Hi everybody! Foolish though I may be, for my first year
chainmaking class I am attempting enamelled flat links with my
torch. The background, unfortunately, is in opaque white enamel,
and I keep getting these darn burned edges on them! Brown to
black all around the edge, it looks terrible.
I was wondering if maybe I was using the wrong kind of flame to
heat the piece from the back… short reducing? Short oxidizing?
Any tips to avoid the burned edge? I need to fire the piece at
least four times – first layer background, second layer
background, design layer and flash – so I’m finding it almost
unavoidable. Any help would be much appreciated! I’m the first
to admit I don’t really know what I’m doing, I’ve only read
about it… -Kieran
You can enamel with a torch? I was only taught using a kiln!
How do you enamel with a torch? I have dozens of containers of
enamel laying around that I can’t use because I haven’t access to
a kiln - this could be just what I need to learn to use up all
that supply
Dear Kieran, Try filing a beveled edge around each of your links
before you start enameling. After firing, file or sand it it
clean again, carefully. When all firing is done, sand and
burnish the beveled edge. Learned this from Dee Fontans at a
great workshop. Pat in Central PA
I was wondering if maybe I was using the wrong kind of
flame to heat the piece from the back... short reducing? Short
oxidizing? Any tips to avoid the burned edge?
Whilst I don’t do enamelling, I have done quite a bit of
glassblowing in the past, from scientific glassware to neon tube
inserts, to glass animals. I mention this because the enamels
are of course, finely powdered glasses. One needs a special
torch for using the low softening temperature glasses as they
often contain lead or cadmium or at least, they used to. Any
kind of reducing flame will cause some of the glasses to blacken
or discolour because of their heavy metal content. I had to buy
a special torch which gave a highly oxidising flame as my normal
torch blackened the white, turquoise, orange, red, some greens,
etc. But I did find that if I used the very tip of a flame with
an ordinary compressed air/gas torch I could usually restore the
original colours. Cheers now,
Hi JugularGirl, If you have to fire the units outside a kiln,
try putting them on a piece of coarse mesh and use a soft, fluffy
flame from underneath to warm everything to the temperature you
need. HTH, Rex from Oz
Hi Perhaps the following will be helpful. I don’t do enamelling
but work with lampwork mainly glass beads. I don’t know what
type of fuel you are using. Acetylene gas will cause your glass
to turn black or dark. Also , if you put your glass into the low
part of the flame it will darken the glass. The more oxygen you
use in the flame the more of a reducing effect you will get. If
your flame is yellow it has a lot of oxygen and therefore
reducing effect. Good luck! Paul
You can enamel with a torch? I was only taught using a kiln!
Kirsten,
I make enamel beads with a torch every day. You can check out
the results at http://www.pinzart.com I don’t know if this is what
you had in mind. Let me know if you want more info on this
technique. It’s relatively simple.
Also , if you put your glass into the low part of the flame
it will darken the glass. The more oxygen you use in the flame
the more of a reducing effect you will get. If your flame is
yellow it has a lot of oxygen and therefore reducing effect.
I think you’ve got that backwards. Oxygen is oxidizing,
unburned fuel is reducing. The more oxygen there is, the more
oxidizing the flame. That’s a sharper, hissing flame. The
yellow is indeed reducing, but from an excess of carbon or fuel,
or shortage of oxygen. That carbon/fuel can remove oxygen from
metal oxides, thus reducing them back to metalic form. With a
normal flame, the part closest to the torch, the light colored
little cone, is often reducing because there is still unburned
fuel to scavenge oxygen. Farther away, where all fuel is burnt,
there is only excess oxygen, so the flame is oxidizing. In a
nuetral flame, oxygen from the mix is balance with the fuel,
leaving no excess of either. But atmosphereic oxygen, carried
into the flame, makes the end portion of such flames oxidizing
even so. Oxidizing flames blacken the metal, while reducing
flames clean metal but can also reduce oxides in the enamel,
which discolors them instead of the metal… The usual choice
is an oxidizing atmosphere, which is kinder to the enamels, and
oxides on the metal can be pickled off or abraded off later,
while reduced/discololored enamels are harder to correct… But
it’s even more complex that that too, since when the metal
oxidizes, those oxides just adjacent to the molten enamel are
partly soluable in that enamel, so the boundary at the edge of
the enamel can discolor from absorbing those metal oxides, in
addition to it being the part most likely to overheat, which also
degrades the enamel…
Acetylene gas will cause your glass to turn black or dark.
