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Preserving steel shot


#1

Hello everyone, Could you please share with me your tips on
preserving the steel shot when the tumbler is not in use? When I
(recently) bought my tumbler I was told that the steel shot has to
be kept in alcohol after each use. So after I first used the
tumbler i put the steel shot in rubbing alch.(70%) only to to find
that the NEXT DAY it rusted (slightly at the bottom of the
container)…Since then I kept tumbling it on it’s own day and
err…night in a mixture of water and that special soap that is used
for polishing metals.

Questions:

  1. Can I re-use the slightly rusted steel shot if I tumble it for a
    long time (until the rust is no longer visible)?

  2. How on earth do you keep the shot unrusted? Are there any (home
    use) inhibitors that I can use?

Thank you for your patience,
Irina


#2

Irina, The answer depends on the type of steel shot you purchased.
If you got carbon steel, then you may be out of luck. Stainless
steel shot is more expensive but will last a MUCH longer time and
will not require special handling to prevent rusting.

For carbon steel that’s showing signs of rusting, you might try
soaking it in Naval Jelly (available at home improvement/hardware
stores) until the rust is completely gone. Then dry thoroughly in
clean sawdust – you can use a magnet to remove the shot from the
sawdust once it’s dry. Store in an airtight container with a couple
of those “silica gel” packets like you get in new pairs of shoes –
they are designed to absorb any moisture and should help retard the
process of oxidation. The other thing you can do is store the shot
completely submerged in clean water. If the shot doesn’t touch the
air, it shouldn’t rust. Distilled water would be the best choice
for this to avoid any other type of mineral compounds that might be
lurking about.

But get the stainless steel at the first opportunity – you will
never go back!

Karen Goeller
@Karen_Goeller


Handcrafted and Unique Artisan Jewelry


#3
 So after I first used the tumbler i put the steel shot in rubbing
alch.(70%) only to to find that the  NEXT DAY it rusted (slightly
at the bottom of the container) 

70% alcohol is 30% water, and that’s enough to cause rusting. In the
lab I use a 96% alcohol for washing and temporarily protecting
polished steel specimens (ready for microscope examination). But for
long term storage I use a dessicator.

    2. How on earth do you keep the shot unrusted?  Are there any
(home use) inhibitors that I can use? 

There are a number of low-hazard inhibiting papers available,
similar to the anti-tarnish papers for silver. An industrial supply
or packaging supply company should have them. They work, but I have
no experience of how well.

Your main enemy is water, in both liquid and vapour form
(significant rust is inevitable on any unprotected steel if the
humidity is much above 60%). The dessicator I mentioned above is an
airtight box or glass jar containing a dish of sillica gel crystals
to absorb water. Get the type that has an indicator (goes pink when
it has absorbed water and needs regenerating) and regenerate as
needed by baking in an oven at about 80C (180F?) untill its all
turned blue again (about 30 mins).

After water, your next problem is that any contamination will make
rusting more rapid. Salt (even from the sweat of a finger) will set
off rust on an active steel surface. All of the jewellry metals will
form an electrolytic cell with any steel they are in contact with
(even a gold or silver dust particle), in which steel will
preferentially and rapidly corrode (this is often called dissimilar
metal corrosion). You can only prevent this by either removing all
trace of non-ferrous metal from the shot after use or excluding
water vapour. Copper is a particular problem as it accelerates the
chemical reactons of rusting.

This is all generic advice based on my knowledge of steel, hopefully
someone might have specific advice for your situation.

Iain Fielden Sheffield UK

PS. The only disadvantages I can see to keeping the tumbler running
are the waste of electric power and the wear on the equipment. If
these truly are the only disadvantages, you might consider running
your tumbler slow and/or using a time switch to run it for (say) a
few minutes in every few hours.


#4
   1. Can I re-use the slightly rusted steel shot if I tumble it
for a long time (until the rust is no longer visible)? 

