Cleaning Rust off of free Lyman T-Mag

[Mike P. Wagner]

Someone from work gave me an old Lyman turret press. I don't think it's a T-Mag II - there is no place to put a turret handle.

There is some superfical rust that I'd like to get off of the piston. I was going to steel wool it, and then put on a light coat of the oil, but the T Mga II manual says graphite, not oil. Any seggestions?

Looks like a solid press. Definitely a lot of cast iron.


Mike

[brickeyee]

Steel wool (and oil if needed) to remove the rust, then degrease (paint thinnner, carb or brake cleaner, etc).
Oil around loading is a generally bad idea, so graphite would be fine.
If it will be in a humid area, paste wax provides some protection.

[Unclenick]

I've started using chelating rust removers (bio-degradable, non-toxic) like Evapo-Rrust, and Rust Release where there is any trace of more than the lightest surface rust. I follow up with a thorough cold water rinse, then suspend the part in boiling distilled water. If you have only very light surface rust, then degrease the work with Simple Green or Formula 409 or Greased Lightning and thoroughly water rinse, then go straight to the boiling.

Boiling is the conversion step in the antique rust bluing process. It converts red rust (ferric oxide, or hematite) to black oxide (ferric ferrous oxide, or magnetite). For some reason minerals in water interfere with or even prevent the conversion, plus they form water marks on drying. So, distilled, de-ionized, or reverse-osmosis treated water is recommended. After boiling about 15 minutes, you pull the part out, grab it with a towel (it's hot) and shake any remaining water loose. The surface water will flash dry from the heat and any trace of new oxide formed by the moisture will be blue/black. The whole surface gets a micro-coating of blue oxide that tends to protect it. This is why Chicago Cutlery recommends a hot water final rinse after cleaning their carbon steel blades.

Next you take degreased steel wool (steel wool has oil on it to prevent rust; give it two successive soaks in virgin denatured alcohol to remove it) and card the steel (rub away the loose black oxide). Some black spots will remain. This is the same as gun bluing, so ignore it.

The reason grease isn't recommended for lubricating the press ram is that a lot of primer and powder residue falls from cases during reloading and will stick to the oil and form a sludge that interferes with smooth operation. I recommend that if you are going to warm the thing in boiling water anyway, you try Shooter's Solutions Moly-Fusion Oil. This oil is a carrier for a yellow chemical suspension. You shake it up to keep the yellow material mixed and suspended, then rub it onto the hot metal surface for about 20 minutes, adding fresh oil as the old stuff thickens. The surface takes on a light yellowish gray appearance, which is a coating of molydenum phosphate forming. This is a metal conversion process, akin to Parkerizing, except the base metal is molydenum which creates a non-porous and highly lubricative layer about a quarter of a ten-thousandth thick (too thin to affect sliding fit). Think of it like puting a Teflon coating on the metal, but much thinner.

After the coating is formed, you clean all the oil carrier away with denatured alcohol. You are left with a permanently dry lubricated surface that is corrosion resistant as long as it remains intact. Unlike Parkerizing, this stuff also forms the coating on stainless or aluminum parts.

That reminds me: if you have rust on the ram, you also have it in the mating hole in the press frame. Get rid of it by the same methods or the rusting process will be seeded by the rust particles left there and will come back.

Nick

[RoscoeC]

This is a link to electrolytic rust removal from the British Horological Institute. I have used this, and it is effective, non toxic and fairly easy.


Electrolytic Rust Removal

Rust removal in the restoration of antique timepieces is a pretty common activity.

[Unclenick]

RoscoeC,

Electrolytic rust removal has been written up in shooting literature as well. I haven't tried it, but I read the description of it in the link you posted and a caution comes immediately to mind:

The post states that because voltages are low, no electrical hazard is present. But then it also recommends a battery charger for the power source. As an electrical engineer I assure you this advice can kill you! Most battery chargers are not medical grade devices and will not meet medical leakage current limits. This means leakage current from the A.C. line through the device and then through you on its way to ground can stop your heart.

The precautions to take are: Use only an outlet equipped with ground fault interruption (GFI) for the charger or any other AC source of power you employ, or else limit yourself to medical grade power supplies, or else acquire a medical grade isolation transformer large enough to run your charger. Do not touch parts in the live circuit; always unplug the power first. Wear dry rubber-soled shoes and don't stand in water or on damp concrete when touching any part of the circuit, including the power cord when plugging it in and out.

The statement that parts rust quickly after this process is completed suggests it leaves the surface activated, probably where the oxygen was removed from the iron. Rinsing and boiling as I described should take care of that.

The cathode bubble formation given as a sign the solution is working will be hydrogen bubbles (oxygen will be on the iron anode). This means the process will cause hydrogen embrittlement, so any heat treated part subjected to the process should be allowed to age a week afterward to let the hydrogen de-bond and egress before the part is subjected to stress. The military DOD-P-16232F specification states this is necessary for all steel parts hardened to Rockwell C scale 39 and higher. It is the only reference I have on the subject.

All that said, it is certainly something I want to try and, like the chelating solutions, should be very safe from the standpoint of toxicity and disposal. As the article states, the process is somewhat “line of site”, meaning the throwing power of the electrolyte solution to get current into holes, cracks and crevasses is not great. If you want holes and recesses de-rusted, it sounds like some iron anode wires need to be inserted in them. That’s one advantage the chemical de-rusters have, getting into tight spots.

