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Enamel flaws


#1

I am having problems with pits and bubbles in my enamel. Does
anybody know where the pits and bubbles come from?

Fawniel Henshaw


#2

Hello Fawniel,

Regarding your question about the source of pits and bubbles in your
enamels.

Some possible sources of your problem aRe: a contaminated surface,
contaminated or “old” enamel, the enamel was wet when put in the kiln,
the enamel was too thickly applied.

I believe that we who enamel copper with transparent enamels have a
much tougher time than those enamelling on fine silver. In our case we
need to add just enough enamel to cover the surface of the copper so
that fire scale does not form, but not so thickly that it traps
pockets of air. Thin layers are best, but not too thin.

Hope this helps,

David


#3

Pits and bubbles come from a variety of problems.

Dirt in the air or around your studio landing on your metal or enamels
prior to firing causes pits. I have almost stopped using scalex for
this reason.

Not cleaning exposed copper where firescale has formed prior to
firing, it will ping off and land in the enamel causing pitting.

A foreign substance in your enamel.

A dirty surface on your enamel.

Too hot of a firing can cause bubbles along with not letting your
binding agent dry completly beforehand.

Many other things can cause these problems as well. You may want to
hit the library and check out a couple of books. Is there a specific
time these problems are happening that couldn’t be caused by the
above?

Karen


#4

Pits in the enamel are the result of air bubbles. I have found that
pits tend to occur when the layers of enamel are applied too thickly.
It is better to apply more layers that are thin. If pits are present
after stoning and sanding my enamels, I fill the pits, refire and
sand again. I have found that I can keep pits to a minimum by keeping
the layers even and very thin.

–Vicki Embrey


#5

Are you wet packing??? If so, you may not be completely drying your
enamels before fireing. If there is any moisture present when you
put them in the kiln, there will be little explosions of steam caused
by the evaporation of the water, and this will cause pitting and
bubbles. Another possibility, if you are wet packing and using a
binder, such as gum Tragacanth, or klyr fire—if the solution is too
thick it prevents good packing down of the enamel grains, and there
may be small air pockets. Try diluting you binder. I use a heat lamp
to dry my enamels before inserting them in the kiln,
therefore assuring that all mosture has evaporated.
Hope this helps—Alma


#6
I am having problems with pits and bubbles in my enamel. 

Hallo Fawniel, There are so many reasons for pits and bubbles. -Did you
clean your metal before enameling? First thing to do before laying on
the enamel (wet or dry) is cleaning the surface, it should be as
clean as when you should use adhesives. No grease, dust or even any
cleaningliquid or sparex should stay on it. -When the pits are black,
it could be oxidizing copper flying around in your working area,
fallen into the the drying enamel. -When it is just a pit, it could be
that your enamel isn’t melted totally, it is just the 'orange-peel’
stadium. A bit longer or a bit hotter burning will give a perfect
surface. Every enamel has got its own melting point, and the fist
burnings don’t have to be perfect, you finish the piece by melting all
to the perfect temperature. -Of course it could be caused by a short
of enamel, than there is no enamel underneith the pit. -Some other
reasons for your enamel surface to look uneven: dust fallen on the
drying enamel (I hate cleaning, but your working place should be as
dustfree as possible. Only don’t sweep away the dust in advantage of
enameling, because then the dust will come back down all day. When I
have to go on with a project and there is a lot of dust I leave as
silent as possible or I clean it wet and take care nothing is
disturbed before I can wet it. -Your enamel can be dirty, wash it out
before you use it.

Bubbles can be the resuld of still wet enamel, drying in your kiln
while burning the enamel and cousing a bubble in the melted enamel.
Your enamel must be really dry before putting it in the kiln, better
wait to long than take a risk. Sometimes I wait a night to be sure,
when the project is big and the air not so dry (I am dutch and here in
Holland the air is often quit damp).

When you do a lot of enameling there are quit a lot of good books to
buy. I use one very often, new and american: ‘enamels, enameling,
enamelists’ from Glenice Lesley Matthews, 1984, Chilton Book Company,
Pennsylvania 19089, isbn 0-8019-7285-X. It helped me to find my own
way to enamel and gives answers to almost any question.

I hope I could help you a bit, ask again when it is not clear,

Marleen B.Berg.


#7
     I am having problems with pits and bubbles in my enamel. Using
a lot of glue ( klyrfire) , or using it too thick, 

can leave enamel with bubbles. Take a scribe and open the hole and
drop a bit of water with some klyrfire and touch up the hole. Refire.

Louise
@lgillin1


#8
    I am having problems with pits and bubbles in my enamel.  Does
anybody know where the pits and bubbles come from? 

Fawniel, Usually this is caused from a contamination of the surface of
the metal or the enamel. Make sure that your metal is clean, no
grease, no residue of pickle or cleaning solution. Make sure the
enamel is clean. Are you working with the enamel wet or dry? If you
are dry sifting your enamel onto the metal, make sure the adhesive
you are using is free of contaminants. I use distilled water when wet
packing enamels. What type of enamel are you using? Leaded or
unleaded. How old is the enamel? Are you washing your enamel before
you use it? Is your work surface free of contaminants?

There is hope for the piece if you want to try and save it. Use a
small diamond impregnated bit and break the bubbles and clean them out
as well as the pits. (Use safety glasses and a mask) I dip the tip of
the bit continuously in water to avoid too much heat or friction.
Take the enamel piece and put it in pickle to clean. Remove from
pickle and rinse well. Then using a glass brush with a mixture of
ammonia, detergent and water clean well. Rinse very well then let the
enamel piece dry. When dry apply dry enamel (do not use binder)
filling the craters and pits just slightly above the top of the crater
or pit. Then refire. Sometimes you might need to add a little more
enamel and then do a second firing. You be the judge. Hope this
helps. Happy Enameling! Linda Crawford Linda Crawford Designs Willits, CA
http://www.lindacrawforddesigns.com

“Experience is something you don’t get until just after you need it.”