]

   2. How on earth do you keep the shot unrusted?  Are there any
(home use) inhibitors that I can use? 

I deal with this issue as I wasn’t paying enough attention to what
kind of shot I was getting when I bought my tumbler. The first time
I used it I got a little rust but was able to tumble it away. Now
every time I use the shot I rinse it throroughly with hot water
and shake out the excess, then I lay it out on a towel to dry. After
it is completely dry I can then store it in a plastic container or
in the tumbler barrel as long as I am sure that both the storage
container and the shot are bone dry.

hth,
brigid


#5

Irina, it really is pretty simple. After tumbling, rinse the shot
completely. Spread out on a terry cloth towel one layer deep. Dry
with a hair dryer. Once you’re sure no moisture remains, pour into a
sealable container until your next use. A friend of ours has done
this and she’s still using a batch of shot purchased 7 years ago, and
it looks the same as the day she brought it home. Dry, Dry, Dry is
the key.

Betty


#6

After tumbling, I rinse my shot and pour it on a stack of paper
towels to completely dry out. I then put it in an airtight plastic
container with a couple of those silica gel (?) packs–you know, the
little packs that are often found in new shoes or other items to
absorb moisture. These seem to help keep the shot dry. If I do
discover some rust when I go to use the shot, I tumble it awhile in
the burnishing soap (I forget what brand it is), rinse (as the rust
is usually gone, then move on to my project. --Vicki Embrey


#7

Also keep in mind that coca-cola works miracles for cleaning "dull"
steel shot and making it shiny. This tip was taken here BTW, and has
served me well. My father once told me they used to shine brass
doornobs with coca-cola.

Jon, Montreal


#8

Irina,

I’ve been using the same carbon steel shot purchased (used) over 7
years ago it’s condition when received was pitted, coated with red
rouge and rusty. I used the coke method and followed the storage tips
very much like the ones below. They can be found in the Orchid
archives. I’ve saved them for times just like this.

Don’t throw away your shot until you give them a try.

From Deewo…
Sunday, May 30, 1999 9:17 PM

" Well, after telling all you Orchidites how my shot stayed
shiny bright all these years, the impossible happened: It turned dull
grey, would not respond to cleaning, and developed a spreading patina
of rust. Before dumping the whole lot out and investing in stainless
shot, I tried cleaning it with burnishing compound, which washed
off some of the rust; with ammonia and detergent, which washed off
more; but nothing would get rid of the dirty-looking opaque grey
finish on the shot. In desperation I turned to my personal file of
useful gleaned from Orchid e-mail, and guess what?
Coca Cola turned up as a great shot cleaner. (Not Diet Coke, not
Pepsi nor RC …just good ole Coca Cola) . So I cleaned the barrel
of my rotary tumbler, rinsed out the shot (still dirty grey
looking), added the fizzless Coke,turned the thing on and let 'er
roll. …all the while being very skeptical about this folk remedy.

After two hours, I took a peek. Marked improvement. So I
emptied the barrel, rinsed it, rinsed the shot, added more Coke
and repeated the process…"

From Peter Rowe
Saturday, May 29, 1999 9:58 PM

"you can get steel shot storage solution. You remove the shot
from the tumbling solution, wash it, and store it in this other,
rust inhibiting solution. that’s good for several days to a week
or so.

or long term storage, remove from the storage solution
again, don’t wash it, so it keeps a film of the rust inhibitors,
spread it on a towel under some lamps so it warms up and dries
quickly. Your then storing dried shot with a rust inhibitor on
it.

or shot that’s gotton rusty, if it’s not all pitted, you can
run it in a mildly acidic steel shot “conditioner” solution, that
will clean it right up. For really badly rusted shot, you can
add some actual polishing compound, like cerium oxide, linde a,
or other such lapidary type polish, to the conditioner. Then run
it a long time (couple days.). That will nicely restore the
shot. If it’s so rusted as to be all pitted, you may have to
throw it out, though I know one guy who treated it just like
tumbling rocks, starting with a handful of 600 grit, tumbled it a
week, went to the polish step for another week, and lo and
behold, he had newly reground and finished steel shot.

Easier, though, is to start with stainless steel shot in the
first place. About twice the cost, but well worth it in the
greater ease of care… "

Good luck!

Terri Collier
Dallas, TX

Please use this link to reply, thank you.
@Terri_Collier


#9

I still like the effective, oft-repeated home remedy for rusting
steel shot. Take a can of Coca-Cola, let it stand till the fizz
goes out of it, then pour enough of it into your tumbler to cover
the shot. Let it run for a couple of hours and your shot should
come out free of rust. If it’s still a bit rusty, empty the
tumbler, wash the barrel, pour the shot back in and repeat the
process. I gave up trying to dry steel shot, I just leave it in
its soap solution in the tumbler and it does just fine. No more
rust. Incidentally, the above-mentioned brand of Cola is most
effective. I don’t know how other brands or diet versions would
work. Dee


#10

Thank you all for the great response. I will follow your
instructions…Dry, dry, dry. This seems easy enough.

