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Enamelling on hollow objects


#1

Hello my name is phil I am currently trying to enamel onto fine
silver hollow egg shaped pendants (later I will be doing gold too) .
I am having problems with the enamel chipping off and assume i have
to counter enamel , the eggs are made of two halves soldered together
, some are to be stone set as well . obviously the counter enamelling
will have to done before they are soldered together as there is no
way to get it in there after , I have made master pattern wall
thickness about 1.3 mm, eggs are about 15 to 20 mm high . Do i have
to counter enamel entire inside of egg or just opposite where enamel
will be on outside as I would rather not have to put counter enamel
under where stones will be set, will I have the same problems with
18ct gold as ive had with silver or does gold have a different
contraction and expansion coefficience to fine silver. Will the
counter enamel be damaged when I solder two halves together and how
many layers of counter enamel will I have to apply. Also once counter
enamelling is done and two halves are soldered together is there
anything I have to be careful of when pickling and applying final
enamel layers on outside. thank you for any help you can give me .Phil.


#2
Hello my name is phil I am currently trying to enamel onto fine
silver hollow egg shaped pendants.  

If you try to solder after counter enameling, you risk having the
enamel crack and chip off; all soldering should be done before
enameling (IT or hard solder only). I have done hollow forms and have
a few suggestions. Texture the inside of the hollow form (texture helps
keep the enamel in place on curved areas), shape, then solder. You
need to have a small hole somewhere on the piece so that it won’t
explode. If you are putting stones on, then you can put the hole under
the bezel where the stone will later cover the hole. Use the hole to
inject wet counter enamel (consistency of thick cream) with a syringe,
roll it all around, let dry. Make sure the hole is still open and fire.
When you pickle, stop up the hole with toothpicks or wooden skewer
tips. Apply enamel and fire. If you get cracking on the outside, you
need more counter enamel and can inject more through the hole. I
haven’t enameled gold hollow forms, so can’t answer that one.

Donna in VA, leaving for the Enamelist Conference soon


#3

hello everyone this orchid site is the best. A while back i asked
about enameling on hollow 18ct and fine silver objects but didnt
really get the help i needed . i have made a selection of patterns
of faberge egg style pendants about 25mm high and 20mm wide each is
cast in 2 pieces with the seem running vertically. All have engraved
patterns on them and holes drilled for pave setting of diamonds. the
wall thickness is about 1.3mm .I can email pictures if necessary. I
am trying to teach myself enameling as in New Zealand there is only
one other person doing enameling and apparently they are not
interested in teaching anybody. i have had problems with enamel
pinging off . Am i supposed to counter enamel and if so how can this
be done as there is no way of getting enamel on inside once all
soldering is done. Does the enamel come under more tension the more
layers and fireings you do and if so how many times can i get away
with before i will have problems. One piece i have just finished
making is a fine silver egg with pearced out 18ct yellow gold leaves
and butterflys soldered on to be enamelled up to the level of the
gold . can anyone give me few pointers before i start enameling it.
i have not yet tried to enamel an all gold egg as im trying to make
the trial proccess as cheap as i can. how did those clever dudes at
faberge do it ??? please help


#4

Here is another site that might answer your question.
www.thompsonenamel.com Marilyn Smith


#5

I will readily admit to not having done anything of the magnitude
you are talking about but I can answer a couple of your questions.

Typically you don’t need to enamel the inside of such an object.
Because it provides it’s own tension by being enclosed and not flat
you don’t have the warping problem you do with a flat piece. Same as
with a bowl.

As far as colors go. Many colors are hard to work with on Silver,
please test them in the combinations you are planning to use first.
Many of them turn yellow…some colors can not take repeated firings.
Especially those in the red range. This will vary based on the
specific color and “brand” of enamel used. The leaded european types
tend to hold up a little better.

Last, I am assuming you soldered with IT solder. Even with high temp
solders there can be a tendancy for the solder to flow up through the
enamel or show beneath transparents. This tends to increase with
repeated firings.

What a job to pick for a beginner! Good luck!

Karen


#6

I just started enameling and doing hollow forms, I will ask my
instuctor. Just a thought, try your enamel supply house. the one
recomended in the US is thompson enamel. Apparently there is liquid
counter enamel. I was also told about something called “it” silver
soder that melts at a temperature that is higher than hard, and
melts at a tempurature higher than enamel. jj

There is also something called the international enamelers guild try them


#7

Hi Phil, I haven’t done too many hollow objects before, so therefore
I can just throw out a couple possible reasons for your enamel to
ping off (pictures may help). 1) Not having a ruler w/me regarding
what gauge 1.3 mm. is, I’m guessing, anything under 18 to 20 gauge
could be too thin for the size you’re doing, particularily since you
can’t counterenamel. 2) Your piece isn’t clean enough, you can have
absolutely no finger oils on your piece before you apply the enamel.
I wash all of my pieces w/cleanser, or diluted ammonia water prior to
enameling, and diluted ammonia during different firings if I’ve
handled it. 3) I imagine you’re wet packing w/enamel mixed w/water,
and a drop of klyefire, or some binder. Are you completely drying
the piece before firing? Any moisture in the enamels when placed in
the kiln can cause the enamel to pop off. I tend to dry my pieces on
top of the kiln while working on the next one. If you’re sifting
onto some binder, it would still be the same issue, not dry. I’m sure
there are areas I haven’t covered, but perhaps this will give you a
start. If you’d like to send a picture perhaps I can help more, I
live in the boonies and am primarily self-taught so I can relate. :slight_smile:
Good luck!!!

Lisa


#8

Phil I’ve done enameling on hollow forms. You need to leave a small
hole (it can be tiny) in a closed form. If the form is entirely
closed you risk it exploding at high enameling temperatures. If you
are doing pave on a piece, you could drill a minute hole under where
a diamond will be set. Your metal should be thick enough to work but
your solder seam could be problematic under transparent enamel
because the solder line could show. Any extra solder on the seam
needs to be cleaned off. All soldering should be done with IT solder,
although if you have enough experience with soldering and enamels,
you can get away with hard solder. The fact that you have a pattern
engraved on the metal will help prevent chipping off. Enamel normally
needs to be on both sides of a form to equal tensions. I did one piece
with cloisonne and no counter enamel and had no chipping but have
seen chipping and cracking happen in bead forms if the enamel is not
applied evenly. If you do put a tiny hole in your egg, you can use a
hypodermic needle to inject some liquid counter enamel into the egg,
roll it around, open the hole if it closes and fire.

How are you supporting the hollow form in the kiln so as not to
damage the enamel?

You could e-mail me off-list if you want more explicit

Donna in VA (USA)


#9

As I understand it, the object is commercially made but please
correct me if I’m wrong. If it’s cast, there should be no solder to
worry about. Am I correct that it is made to be enameled? In that
case, it should be heavy enough to withstand the firing temperatures
etc. I have not done a lot of enameling but here are my thoughts.
Thin coats are better than heavy. Enamels have different expansion
rates. Are you using enamels that have the same rate? Allow to cool
slowly.

Marilyn Smith