electrolytic derusting (EDR) question
 

I have this old set of casters I'm trying to save. Steel everything, quite
rusted. They still turn but sound like a sack of cats. These don't disassemble
and the replacement ones have plastic wheels. Yuck. So I'm trying to get the
rust off. These are stem casters, 7/16"x1-9/16" stem, 2" wheels. Yesterday I
suspended one by the stem into an electrolytic derusting solution and gave it
a whirl. The caster housing derusted beautifully but there is apparently too
little electrical contact with the wheel to have any effect.

How can I EDR the wheel? I thought of soft-soldering a wire to the rim of
the wheel and suspending it by the wire (with just the top of the wheel
out of the solution). Is there any better way?

GWE -- rookie EDR'er

In article , Grant Erwin says...

I have this old set of casters I'm trying to save. Steel everything, quite
rusted. They still turn but sound like a sack of cats. These don't disassemble
and the replacement ones have plastic wheels. Yuck. So I'm trying to get the
rust off. These are stem casters, 7/16"x1-9/16" stem, 2" wheels. Yesterday I
suspended one by the stem into an electrolytic derusting solution and gave it
a whirl. The caster housing derusted beautifully but there is apparently too
little electrical contact with the wheel to have any effect.

How can I EDR the wheel? I thought of soft-soldering a wire to the rim of
the wheel and suspending it by the wire (with just the top of the wheel
out of the solution). Is there any better way?

I'd go with a big alligator clip, like for jumper cables. How
wide are the wheels?

Jim


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please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
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"Grant Erwin" wrote in message
...
I have this old set of casters I'm trying to save. Steel everything, quite
rusted. They still turn but sound like a sack of cats. These don't
disassemble
and the replacement ones have plastic wheels. Yuck. So I'm trying to get
the
rust off. These are stem casters, 7/16"x1-9/16" stem, 2" wheels. Yesterday
I
suspended one by the stem into an electrolytic derusting solution and gave
it
a whirl. The caster housing derusted beautifully but there is apparently
too
little electrical contact with the wheel to have any effect.

How can I EDR the wheel? I thought of soft-soldering a wire to the rim of
the wheel and suspending it by the wire (with just the top of the wheel
out of the solution). Is there any better way?

GWE -- rookie EDR'er
Grant,
Use steel wire and get it on to the wheel mechanically, wrap and twist, dip
the whole assembly. If there is still an oxide film under the wire move it
and redip.

Ed Angell

jim rozen wrote:
In article , Grant Erwin says...

I have this old set of casters I'm trying to save. Steel everything, quite
rusted. They still turn but sound like a sack of cats. These don't disassemble
and the replacement ones have plastic wheels. Yuck. So I'm trying to get the
rust off. These are stem casters, 7/16"x1-9/16" stem, 2" wheels. Yesterday I
suspended one by the stem into an electrolytic derusting solution and gave it
a whirl. The caster housing derusted beautifully but there is apparently too
little electrical contact with the wheel to have any effect.

How can I EDR the wheel? I thought of soft-soldering a wire to the rim of
the wheel and suspending it by the wire (with just the top of the wheel
out of the solution). Is there any better way?


I'd go with a big alligator clip, like for jumper cables. How
wide are the wheels?

Don't have one, really good idea though.

===========

Use steel wire and get it on to the wheel mechanically, wrap and twist, dip
the whole assembly. If there is still an oxide film under the wire move it
and redip.

Ed Angell

This one I thought of. It's a great idea too. I don't have any wire that
isn't galvanized, though. I actually did solder on a stranded copper wire
and it's cooking right now. I'm normally lousy at soldering anything except
electronic components but I just kissed the face of the wheel on the disk
sander to get a clean spot and my ancient roll of rosin core solder stuck
to it fine.

The bubbling action I'm getting isn't very aggressive, although the test run
yesterday realized good results in about six hours. I don't have a DC ammeter.
I do have an AC ammeter. I'm planning to cobble up a setup using a variac and
a rectifier bridge and to put the AC ammeter in series between the variac and
the bridge. My brain is too far removed from electronics to be able to suss
out the relationship between AC current upstream of a rectifier, and DC
current downstream. Anyone know?

GWE

Ignoramus21451 wrote:

What kind of volts and amps should one use for EDR?

Can you describe the process a bit?


http://www.stovebolt.com/techtips/ru..._derusting.htm
http://antique-engines.com/electrol.asp
http://www-2.cs.cmu.edu/~alf/en/electrolysis.txt
http://www.woodmangler.com/Derusting...derusting.html
http://www.metalwebnews.com/howto/rust/rust.html

I used an old plastic bucket, Arm & Hammer washing soda from Safeway (about
1/4 cup in a gallon), and a piece of old square steel tubing for the anode. I
sanded a spot clean on the outside corner of the square tube and drilled a
hole near the end, and threaded some stranded copper wire (stripped, of course)
through and twisted it tightly. I set the tube on a piece of PVC so the top
of the steel was just above the surface of the liquid, with the copper wire
(insulated, of course) hanging up over the top of the bucket. I attached another
copper wire to the steel caster to be derusted. I drilled a small hole in a flat
stick and ran the wire from the caster through the small hole, and put a clamp
on the upper side, then layed the stick over the bucket and arranged it so the
caster hung inside the steel anode without touching it, connected a small
automotive battery charger (red to anode, black to part, connection is critical)
and plugged it in. Six hours later I unplugged the charger, removed the part
(wire still attached) and ran very hot water over it while hitting it lightly
with a maroon 3M pad. Lots of black came off, and underneath - voila - no rust.
Except on the caster as my previous post indicated. Now I'm repeating the
test this time with the wire attached to the wheel instead of the caster stem.

