written by Henry Higgins
artillery projectile a relic hunter finds is really special.
That portion of the world who are non-collectors only see a
big piece of dirty and rusty iron, but to the relic hunter
who just spent a hard time digging it out of tree roots,
hard clay, or a swampy bog, itís a prize to be treasured and
Now comes the
inevitable question - how do I clean this piece of history?
And how do I preserve the iron and stop the deterioration?
When I first
began relic hunting in 1963, the problem of cleaning and
preserving projectiles usually boiled down to washing as
much mud as possible off and wire brushing the projectile
with some sort of rust remover. Then a heavy coating of
marine varnish was applied. Of course, all this did was
force moisture into the iron and cause metal cancer to
develop. (Metal cancer is caused by the breakdown of iron
into a powdery black material which, over a period of time,
results in large pieces of iron falling off the exterior of
the projectile.) Many projectiles treated this way during
the 60's and 70's can be recognized today by large divots or
deep cracks all over the surface.
After a few
years of trying different methods of preservation - spray
varnish, polyurethane, tung oil, etc. - without satisfying
results, and still using the wire brush method of cleaning,
I read about the method of electrolysis being used by
several of the artillery experts.
If you look up
the definition of electrolysis in the dictionary youíll find
that it is ďa chemical change produced by an electrolyte by
an electric current.Ē And thatís the entire operation in a
nutshell, but the procedure has several steps involved in
reaching the goal of a clean projectile. Your primary goal
in using electrolysis is to remove as much rust (and
decomposed metal) as possible.
The old method
of electrolysis used a metal container which held the water
and lye solution in which the projectile was placed. The
fact that a battery charger was hooked up to the container
caused it to be dangerous to anyone who touched the
container while it was in operation. Besides, the
combination of lye and electricity caused a hazardous gas to
develop. And, after a few operations, the container
developed holes and leaked, thereby making it necessary to
obtained another on frequent basis.
Jack Melton, who
is the author of several artillery projectile identification
books and an artillery expert, had been using the old method
for several years. After some serious discussion about the
advantages and disadvantages of electrolysis Jack and I
decided to make a few changes of our own in the basic
operation in order to make it as safe as possible. I think
this method is less harsh on the projectiles as well as
being safer than the old method, so Iíve been using it for
the last ten years or so.
1. For most
artillery projectiles a 3 Ĺ - gallon plastic bucket is
adequate. For larger projectiles a 5-gallon bucket might be
needed. These buckets can be cheaply purchased in home
2. In order to
supply the electricity needed I use a battery charger which
has two amp selections (2 and 6) and two voltage settings (6
and 12). Although I usually use 2 amps and 6 volts, I have
had a need for the higher settings on really encrusted
items. Do not use a trickle charger.
3. There must be
an electrolyte present in the water in order to allow the
electricity to pull the rust away from the projectile. While
many collectors use lye or salt, I found that common baking
soda does just as good a job of cleaning. It is less
dangerous in that the amount of fumes given off is very
minuscule (but donít lean over the tank for long periods of
time as it can cause your nose to burn) so the process can
be done inside the basement or garage. Baking soda also
allows you to handle the projectile immediately out of the
water (after the battery charger is unplugged!!!)
without protective gloves. It is also not as harsh on the
projectile and, as a result, you can leave a projectile in
the tank during the operation for an extended period of time
without ďburning.Ē And it doesnít bubble up as much as lye,
so you can clean closer to lead sabots without damage
(however, the first operation may cause some foaming).
4. In order to
conduct electricity into the tank, I use Ĺ -inch copper
refrigerator line found in home supply stores. Some people
use brass, but brass is hard (and expensive) to find in
large sheets. The only disadvantage I found with copper is
that brass sabots and fuses have a tendency to pick up a
reddish coloration which is noticeable if the brass is
shined up (which is not recommended anyway). But more about
5. I coil the
copper line inside the tank, getting the best coverage
possible but without allowing the copper to touch itself. I
flatten and bend enough of the top end of the copper so it
can be connected with the battery charger without being
under water. I also crimp the bottom end as the copper seems
to last a little longer by not having the water running
through it at the beginning of the process. Holes will
slowly appear in the copper but this technique gives the
copper a fighting chance.
6. I fill the
bucket with water to a level appropriate for the size
projectile Iím trying to clean. The objective is to
completely immerse the projectile (with exception of
Hotchkiss shells as I will explain later). I prepare the
baking soda by dissolving about half of a small box of soda
in two cups of hot water. Pour the solution into the tank
and stir until it is well mixed.
