Tag "lead-rot"

Lead Rot Cleaning Pt.2 – episode 8

Seventh Episode Here.

Lead rot damaged the base and a few details.

Before treatment the miniature seems badly damaged, but after removal of the oxidation layer the condition isn’t so bad.

There are very thin crackles on some details, mostly on the fur and chainmal, so  these will be disappear easily  after priming.

The face and the helmet horns will require a small intervention: the face a bit of smoothing near the nose and the horns loose a bit of shape and pointy ends – some green stuff will repair them.

The biggest damage is on the base, I will first straighten it, eventually with some small pliers and rubber/plastic covers (to not damage the metal), then I will level the bottom or make it thicker with epoxy, eventually mounting the mini to a large base (plastic, resin or high density plaster).

Here’s the technical article on lead rot removal.

I’m offering a miniatures cleaning and restoration service, in case you’re interested.

Lead Rot Cleaning Pt.2 – episode 7

Sixth Episode here.

This time the lead rot couldn’t damage the miniature alloy:

The metal isn’t really damaged, on the whole mini’s surface there’s this thin matte patina, with slight variations in strength.

However I don’t like the idea to just spray the primer over the oxidation layer -it could detach, chipping away the paint, or worse… maybe attacking the area nearby.

So I just put the miniature in the electrolytic bath and after undergoing the process it comes back shiny!

I’m offering a miniatures cleaning and restoration service, in case you’re interested.

Eigth Episode Here.

Lead Rot Cleaning Pt.2 – episode 6

Fifth Episode Here

This time a multi-part miniature, lead rot or some other trauma detached the small creature from the carpet:

Before treatment the figures were really ugly and looked damaged.

After it, the carpet can be used with minimum further intervention, just a bit of cyanoacrilate or liquid putty in a pair of small details, to better define the damaged pattern. The hole will be hidden by the wizard figure placed on top of it. Of course it’s also possible to seal it and recreate the small part of pattern there, in case it will be used “standalone” (not a lot of sense in it, though).

The wizard can be painted right away (well, after cleaning the mold lines that are still there 😉 ), the small fissures in the mustache will be used as further details.

The small familiar/homunculus has to be of course reattached to the carpet, where I think it originally was waving. The damage on him is also minor, cyanoacrilate or liquid putty will seal the small fissures.

I’m offering a miniatures cleaning and restoration service, in case you’re interested.

 

Next Episode here.

Lead Rot Cleaning Pt.2 – episode 5

Fourth Episode Here

Another very bad case of lead rot:

Even before the treatment the legs are missing, probably completely destroyed by lead rot.

After the treatment is possible to see that damage is extensive, some details are gone, even from the face.

The legs must be fully resculpted or taken from another miniature or spares.

Also the sword has some damage in a place were the lead rot managed to chew through, but this can be easily fixed with epoxy.

The shield has some minor fissures that can be filled or kept as signs of wear.

The armor is fine, being chainmail has a pattern that is difficult to break with random detail changes.

Maybe some more small features are gone from the arm or fur, but it’s possible to put more elements there just by painting.

I’m offering a miniatures cleaning and restoration service, in case you’re interested.

Sixth Episode Here

Lead Rot Cleaning Pt.2 – episode 4

Third Episode Here

This is one of the “bad cases” of lead rot:


The legs and part of the weapon are gone, nothing to save… However cleaning up the remains will permit to restore or use the body for a conversion.

After cleaning up one of the horns needs to be strengthened and restored with some epoxy putty because the rot chewed through it, near its base.

The weapon can be restored by adding a blade or the head of an hammer, while the legs need some sculpting or getting a part from some other miniature.

I’m offering a miniatures cleaning and restoration service, in case you’re interested.

Fifth Episode here

 

Lead Rot Cleaning Pt.2 – episode 3

Second Episode Here

Here’s another miniature cleaned from lead rot:

Here also the damage was superficial. After the cleaning few areas still showed a bit of damage:

-Some superficial crackles on the sword’s blade. This can be left here, for a “old and rusty” look, or filled with a thin layer of liquid putty.