GWE

For a transformer with a winding ratio of N1 ( pri ) and N2 ( secondary
), Voltage on the secondary ( E2 )
Voltage on the Primary ( E 1 )
Current on secondary ( I 2 )
Current on Primary ( I 1 )

E1/E2 = N1/N2 = I2 / I1 , E1 * C1 = E2 * I2

The first equation is the volttage steps up in the same ratio as the
windings.\
The current steps up in the inverse ratio of the windings.

The second equation is just power in equal power out ( neglecting
slight losses )

Dan

I forgot to mention that there is a imaginary current on the primary
side which is the magnetizing current. You can measure it by
disconnecting the secondary from the load and measuring the primary
current.. So don't try to measure the primary current and calculate
the secondary current.


Dan

On 6 Apr 2005 17:33:27 GMT, Ignoramus21451
wrote:

What kind of volts and amps should one use for EDR?

Can you describe the process a bit?

i

Download this handout. Sorry, it doesn't have pictures.

http://users.moscow.com/oiseming/rustdemo/rustdemo.htm

I've elaborated on it a bit more in Grant's post about tin cans.

Orrin

On Wed, 06 Apr 2005 08:20:56 -0700, Grant Erwin
wrote:

I have this old set of casters I'm trying to save. Steel everything, quite
rusted. They still turn but sound like a sack of cats. These don't disassemble
and the replacement ones have plastic wheels. Yuck. So I'm trying to get the
rust off. These are stem casters, 7/16"x1-9/16" stem, 2" wheels. Yesterday I
suspended one by the stem into an electrolytic derusting solution and gave it
a whirl. The caster housing derusted beautifully but there is apparently too
little electrical contact with the wheel to have any effect.

How can I EDR the wheel? I thought of soft-soldering a wire to the rim of
the wheel and suspending it by the wire (with just the top of the wheel
out of the solution). Is there any better way?

GWE -- rookie EDR'er

Grant, I have a handful of el-cheapo alligator clips that came out of
a junk box. They work well. Because of the polarity, they will not
be damaged by submergence in the solution.

You may need to file away the rust in order to make good electrical
contact.

Electrolytic derusting works very well on cast iron, less well on
steel.

Regards,

Orrin

I don't think you will be able to get inside a hole (the wheel) with
this process. If both the wheel and the axle ARE connected to the same
side of the power source, then the charges will be the same and no
electrolytic action will occur.


Pete Stanaitis
--------------------------

Grant Erwin wrote:

I have this old set of casters I'm trying to save. Steel everything, quite
rusted. They still turn but sound like a sack of cats. These don't
disassemble
and the replacement ones have plastic wheels. Yuck. So I'm trying to get
the
rust off. These are stem casters, 7/16"x1-9/16" stem, 2" wheels.
Yesterday I
suspended one by the stem into an electrolytic derusting solution and
gave it
a whirl. The caster housing derusted beautifully but there is apparently
too
little electrical contact with the wheel to have any effect.

How can I EDR the wheel? I thought of soft-soldering a wire to the rim of
the wheel and suspending it by the wire (with just the top of the wheel
out of the solution). Is there any better way?

GWE -- rookie EDR'er

I'm done with the casters now. The last 3 I did all at the same time -- wired
a steel wire around the rim of the wheel, then up and around the stem, twisted
tightly so it made connection to both the wheel and the caster body. They
didn't turn out perfect, but 90% of the rust came off. I worked some grease
down onto the axle with a sailmaker's needle and now they turn smoothly so I
believe the rust down there was dealt with. YMMV. - GWE

Pete & sheri wrote:
I don't think you will be able to get inside a hole (the wheel) with
this process. If both the wheel and the axle ARE connected to the same
side of the power source, then the charges will be the same and no
electrolytic action will occur.


Pete Stanaitis
--------------------------

Grant Erwin wrote:

I have this old set of casters I'm trying to save. Steel everything,
quite
rusted. They still turn but sound like a sack of cats. These don't
disassemble
and the replacement ones have plastic wheels. Yuck. So I'm trying to
get the
rust off. These are stem casters, 7/16"x1-9/16" stem, 2" wheels.
Yesterday I
suspended one by the stem into an electrolytic derusting solution and
gave it
a whirl. The caster housing derusted beautifully but there is
apparently too
little electrical contact with the wheel to have any effect.