1. I wash as
much mud and loose dirt off the projectile as possible. I
find it advantageous to let the projectile soak for a couple
of days in plain water. This seems to loosen the mud and
dirt better and allows the electrolysis procedure to work
2. In order to
allow the electricity to clean the projectile there must be
a contact running to the projectile. This means the
projectile must have a good contact point. Once the loose
mud is removed, I try to find a small section of the shell
where bare metal is present or I scrape the mud off a
dime-sized section down to the metal. I try to locate an
easy drill area on the projectile where the metal may be at
its thinnest so a hole can be made easily and at the proper
depth. This is important as, once again, good contact must
3. I use a
small-gauge copper wire from scrap electrical wire
(construction type - not extension cords) as the contact
with the projectile. In order to do this a small hole, 4-40
is recommended, is drilled into the shell at the cleaned
area made previously. I highly recommend a drill press as a
hand drill is apt to wander and break the bit.
First, I secure
the projectile so it will not have a tendency to move during
the drilling, thereby causing the bit to snap off. I built a
cradle for use with elongated projectiles and I use the hole
in the table of the press to secure round projectiles. I
also make sure the bit will be going in straight rather than
ďridingĒ the shell and going in at an angle.
Second, I place
a small drop of clean motor oil on the area Iíve chosen as
my contact. I also use oil on the drill bit. Oil doesnít
transmit as much heat as water so it is better for the bit
as well as the process of drilling.
Third, I drill
the hole only deep enough to adequately secure a 4-40 brass
screw. Once the hole is bored I use a 4-40 metal tap to
thread the hole. Be sure to wipe the tap with a little oil
before using and donít force it, otherwise youíll plug the
hole with the broken tap. Wipe excess oil from the area.
the wire to the projectile by making a small loop at the end
of the wire and set with the brass screw. Apply only the
pressure needed to keep the wire from moving around -
otherwise the head of the screw will twist off. The wire and
screw can be used several times, but they must be cleaned
off with a wire brush before each use.
Fifth, make a
larger loop on the other end of the wire to help clamp the
wire to the battery charger.
1. Place the
projectile in the tank with the copper wire extending above
the surface of the water. Make sure the projectile is
sitting or lying as flat as possible without touching the
copper coils. I find it easier to use a construction brick
(type with holes in it) as a base for round projectiles and
projectiles which cannot stand alone. Elongated projectiles
clean better if they can be stood up.
Hotchkiss shells, as well as any other shell with a lead
sabot in the middle, have to be cleaned twice - once for the
nose and once for the base. These shells also require two
holes to be drilled. Make sure the water level does not
touch the lead sabot. The same holds true for pewter or lead
fuses - make sure they are not covered by the water as they
will turn gray during the process.
3. Clamp the
POSITIVE end of the battery charger cables to the end of the
copper coil and the NEGATIVE end to the copper wire from the
projectile. Plug the battery charger in and observe the
projectile. If tiny bubbles are rising from around the
projectile there is good conductivity. If not, UNPLUG
the charger and reset the clamps making sure there is a
tight fit. For projectiles without much rust there may not
be signs of bubbles, but if everything is tight the process
encrusted projectiles take 10 - 12 hours to loosen the rust,
while projectiles with little rust usually clean within 8
5. In order to
see if the projectile has received its maximum cleaning I
test the projectile. UNPLUG the charger, take
the clamp off the cooper wire and lift the projectile out.
If the projectile can be wiped off with a cloth or the rust
is ďeggshellĒ (meaning it can be easily cracked off) itís
ready to clean. If not, it goes back in for a few more
hours. Remember, baking soda does not seem to burn up the
projectile like lye does so it doesnít hurt to over-extend
Cleaning of the Projectile
1. After I
remove the wire and screw from the side of the projectile I
scrub the projectile in clean water with a brass brush. This
does not harm the projectile - it simply helps remove the
loose rust and the reddish deposit left by the electrolysis.
I lightly scrub any sabots or fuses to clean off any
deposit. As I stated earlier, brass will take on a reddish
hue which can only be seen if it is highly polished. A shiny
fuse or sabot gives the shell an artificial appearance so
itís best to do a quick brushing and then leave them alone.
usually does not clean out the deep grooves manufactured in
the projectile (usually found around the sabot area). For
this cleaning I use WOOD chisels. Lightly tapping the chisel
with a small hammer will help remove the rust and other
debris in this area. Just take time and use light taps,
otherwise there is a possibility of chipping good metal.