-Other light crackles on the robe, figure’s left side. After painting they will give the robe a tattered look, or they can also be filled with liquid putty.

-The base frontal section, the pointed part, has a deeper crackle that weakens it, I poured an half drop of cyanoacrylate and that strengthened it back.

I’m offering a miniatures cleaning and restoration service, in case you’re interested.

Fourth Episode Here

 

Lead Rot Cleaning Pt.2 – episode 2

First Episode Here

Here’s another mini that underwent the process of lead rot removal:


The results are good, there were only minor areas covered by rot, so no loss of details, those were the parts affected and the outcome:

-The back of the greaves shows some jagged edges, it will give them a more “used” look.

-There’s damage on the left leg that can be easily fixed with some epoxy putty where the lead rot chewed in.

-Unfortunately the sword was kept together by the oxide and the blade detached, you can see it on the ground, below the figure. It will be reattached or a substitute will be used.

-The left foot shows a deep crackle after the process, it was previously hidden by the oxidation layer. The more effective way to deal with this is probably to just pour some fluid cyanoacrylate  in it and let consolidate.

-The sheath on the right hip will require another small bit of epoxy to fill another fissure and make it smoother.

I’m offering a miniatures cleaning and restoration service, in case you’re interested.

Third Episode Here

Lead Rot Cleaning Pt.2 – episode 1

Finally I’ve cleaned some other figures of lead rot…

the results of course depend a lot on the oxidation depth. (If you missed the first article, explaining the process, it’s here)

However in most cases the affected miniature can easily restored after the electrolytic reduction process.

I will show the result in a series of videos that I’ll publish in a few episodes, let’s get to the first:

A nice figure, characterized face… I would say a early gnoll or a goblin, with hide armor and a club, later I’ll do some research to identify it (him)

The damage done by the oxidation to the overall miniature surfaces is minimal, after treatment the metal is compact and without fissures or crackles.

Only one part will need further intervention: the right leg. It appears the oxidation attacked the base of the legs, specifically the right one, practically chewing through. Luckily the figure’s club sustains it, so the excessive stress put on the left leg (also slightly damaged) didn’t break it.

A small amount of green stuff will complete the restoration, the figure will then be ready for priming (and painting!).

I’m offering a miniatures cleaning and restoration service, in case you’re interested.

Second Episode

 

Lead Rot Cleaning Pt.1

Recently I acquired some old miniatures and I faced the dreadful curse of all metal minis collectors: oxidation, commonly known as “lead rot”. I’ve done some research and I’m trying different methods for cleaning the minis and restoring them.

 

LEAD ROT – HOW AND WHY

This plague affects, in its worse form, old miniatures made with an high lead concentration alloy (or pure lead). Different alloys and newer miniatures, made of “white metal” and the like, are less affected or totally unaffected.

The metal will be covered by a white or grey substance, that will range in its form form a powder to a crust, depending on the gravity of the oxidation process. Under this layer the metal will be damaged -it transformed into that superficial layer-, in some cases the damage could be so severe it looses its structural integrity and the poor miniature could literally fall into pieces or disgregate.

A bad lead rot case

A bad case of lead rot

Primed or painted minis are less affected or immune, but some factors can cause the lead rot and/or accelerate it anyway: from research and experience wood and moisture are a deadly combination. Specifically it seems that woods (especially hard woods) release the tannins attacking the metals and bad ventilation/air flow will increase the concentration, accelerating the rotting process.

More generally speaking, keep in mind that “rusting” is caused by acids: the metal reacts with the acid, becoming a salt (and usually releasing hydrogen). A lot of common substances have acid PH or can release acids under specific conditions. Let’s at least try to not store the minis in wooden cabinets or boxes, avoiding cold and/or damp places.

 

SOLUTIONS?

