Old Ntric

I read a post Re: problems with PnP paper and nitric acid, in which
the responder mentioned that the Nitric may be too old. Is this a
common problem with Niric acid? I ask because here at the school we
have a Gallon of the stuff from the '70s and I can’t get reliable
results at a standard concentration for etching. Can anyone suggest
a supplier for ferric nitrate, and some concentrations for a decent
etch on sterling? Thanks Danny

Use Bryant Labs in Berkeley California. Nice people to work with.
Decent etch is 1 cup of ferric to 2 cups of distilled WARM water.
Etch away!

-k
Karen Christians
M E T A L W E R X
http://www.metalwerx.com/
Accredited Jewelry Instruction

Can anyone suggest a supplier for ferric nitrate, and some
concentrations for a decent etch on sterling? Thanks Danny 

Hi Dnny Since I’m in Canada, my supplier is probably not much use to
you. I’ve been using a ferric nitrate solution of 200 gm ferric
nitrate to 300 ml of distilled water. I started out with a much more
dilute solution which was taking 4 - 5 hours to etch. Each time I
made a new solution I tried different ratios. This latest one is
etching nicely in about 2 hours.

Sandra
Goss Design Studio
Sandra Noble Goss
Owen Sound, Canada.