Trying to fill the medium flask part

Hi …again

IB4m only using 4" X 6" flasks in vacuum casting…here is
the question…

Sometimes the “central part” in the flask doesnB4t fill, I have heard
something about “square sprue”, but I haven find the way that this
can help to fill better(I havenB4t try this yet) … …the
problem is turbulence?..How can I stop the turbulence?,
…the wax need “special” sprue?,… more
temperature?

Thansk …again

Alberto
@pareja44

Hi Alberto, Please go to my website and on the front page, you will
see a link called http://www.racecarjewelry.com/page03.html Here ,
you will see an entire section on simplified lostwax vacuum casting
that will help you out.

Many times, when vacuum casting, you will have areas that do not fill
because you may need additional vacuum ( we have an insert that goes
in the flask that will drastically increase your vacuum capabilities)
or you may need to adjust your oven temperature about 100 oF higher
than you are at.

We cast about 6000 pcs/ week when we are busy and we have never had
to turn a flask upside down to release “gases”. If there were any
gases in the flask, they would be sucked out the minute you put the
flask on the vacuum table. The only thing you could accomplish by
turning a flask upside down inside an oven is to increase your chances
of getting “Dirt” in the flask from the firebrick the oven is made
from. We have moved to a much larger facitity last year (4000+ Sqft)
and have greatly increased our casting and finishing capability . We
will be posting new pictures soon that shows some of our new
additions… Automatic rubber mold clamping ,Vacuum wax injectors and
Oxygen generators so that we no longer have to buy oxygen for our
torches.We use 2 torches on 2 crucibles so that we can melt 700 grams
in each crucible . This allows me to cast a flask every 2 minutes(
each flask takes only 4 minutes /melt). I hope visiting the website
helps…

Daniel Grandi Casting and finishing in gold, silver,bronze, brass and
pewter for people in the trade http://www.racecarjewelry.com Tel:
401-461-7803 Eastern Standard time