"Corrosion and Steel washers (A Warning)" Topic

I like a lot of folk use steel 3/4" ED zinc plated washers to base my 20mm Figures and base using PVA Glue and beach sand. With a lick of paint and a few tufts of ground foam it looks a treat.

HOWEVER…. One day I found myself rebasing a figure and noticed corrosion (rust) on the base underneath the figure.

After looking at a few examples it seems to occur where the gigure comes in contact with the washer, particularly if the figure isn't completely primed. Hey, you miss bits, I'm not without my faults!

I presume this is possible in any adhesive system that can act as an electrolyte (water based), will do this to some extent.

I suspect if you completely break the contact between the figure and the base, then it won't occur. two peices in metal in an electrolyte in a circuit = an electrolytic cell

As any engineer will tell you electrolysis is "Bad News" for corrosion, including the dreaded "lead rot" (GASP)!

It doesn't seem to happen with plastic figures based in the same manner (not suprisingly).

I'm Not sure on a solution except maybe placing plastic between the base and the figure. and being dilligent about priming both the base and the figure.

Cheers.

Ooh cripes, excuse the typos…

I hot glue to bases, I assume and hope that this would prevent the avove ?

So, that thin metal sheet basing I have been using is probably bad too.

Not good news to hear, but thanks for the notice.

Its possible that the steel will act as a sacrifical anode, though I havent looked at the appropriate literature.

I would suspect that hot glue would act as a insulator just like the plastic I suggested, though only time will tell.

I hot glue too and have not had any problems.

as long as you have no direct contact between the metals then the electrolysis should not occur.

Alternately you can just start using plastic figs. :)

Ouch, this is bad news. I superglue the figure on the washer with superglue BEFORE I prime with Humbrol enamel paint. I have not seen any problems yet. Does any corrosion on the washer automatically start the dreaded lead-rot process?

My question is similar to Travellera's comment. My 15mm WWII figures are glued onto washers with superglue (cyanoacrylate) prior to being primed and painted. Would these be susceptible to the corrosion and lead rot as well?

Is this issue due to the two metals simply being in contact over time, or the fact that they are in contact and also have the water-based PVA glue present?

I use a garage sale sticker on top of the washer, and I glue the figure to that. Have not had problems with that approach in 10 years. Learned that trick from Regiment Games.

I checked the galvanic table & lead & tim are higher up than steel so in theory they should corrode first (just like zinc on galvanised steel will) so bad news.

However my understanding of lead rot is that it is not ordinary oxidation but something more complicated (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) so that may not be an issue. Lead & (tin) have stable oxidation inlike rust which flaxes off to expose more steel to rust thats why lead was used for roofs & pipes. However PVA glue may contribute to lead rot (according to the navy ships website) and its waterbased & acidic nature may be contributing to the rust on your washer also.

Finding an alternative to pva like a hot glue gun for sticking the figure to the washer is realitivly easy but does anyone have a good alternative to pva for adding sand & flock to a base. I think that is what mose people use.

I am not too worried about most of my minis but I am casting some prince august 40mm out of a mixture of printers monotype & lead pipe scrap & I think I will need to be carefull to do everything I can to protect them given the high lead content they will have.

CColins do you live in a particularly humid area or store your minis somewhere humid. I would expect the zinc coating on the washer to protect it for a substantial ammound of time considering it is indoors. Maybe you need to consider stainless washers.

If superglue bonding lead and steel is a problem, wwhat about steel wire wpears?
Or brass spears?
Or, gluing to steel bases.

Yes, while our climate is pretty dry (the last decade has been either drought and very dry years in the south east of australia), our house is a californian bungalo, and water does accumulate below the house now and then.

I suspect the culprit is moisture trapped between the figure anmd the base and galvanic corrosion eroding the zinc layer quickly and exposing the steel beneath resulting in visible rust.

John the OFM: potentially these are all problems, as well as pinning parts together using wire. Its not so much the superglue as the direct contact between differing metals.

Don't consider me an oracle on this matter, I'm just observing recording and reporting what I see.

Sorry to resurrect such an old topic, but was a solution ever found to this problem?

As CCollins stated, it is caused by the differing metals in contact with one another. The only real solution is some sort of insulation between them, preventing contact.

Hot Glue is actually a plastic material, melted in the gun, which cools, and solidifies. For basing, this would be an excellent insulator, assuming no metal pushes through the Hot Glue's molten plastic, to make contact with the washer. A two-part epoxy will most likely work as well, assuming its chemicals won't react with the metals. Hot Glue plastic is pretty inert, easy to use, and paintable, with craft paints. Best of luck. Cheers!

I use coins not metal washers and superglue and hot glue for sticking figures and basetex for basing. Except where I use plastic bases.

Some UK coins are magnetic (though not all) so – if you need magnetic bases, that might be a route to take.

Not seen any coins rust, as such.

John T

I've had that problem in the past and I think humidity and storage location play a part too. Have switched to round wood bases.

Regards,

J. P. Kelly

I use stainless steel washers: has anyone experiened any problem with that type of basing?

Also, is white metal subject to "lead-rot"?