Donít use METAL chisels as these will definitely cause
damage. I also use soft wire brushes (aluminum or brass) to
further clean the grooves.
3. After I rinse
the projectile again in clean water, I inspect if for any
stubborn rust patches, removing what I can with chisels and
4. If everything
is satisfactory, I let the projectile air dry for several
days in a humidity controlled environment. This allows any
moisture which penetrated the projectile during the process
to dry out.
projectiles will have small divots remaining which are
caused by the action of the rust over the century. This is
normal and no attempt should be made to fill these holes or
to smooth them out. I have encountered projectiles that have
received a treatment of metal putty either in spots or, in
some instances, over the entire projectile. To most
collectors this is considered to be fraudulent and devalues
The method used
to preserve a projectile is up to the individual. Some
people say to leave a little patina to make it look old.
Thatís the golden rule for non-harmful patina such as found
on lead and brass. But patina on iron is also known as
ďrust.Ē This has to come off, otherwise the projectile will
continue to deteriorate. And that is exactly the goal of
electrolysis. Not coating the shell with a preservative will
defeat the goal.
I know some
people who use tung oil, and thatís fine if you want a shell
with an oily layer on it. However, oil doesnít plug up the
pores in the metal and also attracts dirt. Motor oil is
out for obvious reasons. I also donít use varnish or
polyurethane as they are less likely to preserve and protect
I prefer to hot
wax a projectile with a product known as Bri-wax. This wax
can usually be found in furniture or craft stores. I use a
dark color in order to cover the ďjust cleanedĒ look most
projectiles take on after electrolysis. Iíve used this for
over a decade and my customers have been most satisfied. In
fact, dealers find that a wax preservation adds to the value
of the projectile.
In order to
preserve the projectile I do the following:
1. Heat the
projectile to a point where itís hot, but can still be
handled with gloved hands. This allows the pores in the
metal to open and also forces any trapped water to the
surface. If the projectile is a solid shot or an unloaded
shell, donít worry if it gets overheated. Just let it cool
down and reheat. However, a loaded shell should be monitored
closely as they could explode
I have not heard of this happening there is no use in taking
place the projectile in the oven to heat it. I have heard of
one relic hunter heating an explosive shell in the oven to
the point where it starting sizzling. He got scared and
threw the shell out the door. It was probably water in the
shell heating up, but it sounds as if it was overdone. And
thatís the problem with using the oven - itís hard to
Iíve also heard
of people heating the wax instead of the shell. That is
extremely dangerous as most wax is highly inflammable. The
wax also has a tendency to evaporate when heated.
I use a heat
lamp secured just above the projectile. Using this method
allows me to periodically test the projectile to determine
the point at which itís ready to be waxed.
2. I place the
heated projectile on newspapers and start applying the wax
with a small brush as if I was painting it. It is important
not to let the wax run onto lead sabots or fuses as it will
stain them permanently. I apply the wax to any brass sabots
and fuses and continue to paint the shell until the wax
begins to solidify.
3. I also use a
dark furniture repair pencil to stop up the screw hole. I
simply twist the pencil into the hole until it is full, then
break it off. The wax will melt into the hole and, after the
final brushing, it can hardly be seen.
4. It is
important to begin brushing the wax out once it starts
setting up. Otherwise the final finish may show streaks
where the wax collected. For this process I use an old shoe
brush and have it marked for the initial brushing as opposed
to another I use for the final buffing. The brush will
gather wax so it needs to be brushed against newspaper
periodically to clean the bristles.
5. I then let
the projectile cool off for several hours. This allows the
wax to harden inside the metal pores which helps prevent
moisture from entering the shell from the outside.
6. After the
projectile has cooled off, I buff off any excess wax with
another shoe brush paying close attention to the brass sabot
and fuse. I also make a pass or two over any pewter or lead
fuses as this tends to highlight numbers of Bormann fuses
and very slightly darkens the stark white patina on other
fuses. Be careful not to overdo this.
7. For final
buffing I place the shoe brush in a white cotton sock and
buff the projectile with short hard strokes. This removes
the tacky film from the surface left over from the drying
process. The projectile should be buffed until it no longer
And thatís it!!
The projectile is now ready to display.
shell on the left is the new method of cleaning and waxing.
