Solution for removing investment

Perhaps everyone also does this; I hold my completed tree
(designs down) between my first two fingers, just under the
button and with my heavier chasing hammer hit it repeatedly till
most of the investment falls off. It isn’t necessary to hit it
hard , just a lot …for about 3 minutes a tree. It works best
when it is dry and I usually do it outside over a bucket just to
keep the neighbours curious about the peculiar noises. This gets
rid of 90~95% for me. I appreciate the vinegar tip. I’ll try it
next time. Darryl

Just be very, very sure you’re wearing a respirator capable of
handling very fine dusts. NOT just a cheap dust/mist painting
mask either. A good respirator. Without it, This method is a
dangerously fast track to silicosis. Investement knocked out dry
like this is even more dangerous than the raw material you mix up
to invest the flask, and keep in mind that the particle size we
are concerned with here will not be visible floating in the air.
You may THINK you’re keeping your face out of the cloud of dust,
but it’s the larger, faster spreading cloud you cannot see that
is of real concern. Perhaps the moral to all this is that dry
knockout of investment is not, generally speaking, an especially
intellegent idea unless you’re being VERY careful with the needed
precautions…

Peter Rowe