To restore the miniatures affected by lead rot is important to remove the oxidation layer and all the “converted” metal. Then, if the damage is severe, it will be possible to restore parts by reattaching them with standard procedures, filling holes and crevices with putty and doing some re-sculpting, if needed.

So I started doing some testing and research…. Removal with “manual” methods is difficult at best, it’s easy to damage “good parts” and almost impossible to completely remove the oxide.

So I started asking myself: how do archaeologists do? I read some articles here and there and the solution seems to be almost always the same: electrolysis and, more specifically, electrolytic reduction! That’s not hard, it’s easy to setup and the required equipment and materials are relatively simple to salvage or acquire.

Electrolytic Reduction - a minimalist setup

Minimalist Setup

After some more articles, blogs and books abstracts, I started thinking about some changes for adapting the process to our small friends: we need to work primarily on pewter and lead alloys and very small volumes, so this is what I used:

Small Plastic Container, better if with a lid or cover that could be cut and adapted to keep the “electrodes” in place, it’s important they don’t touch each other. This will contain the solution and the electrodes (miniature and anode/s)

Demineralized Water for the solution(we don’t want water containing substances that could modify our chemical reaction)

Sodium Carbonate, Na2CO3, for the solution too. You can commonly found it as washing soda (irritant for the eyes, better not to touch it too much with bare hands). It’s also possible to obtain it by heating baking soda, I still haven’t tried it, since it’s so cheap and common, however there’s plenty of resources if you want more info on that…

DC Power Supply, to induce the chemical reaction. Remember, it must output DC, direct current, NOT household AC (that is completely useless for our purposes here)! 12 to 24 V, more are probably worthless, less works too but they will take a bit more time.  If you want to speed up the process it’s better to use a power supply able to withstand 2-3 Amps of current continuously, however smaller currents are working too (100-200 mA), they just take longer if there’s a lot of oxidation to remove. The better solution here is, at least for me, a standard PC power supply.

Old AT power supplies have a nice switch to turn them on, while today’s ATX can be easily powered on by shorting (if your’s standard) the green cable from the main power connector with a black (ground) one. If you plan to use it for other purposes (nice for electronics projects and some less-sane stuff) you can convert it permanently to a sort-of lab power supply (plenty of info on that too).

Crocodile / Alligator Clips or some other cables, to wire the power supply to the electrodes. If you stay on the upside of the 3 A range it’s better to have a decent diameter to not overheat them, the smallest cables used for electronics experiment are too thin. It’s also possible to use more cables in parallel.

Multimeter / Amperometer if you want to check the current flow.

Larger Container with Water, an old Toothbrush, and possibly some Soap. Those are useful to rub away paint remains or similar stuff from the miniatures after the process, if the current is high enough the paint will be nicely removed with the oxide. The toothbrush can be any kind of small-scale brush with plastic bristles, not too smooth.

Acetone or some other extremely volatile, water-miscible liquid that doesn’t leave residues. I usually immerse shortly the miniatures in it, after the process and the manual cleaning, to remove any moisture left. This is another possibly irritating substance it’s better not to touch too much, plus its vapors aren’t good for the respiratory system and are highly flammable.

Anode, the electrode (or electrodes) that will be connected to the power supply’s positive pole (in an electrolytic cell the anode is connected to positive voltage, to attract negative ions, while the cathode is connected to the negative pole, to attract positive ions).

Here the material the anode is made of is very important, because the chemical reaction will rust it and alter it quickly. If you don’t have some spare solid gold or platinum, the best alternative is a carbon rod (graphite), it will last long and the only collateral is the deposition of some carbon particles on the minis. Another alternative is stainless steel, but the reaction will produce small amounts of very bad substances (possibly hexavalent chromium), so I don’t recommend its use. Carbon rods can be bought for science experiments or on Ebay, salvaged from motors (brushes) and from some batteries (zinc-carbon), also some large mechanical pencils use thick leads that are practical for our purposes.

