make a device to hold
the vice grips… you can use the automotive air hammer to hammer
against the button… and all the investment will come off the tree
( actually about 98 %)
The Tivac insert will help your castings and it will ease the
breakout process
Best Wishes, Daniel Grandi We do casting/finishing for designers,
jewlers and people in the trade. Contact sales@racecarjewelry.com
Dear Ken,
This tip comes right from Ultravest. I do as they say. I like to
quench because it gives me the right annealed material I like. The
tech support says to wait the necessary time and to quickly plunge
the flask into a bucket of water. If you go deep enough with the
flask tongs there is no steam coming from the water. It will be
contained in the water and not become airborne dust or steam to
breath. Some people I’ve seen cast put the flask only half way into
the water. That is where the problem comes. I’ve also seen cast
parts bent by some of those hydraulic presses for investment removal.
They then sit in the very expensive corner.
Best Regards,
Todd Hawkinson,
TR the teacher
T.R. Hawkinson, Ltd.