2 Silver questions

Am I correct in thinking that if I substitute high melting point
silver solder for enamel melting point silver solder that the joint
will be even stronger and less liable to discolour as the Silver
content in the solder will be higher ? and if I adopt this approach
are there any down sides to it, other than it needs greater heat
control when soldering.

Secondly …I use Zam to polish my silver items up …but I now have
quite a lot of “ZAM bits” that fly off when I charge my felt. Is
there any way of re using these bits (e.g. reconstituting them into
another block rather than small bits) or reducing the amount of bits
that fly off when I charge my felt …

Thanks Paul Townsend
www.beau-jangles.com
In Dubai where has been raining !!!

I use Zam to polish my silver items up ...but I now have quite a
lot of "ZAM bits" that fly off when I charge my felt. Is there any
way of re using these bits (e.g. reconstituting them into another
block rather than small bits) or reducing the amount of bits that
fly off when I charge my felt ... 

Paul, while you might get contrary advise on this, my advise is to
forget the crumbs. You will pick up contamination by trying to
recycle them and the cost in time required to recycle, if it could
be done, and the potential damage to a piece you are polishing, is
just not worth it. I am curious though as to the bits you are
talking about. I use Zam all the time, both on my flex shaft and on
my big bench polish lathe. The only thing I can think that might be
causing you to loose material, is that you are exposing too much of
the zam, and are overcharging the felt… I only peal back just
enough paper on the zam to allow the center of the stick to contact
the buff. Also, a one second kiss with the stick is enough polish to
do most jobs. Too much polish on the wheel will cause grooving and
undercutting, IE orange peel.

Don

 Am I correct in thinking that if I substitute high melting point
silver solder for enamel melting point silver solder that the
joint will be even stronger and less liable to discolour as the
Silver content in the solder will be higher ? and if I adopt this
approach are there any down sides to it, other than it needs
greater heat control when soldering. 

You would need to specify the particular alloys you mean when you
say “high MP Ag solder” and “enamel MP Ag solder” Paul.

If you mean the generally used “hard” Ag solder ( 75/22/3 Ag/Cu/Zn )
and eutectic Ag solders ( 72/28 Ag/Cu ) respectively and intend to
enamel over the joint the answer is no.

The 72/28 Ag/Cu eutectic alloy is the best choice for use with 925
Ag ( I’m assuming that’s what you’re intending to enamel - if you
were using 999 silver you could solder it with ordinary Sterling )
because it:

1/ contains no Zn which is just a bloody nuisance when enamelling

2/ melts at a precise temperature - 778 deg C

3/ flows beautifully & leaves no cap - essentially becomes
indistinguishable from the Sterling base and would appear not reflow
on subsequent normal firings.

Certainly it’s possible to enamel successfuly over this material.
Use the smallest amount necessary to effect the join and depletion
enrich edequately after soldering.

The “hard” 75/22/3 alloy has a softening point ( about 740.5 deg C )
and flow point (787 deg C ) not a melting point so is consequently
still “slushy” below the “setting” point of most enamels - they crack
and/or break away.

In cooling and hardening the enamels can also deform the
still-gluggy joint.

Almost the same things can be said of the stuff I’ve touted for most
of my enamelling life - the 80/16/4 alloy ( SP 721 deg C, FP 810 deg
C ) - the so-called “IT enamelling Ag solder”. Until a couple of
years ago I still persevered with this stuff in spite of the fact
that I could only make it work in a so-so fashion.

I knew that silver-filigree makers had used the eutectic alloy
successfully for a thousand years (bit of artistic hyperbole here )
and Eastern European enamellers had borrowed their materials and
techniques to make their stunning plique-a-jour but I thought I knew
better. I looked at the Flow Points of the various alloys and thought
that higher must naturally be better. I was ignorant of the
metallurgy involved and suffered the consequences of my
pig-headedness .

cheers
Al Heywood

Paul,

I work with both enamel and sterling silver and the highest melting
point solder available is IT solder. It has the largest percentage
of silver in it. Your seams need to be extremely accurate and you
will most likely always see the seam, but with IT (and you must be
careful not to melt your piece) the seam is less noticeable. I use
hard solder (a lower melting point than IT) on my sterling and on my
fine silver items.

Jennifer Friedman

enameling over a fine silver base , you should use sterling as the
solder Belinda, if you were using 999 silver you could solder it
with ordinary Sterling was what I said - it contains only copper and
silver. and if you are enameling sterling silver base, you should
use the 72/28 ag/cu solder?

yup.
allan