Carbon rods after a few hours of use as anodes

Carbon rods after a few hours of use as anodes*

 

THE PROCESS AND SETUP

Setup isn’t so complex, the miniature to clean will act as the cathode, thus it must be connected to the negative pole of the power supply. The other electrode is the anode and it’s connected to the positive.

They’re immersed in the solution: 5-6% (in weight) of sodium carbonate in water (stir it).

Important things to keep in mind:

-Be sure to have the minis connected to the negative (-) pole of the power supply and the carbon rods, or whatever conductive material you’re using as anode, to the positive (+) pole. If the polarity is inverted, the minis will get oxidized and damaged.

-Be also sure the anode and cathode never touch: that will short the circuit, causing a very high current “spike”, damaging the power supply, or the anode, or the cathode (you miniature), possibly all of them! For this I use some kind of plastic “grid” or spacers over the solution container.

Solution container with cathode and anode support and spacers

Solution container with cathode and anode support and spacers*

-If you want to monitor the current flow, the amperometer or multimeter must be connected in series to the load (so the current will pass through it while working the “circuit”), so use it as part of the cable going to the anode OR to the cathode. Don’t connect it in parallel to the load (our solution), it will short the circuit, probably destroying itself.

-The current flow it’s important, having an high current (2 Amps and up) will heat all the elements, make the solution evaporate faster, etc. If you don’t have a current-regulated power supply (most aren’t), a good way to control the current is by immersing the anode more or less in the solution. Less surface immersed = less current flow (the conductive area is smaller).

-I recommend to keep the cathode (your miniature) completely immersed in the solution during the process, that will keep the oxidation removal uniform. To do this it’s possible to use a metal clip that will get partially immersed in the solution. Remember, the current must pass through the miniature, so there has to be an electric connection from the negative pole of the power supply, all the way to the miniature itself. Metal cables and clips/clamps are the easiest way to obtain this. Just choose something that will not exert a too strong force on the miniature, damaging it!

A clamp for using the miniatures as cathode

A modified clamp for using the miniatures as cathode*

-It’s possible to use multiple anodes to have a higher current and/or to have the miniature cleaned faster and more uniformly. This can be achieved by placing the anodes equally spaced and at the same distance from the miniature. A tube- or ring-shaped anode can also “contain” the miniature and be connected in different parts to the positive pole of the power supply.

-The time it will take to clean a miniature will depend on a series of main factors: current intensity, miniature and anode/s total surface, oxidation depth. Usually 2-3 hours are enough for most pieces and 1-2 A currents.

 

SOME AFFECTED FIGURES AND THE RESULTS

Depending on the manufacturer, different alloys are used in the production of the miniatures, some of the most affected seems to be old Grenadier’s figures and Citadel from the 80s. I’ve personally opened a perfectly-preserved 1983 Grenadier shrinkwrapped box, and found a figure (and only one, lucky me!) affected by a bad lead rot case…

Here you can see some different minis and the results obtained


In the next article I will examine more miniatures that underwent the process, the results are generally good, cleaning is complete and in-depth.

For the worst cases , where oxidation is actually keeping together the parts,  I will do some more experiments with changes on the amount of electrical current and type of solution used, I’ll write an article on that when I’ll have extensive data… I will also do some further research on some materials that can be used for the practical restoration of the miniatures (apart from the standard green stuff and epoxies).

Let me know in the comments if the article was useful or interesting, you can also subscribe to get notified when new articles are published!

 

*the white stuff you see in the pictures is washing soda, left by the solution after evaporation.

I’m offering a miniatures cleaning and restoration service, in case you’re interested.

Part two here

Copyright © 2015-2016 Francesco Perratone

 

Further readings and research:

– Metal restoration and electrolytic cleaning –

http://nautarch.tamu.edu/CRL/conservationmanual/File14.htm#ELECTROLYTIC%20REDUCTION

http://www.metaldetectingworld.com/control_voltage_current_p23.shtml