Enameling Repair

Hi All;

I have an account who specializes in “estate” jewelry who keeps
pestering me to repair enamel pieces (he’s a cheapskate and doesn’t
want to send it to the specialists). I’ve told him I’m no expert at
enameling. Although I often use enamels (yes, vitreous, fired in a
kiln, etc.) in my work, I keep it pretty simple. The articles in
question are usually transparent enamels over engine cut patterns
(guilloche?). Should I attempt to match the enamel, fill and fire,
stone and polish, or is there a good way to remove all the old
damaged enamel? I’ve heard the ultraviolet cured resins are a
possibility, but I’m not ready to pony up for that setup just yet.
I’ve tried heating and quenching in water, but the stuff really
hangs in there. If I go at it with a hammer and tool, I’m likely to
damage the pattern underneath. Any of you experienced in this kind
of work?

David L. Huffman

Hi David,

    I have an account who specializes in "estate" jewelry who
keeps pestering me to repair enamel pieces. The articles in
question are usually transparent enamels over engine cut patterns
(guilloche?). 

I’m guessing that they usually have only one color on them? And that
the enamel is a fairly thin layer?

    Should I attempt to match the enamel, fill and fire, stone and
polish, 

You could but it might be hard to match the exact color, thickness,
transparency, firing temperature, C.O.E. etc… of the enamel left
on the damaged piece without knowing the exact type of enamel
previously used, weather it was leaded or lead free, the color and
company that made the enamel. And if it didn’t match really well you
would notice the repaired patch. Also the stoning, and polishing may
have a different texture depending on the hardness of the previous
enamel, and the new enamel fill. If you knew the exact enamel used
on the object it might work to go about it that way.

or is there a good way to remove all the old damaged enamel? 

Possibly, heating and quenching the piece in cold water (as you
mentioned) can be a way to remove some of the enamel but it might
not all come off. There are chemicals that some enamelists use to
remove enamel, but these are potentially very dangerous and require
appropriate safety precautions. You may also have to consider what
surface re-preparation you might have to do to the metal before you
could re-enamel the piece, depending on what the base metal is, and
how it was originally treated to accept the enamel when it was made.
Here’s a link to an article which discusses enamel removal, it also
mentions the chemicals some enamelists use, and VERY important notes
about safety in the use of those chemicals:

heywoodenamels.com - Diese Website steht zum Verkauf! - Informationen zum Thema heywoodenamels. d.html

Any of you experienced in this kind of work? 

Though I’ve enameled for many years I’m not very experienced in
repairs, it would be very hard for me to suggest the best approach
for you to take in the removal of and restoration of enamel on the
articles you’ve mentioned, especially without being able to see each
object, and know it’s specific history.

I've heard the ultraviolet cured resins are a possibility, but I'm
not ready to pony up for that setup just yet. 

Yes there are several non-enamel materials that can be used to fill
a damaged area on an enameled object, and the ultraviolet cured
materials are one choice. I believe that using those type materials
would be considered more a “repair” than a “restoration” of the
enameled object, and may effect the value of the object since it
would not be the original type of vitreous enamel material the
“estate” piece was made with. There are several factors to consider
when deciding how to repair or restore an “estate” piece, and which
process to choose, vitreous enamel or other synthetic resins and
composites. Both have their place and uses depending on all the
contributing factors in the repair.

I was hoping that you might get some more directly useful answers
from other Orchadians with more experience in enamel repairs than I
have. However since you haven’t had any other replies I will try to
be of some help by including links with on them, as well
as suggesting that you email Allan Heywood enamelist / enamel
restoration expert, at eNAMEL Online Newsletter :
enews@heywoodenamels.com or info@heywoodenamels.com

Or email / phone Bill Helwig or Tom Ellis, enamelists at Thompson
Enamel and Glass On Metal magazine:
http://www.glass-onmetal.com/ask_the_experts/index.htm Thompson
Enamel, Inc. 650 Colfax Ave. Bellevue, KY 41073 (859) 291-3800
http://www.thompsonenamel.com

All of them are very knowledgeable and you could ask them about some
common ways to go about the task you are considering undertaking and
where to find literature on the process.

It can be a difficult and complicated process to remove and restore
enamel to “estate” objects. I do not do any repairs of other
enamelists works… as there are many variables and a good number of
things that can go wrong. I always recommend an enamel restoration
specialist such as Allan Heywood to the many people who inquire with
me about an enamel repair. http://heywoodenamels.com

 The articles in question are usually transparent enamels over
engine cut patterns (guilloche?). I've tried heating and quenching
in water, but the stuff really hangs in there. If I go at it with a
hammer and tool, I'm likely to damage the pattern underneath. 

Yep vitreous enamel is stubborn and can be hard to remove! Ice cold
water may work a bit better than room temperature. You are certianly
right in your thinking that it would be unwise to take a hammer to
the enamel if you want to remove it!

While a lot of it will come off, if it’s vitreous enamel, even after
hammering the heck out of it some amount of enamel will still
probably cling to the metal surface, and you will VERY likely damage
the pattern on the base metal as you correctly surmised and
mentioned in your post… I’ve damaged metal patterns in the past
trying to remove enamel from my own piece I was working on, well
maybe I really just hit it with the hammer to release some
frustration over a mistake I’d made in the enamel.

Another place you might look for is on a web page called
“Useful Stuff” loads of articles linked there:

I guess the other problem in taking on an enamel repair is as you
get deeper and deeper into either the filling or removal of the
enamel and repair or restoration of the object… if you have any
set backs in the process, how much time will it take you to get a
good result, and what will you have to charge in order to make it
worth YOUR while?! In the end sometimes it is cheaper to pay an
expert, and be done with it, rather than you having to learn on the
piece and spend more time than you are getting paid for.

I wish you the best of luck with the piece / pieces.
Sharon Scalise
Ornamental Creations
@Ornamental_Creations
http://users.netconnect.com.au/~sscalise/

Hi David - I have occasionally repaired enamel but it is the sort of
thing that most enamellists run a mile from as it can be fraught
with difficulties. However, it sounds as if the repairs you are
talking about are the tops from perfume bottles and the like where
the enamel piece has been set like a stone. If this is the case then
they can be renewed by unsetting the enamel. To remove all the
enamel I use Matting Salts. Have no idea what the chemical formula
is, but it will slowly etch the glass away over a period of 3-7 days
leaving the metal completely clean. (For faster removal one can use
hydrofluoric acid but it is really evil stuff & personally I won’t
keep it in my studio.) Trying to repair part of the enamel is
extremely difficult as it is virtually impossible to get an exact
colour match. If the enamel just has hairline cracks you could try
just reheating it to see if they close up. Hope this helps.

Deborah Miller
www.djm-jewellery.co.uk