casting is OK but after kenching the tree in Hydrochloridric acid
to remove investment a white film covers the casting pieces,
difficult to remove. I the temp of the flask 700degres, pieces are
thin. near filigree work) the pieces are quite thin and using sand
blasting or high pressure water jet will deform the pieces thsk by
advance for your help.
Don't quench in acid. quench in water. Quenching in acid won't
improve the situation, and can be quite dangerous. After quenching in
water, then you can use an investment remover if you wish, some of
which are based on acids, but not all. The commercial products work
better than HCl. Some, based on fluorides, also need to be used with
care, but can work quite well. I'd suggest contacting the
manufacturer of the investment you use, or alternatively, your metal
supplier. They often can offer specific suggestions that work best
with the products you're using.
Alternatively, an ultrasonic generally will do the job nicely. It
may be easier to cut the castings off the tree and finish cleaning
off that film afterwards.
Steam cleaning is also useful, and is much gentler than a high
pressure water jet.