using microwaves to dewax a plaster silica mould ?!?
Moderator: Brad Walker
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using microwaves to dewax a plaster silica mould ?!?
Hello All,
I have a rather large mould - about 1 cubic foot with a reasonably large wax model in it - the wax model has lots of detail in it. I'm looking for non-traditional ways to de wax the mould. I read a fair bit on microwave oven techniques to dewax a mould. All requiare a rather WET plaster mould. I'm not sure how successful a cured mould is with the microwave approach !!
Has anyone tried the microwave approach to dewax larger moulds (> say 6"x6"x6"). I've had decent success but with small moulds - not large ones. Large moulds are a greater investment of time, energy & "soul" - so hate to screw this up - but am also loath to dewax with steam boiler tech.
Krishnan
I have a rather large mould - about 1 cubic foot with a reasonably large wax model in it - the wax model has lots of detail in it. I'm looking for non-traditional ways to de wax the mould. I read a fair bit on microwave oven techniques to dewax a mould. All requiare a rather WET plaster mould. I'm not sure how successful a cured mould is with the microwave approach !!
Has anyone tried the microwave approach to dewax larger moulds (> say 6"x6"x6"). I've had decent success but with small moulds - not large ones. Large moulds are a greater investment of time, energy & "soul" - so hate to screw this up - but am also loath to dewax with steam boiler tech.
Krishnan
--
If I could I would, but I can't so I won't.
Still I love to cast glass ....
If I could I would, but I can't so I won't.
Still I love to cast glass ....
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- Location: Halikko, Finland
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- Location: norfolk, va
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- Posts: 270
- Joined: Tue Mar 11, 2003 7:33 am
- Location: Halikko, Finland
Jerry Flanary:
... the melting wax is just going to seep into the plaster (my guess). You need
the water in the plaster to resist the molten wax (my opinion).
That is my experience, too. I tried once to remove the residue vax by burning acetone in the mold.
The result was a beautiful cast, filled with
ugly black flakes.
-lauri
... the melting wax is just going to seep into the plaster (my guess). You need
the water in the plaster to resist the molten wax (my opinion).
That is my experience, too. I tried once to remove the residue vax by burning acetone in the mold.
The result was a beautiful cast, filled with
ugly black flakes.
-lauri
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- Joined: Tue Sep 09, 2003 11:11 pm
- Location: norfolk, va
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- Posts: 14
- Joined: Mon Aug 18, 2003 6:59 pm
I suspect that the ugly black flakes are from burnt carbon (== soot) that got left behind. It is VERY hard to clean out the soot since it sort of smears itself with the slightest hint of moisture. I've had black spots/flakes in the casting when I had some unburnt wax left behind in an undercut or some "hard to reach" place within the mould.lauri wrote:Jerry Flanary:
... the melting wax is just going to seep into the plaster (my guess). You need
the water in the plaster to resist the molten wax (my opinion).
That is my experience, too. I tried once to remove the residue vax by burning acetone in the mold.
The result was a beautiful cast, filled with
ugly black flakes.
-lauri
Krishnan
--
If I could I would, but I can't so I won't.
Still I love to cast glass ....
If I could I would, but I can't so I won't.
Still I love to cast glass ....
-
- Posts: 270
- Joined: Tue Mar 11, 2003 7:33 am
- Location: Halikko, Finland
Sure the flakes were unburnt carbon.
The acetone was a liquid, squirted into the mold and lit.
OUTDOORS !!!
It burns off perfectly clean. I expected it to burn
off the wax residues as well but apparently the very high
heat only made it to seep deeper.
When cooking the glass, that wax gassed out making
bubbles into the glass. Without oxygen the carbon
compounds of wax disintegrated and left the carbon flakes
inside the piece.
-lauri
The acetone was a liquid, squirted into the mold and lit.
OUTDOORS !!!
It burns off perfectly clean. I expected it to burn
off the wax residues as well but apparently the very high
heat only made it to seep deeper.
When cooking the glass, that wax gassed out making
bubbles into the glass. Without oxygen the carbon
compounds of wax disintegrated and left the carbon flakes
inside the piece.
-lauri