The Hotchkiss on the right is an example of the old method
used by many people. Note the shell on the right has been
coated with a clear substance which has continued to rust
A Word About
I have found
that projectiles with metal cancer do not electrolysize well
as too much metal is lost. As stated before, the cancer is
caused by the projectile being immersed in a wet or swampy
area or excavated deep within a hard packed clay area.
Moisture is a serious enemy of iron and many of the
projectiles I have seen lately have large patches of cancer
- large chunks of iron missing or cracks developing. It may
not be apparent when the projectile is first excavated, but
over a short period of time the cancer will present itself.
Because of the depth that most projectiles are being found
today, I have seen many more cancerous ones over the past
few years than ever before
Many times, a
projectile is not determined to be cancerous until it is
being prepared for electrolysis. If, in the process of
drilling the small hole, the drill bit goes in rapidly, or
the projectile skin ďcratersĒ around the hole, thereís a
good chance the projectile has cancer.
thing to do in case of a cancerous projectile is to hand
clean it with the chisels and wire brushes to remove as much
rust as possible. Then hot wax it and it will last a little
longer. I have a 30 lb Parrott shell that came from the
Savannah area and I tried to preserve it the old fashion way
(varnish) more than 30 years ago. It slowly lost the
exterior layer and developed a large crack in the side. I
removed the varnish and hot waxed it several years ago and
it seems to have stabilized somewhat (of course it looks
more like a 20 lb piece of iron than a shell).
Electrolysizing Small Relics
a very successful method of cleaning larger metal objects
such as projectiles, gun barrels, lock plates, and bayonets.
I would not recommend using it for any smaller pieces as
many times rust is the only thing holding the part together
(this is especially true for bullet worms and wipers). Tin
items should also not be cleaned by electrolysis due to the
the above mentioned items, an area must be cleaned off as
complete as possible in order to wrap the conduction wire
around the object - it is too difficult to try to drill a
hole in the steel bayonet, barrels, or lock plates. The wire
must be secured tightly, otherwise the process of cleaning
and preservation is the same.
Some Doís and
1. DONíT touch
the water, wire, or coils in the electrolysis tank while the
charger is plugged in. The result is a nasty experience and
could electrocute you. The outside of the plastic tank can
be handled if necessary. However, pay attention to the wire
handle - if it is encased in plastic above the level of
water it should be harmless, but I would not fool with it
while the process is underway.
2. DONíT breath
in the fumes from the tank over an extended period of time
as it can make you sick. However, it is safe to use the
baking soda procedure in a large enclosed area such as a
carport, garage, or basement as the fumes are rapidly
dissipated by the oxygen in the room. I would also recommend
that the tank NOT be located right next to an open flame
appliance, just in case. The fumes are not very flammable,
but no use taking chances.
3. DONíT drill
the purchase hole in an armed shell too deep or you could
enter the powder chamber and set the shell off. I havenít
heard of any shells exploding because of this but thereís no
use being the first victim.
4. DO try to
have the explosive shell unloaded BEFORE the electrolysis
process - not because the electrolysis procedure might
explode the shell, but because the process of unloading may
ruin the wax finish on the shell.
5. DONíT TRY TO
UNLOAD A SHELL YOURSELF!!! There are several experts around
who can do this for you. They have the proper equipment to
do it safely. Loaded shells have a tendency to deteriorate
from the inside because the powder causes a reaction with
the iron. Although this process takes many years to
accomplish, it is advisable to have the shell unloaded,
especially if it has an air-tight fuse.
6. DONíT worry
about the copper lines turning green. This happens quickly
and it is caused by the action of the electricity and baking
soda. I scrape the coil with a steel wire brush after every
third projectile cleaned just to remove some of the
7. DO change the
water/baking soda solution periodically depending on the
number of projectiles being cleaned. The water will become
ďheavyĒ from the debris removed from projectiles, corrosion
of the copper lines, and the action between the baking soda
and the electricity.
8. DO check the
copper lines periodically for signs of corrosion. Thatís the
beauty of using them instead of a metal tank - itís much
easier to replace the lines and you donít spring a leak.
When the lines have so many holes in them that they are in
danger of breaking apart, replace them with new lines.
9. DO clean the
copper wire and brass screw between each use. These items
will present a burned appearance and need to be wire brushed
in order to make good contact on the next projectile.
10. DONíT heat
the wax up - heat the projectile instead. Hot wax is
dangerous and highly flammable.
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