How can I EDR the wheel? I thought of soft-soldering a wire to the rim of
the wheel and suspending it by the wire (with just the top of the wheel
out of the solution). Is there any better way?

GWE -- rookie EDR'er

By the way, there is another EDR method rarely mentioned on this NG, not
mentioned in any of the normal derusting papers. Orrin, this one may
interest you. The method is passive rather than active -- in other words,
you don't have to add energy in the form of electricity. No more wires.
Simple. Make up some strong hot lye, dissolve in a chunk of zinc, and
drop in the rusty part. The zinc reduces the oxidized iron.

There are Web pages about this -- google on lye and zinc and you'll see 'em.

If you don't think you have any zinc, you're likely wrong. Many inexpensive
cast metal items are made mostly of zinc. Car door handles, mirror bases,
lamp bases, stuff like that. Try a coarse file on it, if it peels away like
butter that's the stuff. It's been posted on this NG that lye will bubble on
zinc (pot metal) but not on aluminum.

Grant

"Grant Erwin" wrote in message
...
By the way, there is another EDR method rarely mentioned on this NG, not
mentioned in any of the normal derusting papers. Orrin, this one may
interest you. The method is passive rather than active -- in other words,
you don't have to add energy in the form of electricity. No more wires.
Simple. Make up some strong hot lye, dissolve in a chunk of zinc, and
drop in the rusty part. The zinc reduces the oxidized iron.

There are Web pages about this -- google on lye and zinc and you'll see
'em.

If you don't think you have any zinc, you're likely wrong. Many
inexpensive
cast metal items are made mostly of zinc. Car door handles, mirror bases,
lamp bases, stuff like that. Try a coarse file on it, if it peels away
like
butter that's the stuff. It's been posted on this NG that lye will bubble
on
zinc (pot metal) but not on aluminum.

Grant

pennies are thinly copper plated zinc.

On Thu, 7 Apr 2005 08:33:21 -0700, Charles Spitzer wrote:

"Grant Erwin" wrote in message
...

If you don't think you have any zinc, you're likely wrong. Many
inexpensive
cast metal items are made mostly of zinc. Car door handles, mirror bases,
lamp bases, stuff like that. Try a coarse file on it, if it peels away
like
butter that's the stuff. It's been posted on this NG that lye will bubble
on
zinc (pot metal) but not on aluminum.

pennies are thinly copper plated zinc.

They switched to that in 1982. So, 1983 or newer, yes. 1981 or older,
no. 1982, maybe.

There is also molasses as a passive bath. You buy the molasses pellet
feed that is sold for horses, mix it into water to make a slurry and
toss the parts in. Let them sit 1- whatever (depends on how bad the rust
is) days and when you take them out wash them clean.

--
Steve Williams

"Grant Erwin" wrote in message
...
By the way, there is another EDR method rarely mentioned on this NG,
not
mentioned in any of the normal derusting papers. Orrin, this one may
interest you. The method is passive rather than active -- in other
words,
you don't have to add energy in the form of electricity. No more
wires.
Simple. Make up some strong hot lye, dissolve in a chunk of zinc, and
drop in the rusty part. The zinc reduces the oxidized iron.

There are Web pages about this -- google on lye and zinc and you'll
see 'em.

If you don't think you have any zinc, you're likely wrong. Many
inexpensive
cast metal items are made mostly of zinc. Car door handles, mirror
bases,
lamp bases, stuff like that. Try a coarse file on it, if it peels away
like
butter that's the stuff. It's been posted on this NG that lye will
bubble on
zinc (pot metal) but not on aluminum.

Grant




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On Thu, 07 Apr 2005 05:58:24 -0700, Grant Erwin
wrote:

By the way, there is another EDR method rarely mentioned on this NG, not
mentioned in any of the normal derusting papers. Orrin, this one may
interest you. The method is passive rather than active -- in other words,
you don't have to add energy in the form of electricity. No more wires.
Simple. Make up some strong hot lye, dissolve in a chunk of zinc, and
drop in the rusty part. The zinc reduces the oxidized iron.

There are Web pages about this -- google on lye and zinc and you'll see 'em.

If you don't think you have any zinc, you're likely wrong. Many inexpensive
cast metal items are made mostly of zinc. Car door handles, mirror bases,
lamp bases, stuff like that. Try a coarse file on it, if it peels away like
butter that's the stuff. It's been posted on this NG that lye will bubble on
zinc (pot metal) but not on aluminum.

Grant

Grant, thank you for reminding me of that method. I'd heard of it,
recently, but the recipe I read called for heating a solution of lye.
It sounds a bit hazardous to me.

Indeed, most of us probably have zinc all around us and we don't
realize it. Die-cast pot-metal items are almost everywhere we look,
especially in the kitchen and bathroom.

Regards,

Orrin

Grant Erwin wrote:

It's been posted on this NG that lye will bubble on
zinc (pot metal) but not on aluminum.

Lye reacts very vigorously with Al.