Thursday 22 August 2013

Stopping the rot

These are, I hope, two command figures for the 2nd Regiment of Grenadiers of The Guard. I say ‘hope’ because the drummer and flag-bearer are both suffering quite a bit from lead rot. This is an occupational hazard when trying to create a wargames army with figures that are sometimes up to 50 years old.

Now I am no chemist (ungraded at ‘A’ level – quite a feat!) and I know we’ve touched on this topic before on this blog but, as far as I can make out, lead rot is an oxidizing process possibly helped along in this case by the figures being dunked in chlorine to remove the old paint. Mostly the metal just looks a bit tarnished but in places there are deposits of a white powdery substance.

In the past my remedy has been to brush off the powder as much as possible and then basically ignore the problem and apply a black enamel paint undercoat as usual thinking that once the figure is sealed it will stop any further oxidization. However, this kind of thinking (rather than taking a scientific approach) may be just the reason that I got that ‘ungraded’ result, so do any of you boffins out there have any other suggestions?

8 comments:

MSFoy said...

The effect of bleach, as you have described very well before, is a bit scary. Too long in the bleach and the pale, crystalline coating appears - which can even blur the casting detail a little. Getting the period of soak correct is critical. I've given up on the resoak to remove final traces since I don't judge it well - the bare metal can deteriorate faster than the remaining paint - but that is my lack of understanding, I think.

Another interesting effect comes if I leave a part of a figure sticking out of the bleach (i.e. in the air, or at least in the chlorine fumes above the bleach) - it turns a vivid navy blue colour, or black. Of course I do not understand the chemistry, but since I am not sure what metals are present in the alloys the whole thing is an unknown.

I believe that alloys used in castings vary according to the age of the figure, the maker - all sorts of variables. What the crystalline substance is, what the blue stuff is, how stable any or all of these are - any guesses?

I haven't had any discernible rot on figures - things like deterioration of ancient Humbrol clear varnish have been a much bigger problem with my old soldiers - but I keep a wary eye on them.

When I was a nipper I had some pre-war Britain's and Johilco figures which may have been actual lead (they were ancient hand-me-downs), and they just crumbled into bits eventually. That's a scary image, but probably not relevant to the figures we use now.

This comment is far longer than I intended - you must have got me anxious!

Here's to a rot-free future - cheers - Tony

Stryker said...

Hi Tony

Thanks for the comment and sorry to cause such anxiety!

I generally avoid a second dip too but sometimes (as in this case) I just can't help it. I knew I shouldn't have done it...

You are right of course about the varying quality of alloys used. In this case the flag-bearer is unlikley to be a genuine HH figure as the metal is light and both the base and figure are thin but it is the only casting of the type that I have.

If I'm lucky I have another 20 years or so until my sight is such that I will not longer be able to enjoy these figures so as long as the rot keeps at bay that long it should be ok!

DC said...

As i understand it soaking in bleach cures at least one type of rot, and it's the chlorine in the bleach that stops the damaging chemical reaction. After a couple of days soaking rotten areas appear dark brown or black and can be scraped off. Painting over an area of rot won't prevent further rot as it's effectively a chain reaction, you have to intervene to neutralise the reaction.

It seems to be pot luck with figures - i've had some new figures (Rafm when cast in the UK by Portage) rot within 12 months...and that under my best paintjob...8-( but then i've bought 40 year old figures that seem untouched. That said, i've stopped buying second hand Hinchliffe from fleabay unless they are either painted, or the photos are good and show the castings to be bright and shiny - i've bought too much rot in the last couple of years.

Incidentally, apart from impurities in the metal (see Portage above, gggrrrr...) environmental conditions seem to be the main factor - cold, damp conditions should be avoided obviously, and some blame acid emitted by PVA, cardboard and hardboard/MDF for triggering the rot.

These days my rule of thumb is that if a figure is obviously crumbling (bayonets seem to go first) or has areas where a rough white substance has replaced the alloy then i bin them, otherwise carry on regardless.

Hopefully the above is accurate (where's the wargaming chemist?), and won't encourage further paranoia. Cheers.

Stryker said...

Hi DC

Thanks for your comment - I like the idea that the chlorine may actually be helping the situation. On the other hand I do have one or two figures where I have painted over the rot so may now have sleepless nights worrying about chain reactions going on beneath!

On the plus side - in my experience - the alloy that Marcus Hinton used seems to have been pretty good. I've stripped quite a lot of vintage HH figures and only ever found one really dodgy one.

I'm hoping that Rafa (Project Leipzig)will post a reply as he may be our wargaming chemist!

Michael said...

I have been following your blog now for several months and have greatly enjoyed your project. I have been collecting old 54mm toy soldiers and wargames figures for most of my life and have encountered the "rot" problem before. It used to be called "lead disease", but it is definitely not infectious to other figures. It is not generally encountrered in modern castings because of the high quality alloys used and in older castings it is usually because of the higher lead content. It is as you thought a kind of oxidation of the metal and is usually caused by environmental factors such as cold and damp. In my experience, by removing the oxidised surface (be careful as it is toxic) and by a combination of good priming (enamel paints are excellent, or you could try a Halfords car primer which are designed to protect metal from oxidation), and proper storage, allowing air to circulate around the figures, you should have no further problems. This problem has plagued many a vintage toy soldier collector and has given birth to many urban myths in the toy soldier press over the years, but the experts and museums tend to follow the above advice. Another problem which seems to accelerate or indeed start the problem can be direct contact with oak as the tannic acid given off is a known contributer, and I have my doubts about MDF as this releases formaldehyde. Best Regards M.

lewisgunner said...

When I cast for him Hinton used two types f metal, both from a company called Fry's.
One was KA , the other C . I think C was more brittle and only really suitable for bigger figures. The ideal was KA which was like a form of plumber's older. That is the more malleable metal that ou get HH in. Of Ouse HH were not making or 50 years hence and did try other metals.

The worst ever period for metal figures was the 80s and 90s when anufacturers went cheap with metal containing Bismuth. I had some Ral Partha Landsknects that broken half after a few years. However, I am not sure that was lead rot, just the unstable Bismuth alloy. Also mixed in the metal was printers metal. This contained Antimony which gave it high definition , but made it very brittle. A manufacturer called Freikorps/platoon 20 who produced stuff that broke if you dropped iabase on the floor used printers metal extensively. I have some HH pirates in this metal, they haven't rotted, but. Are veryf fragile, especially where a musket joins the hand.
As to lead rot, if you get it best throw them out!
A search on Google for Lad Rot should get you o sme of the iscussions about it that have been on the web over the years.
Roy

lewisgunner said...

http://theminiaturespage.com/boards/msg.mv?id=301696

For a discussion of lead rot

Stryker said...

Michael - thanks for the comment and glad you're enjoying the blog. The car primer is a good idea and your comments about storage are interesting too. Most of my Hinton Hunts are kept in my display cabinet which allows air to circulate but I do also tend to use 'lockable' plastic boxes which may not be such a bright move!

Roy - interesting stuff as usual. I always wondered why Freikorps used to cast there 15mm's in that awful brittle metal now I understand!