Casting mold tip
Posted: Sun Apr 06, 2003 10:36 pm
This kind of hooks with the casting failure thread.
I've been working on some long tubes, approx 4" diameter, with a 1 1/4" hole down the middle. I have had lots of probs with the core, falling over, just because of it's lack of thickness.
I seem to have it licked. I've started taking a chunk of rebar from Home Despot, and imbedding that in the core, casting the plaster around it. So far success. A couple of tips though. Make sure the rebar runs the entire length of the core, or the core tip (un reinforced) make break off. Also make the rebar go to the bottom of the plaster. I've also wired 2 pieces togeher to get the proper length. Works fine.
I don't know how thick it really needs to be, the rebar was handy. 17 guage wire(electric fence wire) worked fine to hold the rebar together, so I would guess it to work as an armature, if you needed a more complicated support.
The other thing is to let the plaster set well, no rushing, before moving the mold empty. I tend to steam my molds as soon as they are set, and that can cause issues, if the plaster isn't quite finished. I haven't noticed any damage from moving the molds with the wax in place.
Greg
I've been working on some long tubes, approx 4" diameter, with a 1 1/4" hole down the middle. I have had lots of probs with the core, falling over, just because of it's lack of thickness.
I seem to have it licked. I've started taking a chunk of rebar from Home Despot, and imbedding that in the core, casting the plaster around it. So far success. A couple of tips though. Make sure the rebar runs the entire length of the core, or the core tip (un reinforced) make break off. Also make the rebar go to the bottom of the plaster. I've also wired 2 pieces togeher to get the proper length. Works fine.
I don't know how thick it really needs to be, the rebar was handy. 17 guage wire(electric fence wire) worked fine to hold the rebar together, so I would guess it to work as an armature, if you needed a more complicated support.
The other thing is to let the plaster set well, no rushing, before moving the mold empty. I tend to steam my molds as soon as they are set, and that can cause issues, if the plaster isn't quite finished. I haven't noticed any damage from moving the molds with the wax in place.
Greg