Nick

[brickeyee]

"Do not touch parts in the live circuit" is the only advice you really need.
Most battery chargers already leak so badly they will trip a GFCI.
Meeting medical grade leakage is not a requirement for electrical safety.
The medical folks are concerned about stray curent to indwelling catheters and cardiac pacing leads and such. Once you are past the skin bodies are pretty good conductors, and when you are in a hospital you often have paths that go directly though the skin.
Current density as low as 10 mA/cm^2 in cardiac tissue are deadly. Getting that density to the heart is normally pretty hard at 120 V (and even 240 V).

[Unclenick]

Brickyee,

I phrased my reference to medical grade equipment poorly. I did not mean something has to be medical grade to be generally safe (most appliances are not) but rather that you couldn’t be certain of the leakage levels otherwise. That fact, in turn, could kill you in this particular situation because of the electrolyte present. The father of a friend of my college roommate killed himself “proving” that 12 VDC couldn’t kill you. He did this by putting a saline solution into two beakers, running a connection from each terminal of a car battery into each beaker, then shoving his hands into the beakers. Mind you, this was in Princeton, NJ in the sixties. The guy was probably a college professor or a defense department employee with some sort of technical background (hence, the beakers). The thing I don’t know is what kind of shape his heart was in to begin with? If you are prone to episodes of tachycardia or atrial fibrillation, it doesn’t take anything like enough current to do direct heart damage to nonetheless trip a potentially fatal episode of these problems; just enough to cause nerve twitching.

The idea that battery chargers are inherently too leaky to run from a GFI circuit, on the other hand, is enough to cost them UL approval for basic appliance safety. None of the three chargers I own has any difficulty running from the 120 VAC outlets in my garage, all of which are daisy-chained to a GFI. One of these chargers is an old metal box from the 70’s. Its construction precedes the double-insulated construction common today. If you have a unit that trips GFI circuits, you want not only to keep your hands out of the live circuit but off metal parts of the charger as well when it is plugged in.

An acquaintance of mine tells how a ship’s electrician he sailed with in the Navy would get drunk in port, come back aboard, unscrew a light bulb (240V on ship) in a corridor near the gangway, stick one index finger in the socket, then reach out with his other hand and touch people on the earlobe as they tried to walk past. Thought it was funny as all get out, and didn't seem to bother him. I’ve personally been knocked off a wood stool (completely insulated) by a spark that drilled a hole in the tip of my thumb and left my right ear ringing for three days. The blow from the fall caused a mild concussion, so I try keep in mind that a shock itself need not be the ultimate source of damage. The roommate whose friend’s father was killed once got a shock that caused him to see The Great White Light. His nose touched the “suicide” chassis of a 60’s era intercom while he was inspecting it, kneeling on a damp concrete floor wearing short pants. He woke up an hour later flat on his back. Brain did not like that.

Everyone’s shock tolerance is different and depends on the path through the body. My concern is that a number of us on the forum are getting to be of an age which no longer allows us to be as cavalier about what physical adversity we expose ourselves to. I think it is a case of better safe than sorry.

I stand by my assertion that the web article’s statement is incorrect that no electrical hazard existed in the described arrangement. I don’t want anyone here to become the one guinea pig in a hundred that proves it.

Nick

[Edward429451]

Dang Nick, is there anything you don't know?

[brickeyee]

Can low voltage kill? Damn straight.
Is it a hazard under normal circumstances? No.
Dry skin provides at least 10 kohms of resistance.
To drive a current that can even be detected by most people requires around 10 milliamps, and with a 10k resistance that works out to ~100 volts.
If your hands are wet the resistacne can fall to only a few hundred ohms, and the danger voltage declines significantly.
While the voltages used in an defibrillator for use through skin, even with conductive gell are very high (and often leave burns) in the surgical suite the open paddles that are used directly on the heart can operate at only a few volts.
There are many battery chargeres that will trip a GFCI if they arte actually charging a battery. Most are fine with no load.
It is the leakage currents around the battery that chiefly cause the nuisance trips. It only takes 5 milliamps to trip a GFCI.
The same problem occurs with the use of UPS supplies from a GFCI protected outlet.
I deal with voltages from logic supplies (down to 1.8 V now, but 5 V was used for many years), up to 120/240 V, 3 phase 440 V, 7.2 kV distribution wiring, and 20+ kV supplies for TWT amplifiers (let alone the 100 of kV supplies used to create ions at cyclotrons).
Unless you do something really dumb, 12 V is very unlikely to cause a problem. Shorting the things with a tool or jewelry is a bigger hazard from burns from vaporized metal then the chosk potential (I had an engineer loose a finger when a wedding band shorted a 5 V, 50 amp supply).
Keep your hands away from the stuff when running, and keep one hand in your pocket.

[RoscoeC]

Excellent safety information, Nick, et al. I have spent a good portion of my life in the jewlery industry, and have done this with a 25 amp variable plating power supply that I built many years ago. It was used day to day for plating and electro stripping duties, but I have used it for rust removal as well. The reason that I mentioned it is that it has been reported in a number of horological groups that I belong to, to be particularly effective on cast iron. There are all kinds of ways to skin a cat, this is just one.