Iain and Karen, I have a question for you…Would it be possible to
create some sort of a cathodic protection for the shot when stored
in water? Something like using an aluminum alloy or magnesium strip
as sacrificial anode? Did anyone try this?

Thank you all again.
Irina


#11

I just leave the shot, water and soap in the tumbler and make sure
that the shot is completely submerged in water. I have not had a
problem with rusting. I left town for two months and didn’t use the
tumbler for another month but my shot has been fine.


#12

Irina

2. How on earth do you keep the shot unrusted?  Are there any
(home use) inhibitors that I can use? 

I use carbon steel shot in a tumbler. When I am done, I pour the shot
into a plastic strainer (like the ones you use for pasta) and rinse
with hot water. I let all of the excess hot water drain for a few
minutes I then pour the shot into a glass jar. I then cover the shot
in the jar with methanol (methyl alcohol). I fill the jar to about
1/2" over the top of the shot. Finally I place a lid on the glass jar

Methanol is very flammable, so you have to be really careful where
you store it. I keep it far from any ignition source.

When I want to use the steel shot again, I drain the methanol into a
second empty glass jar, and keep it for reuse.

I regularly add a bit of fresh methanol to the used methanol. About
every fourth use, I dispose of the methanol and start again with
fresh methanol.

I have been using this method for several years and generally do not
have any rusting problems

Hope this Helps
Milt Fischbein
Calgary Alberta


#13

Hi Gang,

Another thing that works great for cleaning rusted or grungy carbon
steel shot is Draino or lye (caustic soda, sodium hydroxide). Cover
the shot with water & pour in the Draino or lye. The amount needed
depends on the amount of shot. It’s better to go heavier on the
Draino/lye, it’s relativey inexpensive. When you rinse it off with
clear water, just dump it down the drain. An residual strength it has
will help keep your drain clean.

The best solution is to convert to stainless steel shot. It’s only a
1 time expenditure (about $15/lb) & it makes tumbler/shot maintenance
sooo much simpler.

Dave


#14

H Gang,

Also keep in mind that coca-cola works miracles for cleaning
"dull" steel shot and making it shiny. 

If you check the ingredients in Coca Cola, I think you’ll see
phosphoric acid as one of the ingredients. This is probably what
makes Coke so good at cleaning shot. Phosphoric acid is the main
active ingredient in Naval Jelly that’s sold for the same purpose.
I’d hazard a guess that if you got some phosphoric acid from a
chemical supplier & used it, it’d do a super job also.

Dave


#15
 I just leave the shot, water and soap in the tumbler and make
sure that the shot is completely submerged in water.  I have not
had a problem with rusting.  I left town for two months and didn't
use the tumbler for another month but my shot has been fine. 

Are you sure you’re using Carbon Steel shot, or did you pay extra
for Stainless Steel shot?


#16
    Iain and Karen, I have a question for you..Would it be
possible to create some sort of a cathodic protection for the shot
when stored in water?  Something like using an aluminum alloy or
magnesium strip as sacrificial anode?  Did anyone try this?  

I’ve not tried it with storing steel in water (my gut feeling would
be to store steel as far from water as possible), but the principle
is used to keep off-shore oil drilling rigs and ships in one piece
(where they have no choice about them being in water, and salt water
at that).

The sacrificial anode must be a metal less noble (i.e. more readily
oxidised) than the steel. Aluminium will have the opposite effect
from what you wish to achieve, the steel will preferentially corrode
and protect the aluminium from tarnishing. Magnesium would do well,
though in the corrosion protection industry zinc is the usual metal
of choice (cadmium is the best, but is so horribly toxic that its
not used for anything except safety critical aircraft parts).
Magnesium is more expensive than zinc and is so reacctive that it
might need replacing more often than you would like - hence it not
being the industrial choice.

There must be a metal-to-metal electrical connection between the
sacrificial anode and the metal you want to protect. So you need to
do something like storing your steel shot in a zinc lined flask, or
steel shot in a steel flask with an anode attached (adding some
third kind of metal to the equation makes things complex, though not
neccessarily non-functional). What you need to do is construct a
battery, so that oxidation occurs at the anode, the current flows
from there to the cathode (your steel) where the reduction occurs,
and then returns to the anode via the water.