Also, if you put your glass into the low part of the flame it
will darken the glass. The more oxygen you use in the flame the
more of a reducing effect you will get. If your flame is yellow
it has a lot of oxygen and therefore reducing effect.
Not to be argumentative Paul, but some of this is
incorrect. I am a long-time beadmaker and have done some
torch-enameling. It is possible to torch-enamel using acetylene
(I learned from Deborah Lozier using acetylene and air). It’s
important to heat your piece from below until completely fused
and "orange-peeley. You can heat it directly from above at that
point, but you don’t want your enamel in the cone of the flame.
Also, some colors will turn dark or gray when heated directly
from above. Opaques are particularly vulnerable, as are pinks,
reds, oranges, yellows. It is untrue that “the more oxygen you
use in the flame the more reducing effect you will get”. More
oxygen makes a more oxidizing flame. More fuel makes a reducing
flame. The reason glasses turn black or gray in a torch is
because of too little oxygen, not too much. They are being
reduced, not oxidized. (This is why kiln-fired enamels don’t
discolor this way: the kiln is a completely oxidizing
atmosphere.) Opacifiers and colors containing gold or cadmium
(the reds, some pinks, etc.) are especially vulnerable to
reduction. The reduced gold, cadmium or opal colors are generally
dark gray or steel blue-gray. Acetylene is an especially “dirty”
fuel compared to propane or natural gas. It has more carbon,
which provides a more reducing atmosphere and thus more
potential discoloration. If your flame is yellow, it doesn’t have
a lot of oxygen, it has a lot of fuel. Oxidizing flames are
bluer.
To those who wish to try torch-enameling, look at the work of
Deborah Lozier. It’s all done with a torch. It can be done!
For the record, I use an inexpensive bernzomatic torch and
straight propane. I heat the enamel directly and I have almost no
problem with discoloration. I imagine this is because I’m using a
cooler flame. I know this technique works great for beadmaking.
I have no idea how it would work with other types of enameling.
The process is fairly simple. I cut copper tubing into small
lengths (1/2" to 3/4") to serve as my “bead hole”. Place the
tubing on a bead mandrel (available from Thompson Enamel). My
torch is stationary, attached to my bench, so I have my hands
free. I heat the tubing in the flame until it’s glowing. Then I
roll it in 80 mesh enamel. I heat that to the orange peel stage
and then repeat a couple of times to get a good coat of it on.
Then I switch to 6/20 mesh enamel. This is much coarser and will
build up a good size bead quickly. When the bead is done and has
cooled to the point of having a hard shell, I push it off the
mandrel with a pair of pliers into a crockpot full of hot
vermiculite. You have to be a little careful with this part. If
you drop it into the vermiculite too soon, the vermiculite will
stick to the bead, but if you wait too long the bead will cool
too quickly and will crack. It’s not split second timing, but it
does take a little practice.
For the record, I use an inexpensive bernzomatic torch and
straight propane. I heat the enamel directly and I have almost
no problem with discoloration. I imagine this is because I'm
using a cooler flame. I know this technique works great for
beadmaking. I have no idea how it would work with other types
of enameling.
Hi! This is interesting. The glassbead sources always emphasis
a specific type of MAPP gas torch. It is hotter, and it adjusts
itself to an oxidising flame (more air to fuel ratio). I have
some bullseye rods. Do you know of them, have you worked with
them, or with frit (finely ground glass) or do you use strictly
enamal - type prepared glass? I saw your web pictures, they were
very pretty, and they looked like tremendous fun! If this is too
glassworky for Orchid, email me off-list, please.
I’m the first