I need some advice on how to cure a problem I am experiencing with
my injected wax models. I am ending up with what appears to be an
"Orange Peel" effect on my models
as with everything ‘it depends’
Is your model particularly thin?
Is your sprue large enough?
Since the talc is only to let the air out, brush it out of the model
cavity with a small soft paintbrush.
I have a pattern with long thin wires that didn’t fill well.
Remembering another jeweller leaving his patterns on to of the wax
injector to warm them up, I made a shallow flat wooden box with a
thin aluminium top, then mounted a 15 watt soldering iron inside.
This gave me a surface at about 35 deg C. leave your moulds on it all
the time and the wax will flow much better. If it is too hot layers
of card will insulate.
Conversely thick patterns need the mould to be allowed to cool
The ripples are from the wax momentarily freezing and then more
molten wax flowing over the cold ridge, a warmer mould will stop
Have you tried a different wax? Or a new batch, I sometimes wondered
if it gets old and the properties change for the worse.
I have tried to be scientific about problems I have had, once you
start splitting the wax flow you can trap air bubbles, keep it
simple, I have one pattern that nearly always gets a bubble, no
matter what air vents i have cut, still don’t understand why.
The MJSA do an interesting book, ‘The AJM Guide to Lost Wax Casting’,
http://www.ganoksin.com/gnkurl/ep820v and there are Santa Fe
Symposium reports about various aspects, but I suspect that it is a
cold mould problem.