When soldering pieces of tubing to a piece of jewelry to make
knuckles to form a hinge, place a piece of pencil lead (graphite)
through the tubing. This will keep the tubing lined up while
soldering. The graphite will withstand the temperature for the
solder to flow and you can easily remove it when cool. Various
diameters of pencil lead for mechanical pencils can be purchased
from office supply stores. (A pencil can also be used for a solder
pick) Brad Simon CMBJ
Here’s another idea for holding hinge pieces in line for soldering
if you don’t have graphite pencil lead on hand…I save old drill
bits and coat them with white out then use them to hold the hinge
pieces in line…works great.
A school mate of mine had a pencil explode while he was using it for
soldering. Graphite absorbs heat really well. As the heat travels
up the rod it can reach temperatures that can cause combustion to
occur. Where the wood and graphite come into contact a build up of
gas can cause the pencil to explode rather violently. My school
mate was lucky he didn’t injure his eye. Perhaps he was being
careless, but, I have never known a commercially available soldering
pik to explode.
The are many things that pencils are useful for, but, I can’t say
that this is one of them.
Larry
Larry, This trick uses lead–graphite-- from MECHANICAL pencils and
has no wood component at all. This does, in my opinion, work well.
You can also use an old drill bit that has been repeatedly heated and
not cleaned. This sooted surface keeps solder from flowing onto this
temporary hinge pin and doesn’t involve the use of white out or ocher
which can dirty up the seam that you WANT to flow and can also act as
a spacer in your hinge lug/knuckle causing misalignment. also the
variety of drill bit sizes is much more extensive than pencil leads.
Good luck,
Andy Cooperman
Larry, I have been using a pencil for soldering for almost 15 years,
and I never had one explode. I have had both steel and titanium
picks ignite when overheated.
I suppose that it is possible for graphite to explode, but I would
imagine that it would have to be severely overheated. I use a
graphite rod for stirring molten metal as well, and never had a
problem. I know that the type of high heat and oxidizing flame used
to weld platinum would probably be enough to cause a graphite rod to
lose it, but soldering platinum with a graphite rod is not a sound
idea anyway.
You mentioned that this was a schoolmate of yours. I have seen
students do things that I would have never thought possible. I once
saw a student set fire to their bench while soldering…and I mean
completely on fire! 
I guess it should be mentioned that one
must remove the wood from around the lead of a pencil for at least
1" from the tip, and of course, never use a mechanical pencil. I
have had .05 leads fracture while soldering hinges, but this has
only created a minor inconvenience, never a hazard. I should also
mention that I NEVER work at the bench without safety glasses, and I
wear a flameproof apron. I am very experienced and very careful, but
shit happens (see Murphy’s Law, particularly the section on hot
objects that fall into your lap).
I have had more problems using steel drill bits, saw blades, paper
clips, and other metallic devices…they do burn, and too often
became an unintentional part of the hinge. I still feel safer using
pencil leads.
Happy soldering!
Doug Zaruba
Here's another idea for holding hinge pieces in line for soldering if you don't have graphite pencil lead on hand....I save old drill bits and coat them with white out then use them to hold the hinge pieces in line...works great.
And if you don’t happen to have “White-Out” handy, simply heat the
old drill bit up to oxidize it - then coat it in mineral oil…
Brian P. Marshall
Stockton Jewelry Arts School
704-708 West Swain Rd.
Stockton, CA 95207
209-477-6731 Office/Fax
209-477-6535 Workshop/Classrooms
The issue of the exploding pencil may be linked to an observation
that I have made regarding the composition of pencil leads. For many
years I have been using graphite pencil leads to keep openings in
casting waxes from filling…I.E. When casting hinges for
bracelets I would maintain the opening for the pin by plugging it
with a pencil lead. After casting the graphite could readily be
removed leaving a perfect opening. In recent years I have discovered
that not all pencil leads are graphite and would not work in the
mentioned application…therefore, it is entirely possible that
pencil leads are now made with a substance which is temperature
sensitive and could explode…quien sabe ?
Ron at Mills Gem, Los Osos, CA.
I have had more problems using steel drill bits, saw blades, paper clips, and other metallic devices...they do burn, and too often became an unintentional part of the hinge. I still feel safer using pencil leads.
