How to stop lead rot?

[vikotnik]

Does any of You guys know a safe and reliable way to stop lead rot?

I have quite a few OOP figures in my collection and discovered that some of them begin to deteriorate.


Any ideas/links?

[pixelgeek]

What about cleaning and then priming them?

[Hammers]

Lead rot is a salt which appears as blooms on high lead content miniatures(+75% and therefore VERY rare in modern minis). Apparently the environment they are kept in matters a great deal.

Humidity and tannic acids (as in oak) seem to be the main culprits but it can happen anyway.

Remedies are good primers between metal and paint plus several layers of varnishes.

[Prof.Witchheimer]

Remedies are good primers between metal and paint plus several layers of varnishes.

agree, that should help

[gilibran]

found this on my harddisk... :mrgreen:

here are some thoughts taken from a report of the curator of navy ship models http://www.dt.navy.mil/cnsm/lead_01.html
(following the link to their site will give you the full report with some perhaps scarying results):

as a result it is quite clear that lead rot is caused by a chemical process:
acetic and some other acids, in the presence of carbon dioxide, catalyze with lead to produce lead acetate and lead hydroxide. lead acetate and lead hydroxide together react with carbon dioxide and form lead carbonate. lead carbonate then releases acetic acid and the process becomes self-sustaining. it is important to recognize that the formed lead carbonate is not just a substance clinging to the surface of a casting, it is the surface of the casting transformed to powder. for practical purposes, a portion of the lead is gone and lead carbonate is left in its place. the lead carbonate releases acetic acid which can continue the process until the lead part is progressively consumed from the outside, inward.
this chemical process benefits from wood and/or acrylic sheets in your display cases, so avoid these...

so far for the scientific part...
but what can you do with a miniature that has been caused by lead rot ?

first of all you have to clean the miniature, obviously...
this can be done by using a short soak in white vinegar followed followed by cleaning the miniature with a toothbrush with toothpaste. an electrical toothbrush might be very helpful here...

for heavily affected areas you can use a dremel or something similar with a cleaning and/or polishing bit. check out their site for their different brushes at www.dremel.com.
do not forget to let the miniature dry on a paper towel or use a hair dryer thoroughly !!

after cleaning and before (!) any repair, conversion and painting work you have to prime the miniature. do not use any water based primers/paints for this. the best way seems to use a polyurethan (PU) paint because this will seal the miniature hermetically. you can get this paint in any colour and even clear, if you prefer to display your miniatures in bare metal form.

As a final note there seems not the same problem for the white metal miniatures that are available nowadays. but who knows, only time will tell...

[vikotnik]

Thanx for the very interesting link, Gilibran!

I have bought a bottle of PU paint and will try out to clean a figure with vinegar this evening.


Hmmm... one of the substances causing lead rot seems to be PVA glue, the stuff I use on almost all of my bases...

[gilibran]

As hammershield pointed out already, this disease effects older miniatures only.
Roughly miniatures before 1990 might be affected.
Perhaps you remember the changed laws in the US, as the miniature industry was forced to change to "white metal"...
I have quite a lot of pre 1990 minitures but not one has crumbled into dust, but I have heard worse things from other collectors.
Admiral Benbow has lost one of his dioramas by this...

[Admiral Benbow]

Admiral Benbow has lost one of his dioramas by this...

That's definitely true, unfortunately  :cry:

A good part of my miniature collection comes from Citadel's releases through the eighties, both from their own and licensed ranges like Ral Partha. In the last years I have thrown away about 100 figures which have been destroyed beyond any repair. And you will not get a guarantee that a figure is save even when it is fully undercoated, painted and sealed with polyurethane gloss coat! The latest victim is my Ral Partha Imperial Dragon (linited edition of course   ) mounted on a diorama base, which has been repaired half a dozen times with additional coats of gloss laquer.
The reason for all this annoyance is just that Brian Ansell of Citadel fame wanted to save some money on production costs and changed the alloy for Citadel minis to a heavy part of lead instead of tin or antimon. There is a quite detailed report on this from one of the that time Citadel casters on the Frother's page in the "Archive Citadel Miniatures" thread, but I'm currently too lazy to look through 180+ pages again (yes, I did it once, and this thread is one of the most interesting ones on the net concerning the history of the little tin - or lead - men you can find). If you would like to have a look:
http://www.frothersunite.com/phpBB2/viewtopic.php?t=4827&postdays=0&postorder=asc&start=0

Anyway, Vikotnik, an airtight seal with polyurethane gloss laquer will be the best way to prevent the minis from rotting. As many I've lost, there were quite a few I could save without showing the lead disease again.

[gilibran]

In addition to this topic here is a guideline how to avoid own diseases caused by working on lead miniatures:

http://www.lead.org.au/fs/fst25.html

Does anyone care about them?  :lipps:

[Argonor]

Hmmm.... lots of advice, I've never followed.