Mixing investment

Jewelry Discussion
1

The question I have is about the water that is used in mixing
the investment.The tap water in this area of Kentucky has a
“VERY HEAVY” limestone level , enough that stalagmite formations
from the faucet are normal from the small drop of water left on
the outlet after turning the water off. Ok , the question is .
Will this heavy lime content effect the investment and cause
defects in the final castings ?

Timothy
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2

Hi Tim, I would suggest calling your investment manufacturers
800 number and asking them about your water situation… it may
have an effect. What problems if any have you had?

" Ok , the question is . Will this heavy lime content effect the
investment and cause defects in the final castings ? "

Daniel Grandi
Workshop http://racecarjewelry.com/page03.html

3

Timothy, I would recommend using distilled water. I switched to
it over a year ago and find that I have a better and more
consistant results than using tap water. Various minerals and
ions present in tap water can affect the work time of investment.
The quality of water varies thoughout the year and can cause
unexpected problems. I like to take out any variables in my
process that I can. It makes it easier to troubleshoot should a
problem arise.

Brett Gober
Freedom Design & Contracting

4 
 I would recommend using distilled water. I switched to
it over a year ago and find that I have a better and more
consistant results than using tap water. Brett Gober

G’day; I don’t do casting (other than the odd cuttlebone job at
rare intervals). But it seems to me from what I have been reading
that one of the problems involving investments are the bubbles in
it, and the reason why folk use vacuum pumps to ‘debubble’ it.
I suggest that distilled water works better because having been
boiled at normal temperature, (100C) very little air is
dissolved in it. Pressured tap water contains a lot of air; the
cooler the water, the more air will dissolve in it which is the
opposite to what happens with most soluble solids. (Why goldfish
gasp at the surface of a small pond in hot weather) Leave a
glass of cold water in a warm room and in an hour or so you will
see lots of bubbles on the glass, as the air comes out of
solution… My suggestion is that casters might like to try
boiled and cooled water to make up investments. De-aired water
thus made will slowly redissolve air as the day wears on, but if
boiled early, and perhaps left in the kettle to cool, and not an
open mouthed vessel, it would not contain much air several hours
later. And of I wouldn’t dream of suggesting that casters ought
not to whip up their investment as though it were cream :slight_smile: –

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    (_______)  In sunny temperate Mapua NZ -

Autumn’s here…