I was taught to use brass rods slightly smaller than the ID of the
hinge tube. They need to be oxidized or painted with ochre and dried
before inserting.
Also, I was taught to use paste solder to tac the sections in place
- when sure they are right, then remove the rod, separate the two
sides of the hinge, and solder the sections in place permanently - it
goes without saying to pay attention that no solder gets inside the
hinge and if it does, you’ll have to file it out.so your rivet will
fit.
Kay
I doubt even plat heats would break down graphite. As a glass blower
I commonly stick graphite tools into a 4800 F flame to no ill effect,
I even dunk them in water to keep it all cool, no prob. I also use
pencils for doing detail work, never had a problem with it exploding,
but I do see how it would be possible. Also, as a student, I assure
you, if something can’t be broken or otherwise destroyed, it can be
by a student. =) -Doug
You mentioned that this was a schoolmate of yours. I have seen students do things that I would have never thought possible. I once saw a student set fire to their bench while soldering...and I mean completely on fire! :-)
This is a really good point, and we have to remember that there are
a lot of novice jewelers who read these threads and may need more
than just a cursory explanation of a technique to stay out of
trouble. Your advice to carve back at least one inch from the end
is excellent. I didn’t mean to say that graphite could explode but
the gas trapped between the wood and the graphite.
I sometimes don’t respond to posts I read because there isn’t enough
time in my day to explain all the details that could get a novice in
trouble. All the dangers should be explained in order to keep
people from getting hurt.
Larry
Someone may have brought this up but I’ll mention it again in that
case. Pencil “lead” is not just Graphite. The old traditional stuff
is a clay plus graphite. This should work ok with heat. A lot of
pencil “lead” now is graphite plus an organic polymer (plastic) The
mini leads for automatic pencils are this material which will account
of the breakdown “explosions ?”. Some wood covered pencils will also
contain this stuff.
Graphite stirring rods should be just graphite.
Jesse
Well, this makes since, there are pencils that use a
plastic/graphite that’s much more resistant to breakage than normal
pencil graphite. You can usually tell because it’s in a plastic
pencil instead of wood. Also, the very small mechanical pencil leads
are often made of a similar polymer/graphite combo to prevent
breaking (I’m looking at a box now, touting "Super Strong Polymer,
Will Not Break Like Other Brands.) Your best bet is probably to go to
an art or drafting store and get Drafting pencil leads, they’re 100%
graphite (unless they say otherwise, some also use polymer graphite)
and come in a range of larger diameters from 1-3mm or so. I’ve used
these as both solder picks, and Glass working tools with no problems.
As for exploding lead, the gasses made by heating the plastic binding
stuff in these types of graphite could catch fire, or build up
pressure enough to make a pencil explode. Just make sure your pencil
uses real lead… kinda hard to tell, but the plastic leads will look
smoother and draw a lighter line than real graphite.
my 2=A2
-Doug
Maybe this is old hat to a lot of you, but i was taught to use a
nail coated with ochre which is applied to the nail, heated and
burned on. then it is inserted into the hinges to hold them
together. Works fine for me and I do a lot of hinges. i just use
a nail close to the inside diameter of the hinges so that there is
no slippage. One could also use pieces of brass or
copper wire of a suitable diameter. Alma
The tip to use “pencil lead” to align hinge parts is a good one, and
worth repeating from time to time. Be aware though that many modern
pencils have a significant amount of polymer incorporated as a binder
(some replacement leads for mechanical pencils even mention "polymer"
on the label). Needless to say these ones don’t stand up to heating.
Older leads are (were?) graphite with clay added to increase
harness.
Kevin (NW England, UK)
i was taught to use a nail coated with ochre which is applied to the nail, heated and burned on. then it is inserted into the hinges to hold them together.
I was going to butt out of this discussion, but it keeps going and
no one has mentioned my favorite, so, so much for self control. I use
titanium wire. Its limit is in variety of available sizes (and I’ve
never tried drawing it down) but ti will not solder, even if you
wanted it to, and it doesn’t act as a heat sink. It is very strong
and fairly rigid, and can easily be removed after soldering, to be
reused later. HTH, --Noel