One simple possiblilty would be to get a sheet of heavily zinc
coated (galvanised) steel, place it in the bottom of a non
conductive container (like a plastic food storage tub) and pour the
shot on top of it. Replace whenever the zinc is wearing thin.

The other possibility is impressed current cathodic protection. In
this the protective electric current comes not from the chemical
reaction of the zinc, but from an external battery or power supply.
Connect it up so that the steel is connected to the cathode (-) and
another piece of metal (scrap steel, stainless, zinc… its fairly
unimportant) is the anode (which will be corroded). the current path
in this case is steel-battery-anode-water- and back to the steel.
Voltage is single figures (3 to 5 at a guess) and for a few handfuls
of shot, current should be a few milliamps (at a guess) - so a
battery would be quite practical. If bubbles of gas are visibly
rising from the steel shot then you are driving too much current
through and you need to reduce the voltage by using a smaller
battery or putting some resistance in the circuit. If the steel
rusts then you need more current and/or shorter distance from steel
to anode. The disadvantages of using too much current are 1) your
battery runs down quickly - and the cost of batteries adds up (plus
used batteries are environmentally nasty - though you could use
rechargeables) 2) you may cause hydrogen embrittlement of your steel

  • probably unimportant for tumbling shot, but disastrous for a
    cross-country gas pipeline (which is what this technique is often
    used for).

If you are going to do either of these, use the purest water you can
affordably get, and drive off as much oxygen as possible by boiling
the water then stroring it in an airtight container with as little
air space as possible.

Iain Fielden
Sheffield UK


#17
    If you check the ingredients in Coca Cola, I think you'll see
phosphoric acid as one of the ingredients. This is probably what
makes Coke so good at cleaning shot. 

Dead right.

    I'd hazard a guess that if you got some phosphoric acid from a
chemical supplier & used it, it'd do a super job also. 

Also right, but full-strength (or even quite well diluted)
phosphoric acid is rather dangerous stuff. Its one of the more
aggressive acids on skin (though by no means the worst). If I recall
rightly, rather than causing the more usual “burn” (as if that
wasn’t nasty enough) a small amount will raise a large and
exceptionally painful blister.

Generic cola is a strong enough phosphoric acid solution to achieve
metal cleaning, and weak enough to be skin safe (though not tooth-
safe) its also cheap. Lab strength acid is dangerous, relatively
expensive, and after diluting it to a useful strength you will
probably find that the minimum possible purchase amounts to several
lifetimes supply - giving an ongoing problem/risk of storing a
dangerous substance.

Iain Fielden
Sheffield UK


#18

"Simple Green "works very well as a liquid to polish and to clean
the shot. It’s not harmful to the enviroment !!! Kills three birds
with one stone . Helen


#19

Am truly amazed at all the time and effort put in to keeping steel
shot rust-free and dry. Not necessary at all. Rio Grande has an
excellent Steel Shot Storage Solution. You finish your run, clean
the shot and drain, then put it back in your storage container in the
solution. Same solution. Only thing you need to have is a really
good and sturdy fine mesh strainer for A. draining the shot out of
the storage solution, rinse and put into the tumbler, and B.
draining it out of the tumbler, rinse and back into the storage
solution container. No time, no mess, no hair dryer or towels. Try
it, you’ll like it. I’ve never had rust over many, many years and
when this shot wears down to nothing, I will probably switch to
stainless - just to save the bother of buying the storage solution,
not the cost.

Pat


#20

Iron and steel are ok from corrosion in a generally oxygen free
alkaline environment. Proper wet storage is OK. “Real” soap will be
alkaline as will any of the burnishing solutions sold for the
purpose. You can always make sure the storage solution is alkaline
with a little washing soda ( sodium carbonate ) or baking soda
(sodium bicarbonate) . A filming amine will also help and car
antifreeze will contain these and probably some other corrosion
inhibitors which won’t hurt anything. Just don’t drink it. Distilled
or deionized water by itself is NOT good . Pure water is very
corrosive as it “wants” to pick up any available ions. Tap water
in most places will be alkaline particularly west of the Mississippi
river in the US . You can check with your water company for
guidance. A Ph more than 7 is alkaline.

Jesse