Rusting pins

[Silent Surrender]

Hey all. I recently discoverd that the wire I use to pin my models are prone to rusting. Could this in some way damage the paint job or the miniature in the long run?

Thanks for any replies!

[Spiney Norman]

I'm not sure how your pins would rust when they're inside your model, unless you make a habit of regularly immersing your minis in water I think you should be fine.

[Yrrdead]

Only tangentially , and by that I mean that it is possible for a rusted pin to break more easily and the resultant damage from a break and or falling to the floor.

But other than that there shouldn't an issue.

Also another reason to look into brass rod as opposed to other pinning media.

[drear]

you must be keeping your models in a damp shed for them to rust o.o or are you dipping them in salt?

id sugggest getting brass rod as mentioned abouve, and keeping your models dry and clean

[Yrrdead]

I didn't even think about how they were rusting until I reread what you guys said.

I've had paper clips sitting next to my phone for at least 10 years with zero rust so now I'm really intrigued by how his pins are rusting. Especially if you consider they are sealed first in super glue than base coat than paint. How is oxidation occurring? This thread just became awesome.

[Bodysnatcher]

Potentially the presence of green stuff could accelerate rusting. As could two components having come from significantly different batches of metal.
However it's unlikely that it'll get bad enough to weaken the joint to dangerous levels.

[Urgat]

you must be keeping your models in a damp shed for them to rust o.o or are you dipping them in salt?

id sugggest getting brass rod as mentioned abouve, and keeping your models dry and clean

How'd he even know the pins are rusting unless he cracks the models open, silly?
I suppose he means the reel of wire shows marks of rusting. I assume that inside the model, this should not happen, or if it does, it'll be so slow you won't see the effects during your lifetime.

[Silent Surrender]

Im using iron wire that is 1,2mm thick. I noticed that it has rusted when I had a piece of it laying next to my paint water which I must have spilt some of onto it.

I dont know how rusting works thats why Im asking. So a wire enclosed in super glue or green stuff will not be able to rust?

[Kurisu313]

Im using iron wire that is 1,2mm thick. I noticed that it has rusted when I had a piece of it laying next to my paint water which I must have spilt some of onto it.

I dont know how rusting works thats why Im asking. So a wire enclosed in super glue or green stuff will not be able to rust?

Rust is Iron Oxide - it requires Iron, Water and Oxygen to be present to form.

[Thommy H]

Rust is iron oxide: iron will rust only if it oxidises (i.e. is exposed to oxygen). So iron objects will rust if left in the open air after a significant time period (because there's some oxygen in the atmosphere, but not that much proportionally) and more quickly if immersed in water (because water is a third oxygen). An iron object left outdoors will eventually rust due to exposure to the elements.

But an iron pin inside an miniature won't rust because it isn't exposed to the air. And unless you immerse it in water and there are significant gaps in the model for the water to penetrate, it won't rust from that either.

So don't worry.

[Silent Surrender]

Allright thanks all! I was worried the paint job would be ruined in a coupple of years or something but i feel much better now!

[daboarder]

SO MUCH BAD CHEMISTRY!!!!


"rusting" is an electrochemical reaction that occurs between 2 metals that have different electrochemical potentials....happens to everything really. It involves a redox reaction as in one of the metals is "oxidized" please not this does not mean that the reaction requires oxygen it means that one of the metals is losing electrons.

What I'd say is that the paper clips your using have to much zinc in them and this is reacting with the tin in the metal mini's. Most paperclips are galvanized but If yours aren't or their scratched this could be happening.

And yes it could end up ruining your paint job I wouldn't worry about it though not much you can do.

[Kadris]

Short answer, it might.

However its a mute point. If is a concern, use something else to pin with like a galvanized material or one that doesnt rust (i use some paper clips that are electro plated or something). For any models that are already pinned with your material, its too late. If it damages them there is little to do about it but fix it when it does and if it doesnt then it all turns out ok.

Its not broken yet so dont fix it, but change what you use so the chances of something breaking is less.

[daboarder]

If is a concern, use something else to pin with like a galvanized material or one that doesnt rust (i use some paper clips that are electro plated or something).

haha, that's the same thing, two names for one technique, but you have a point regardless.

[Freakiq]

Aren't most paperclips made of brass anyway?

[russellmoo]

@daboarder- I actually did not know that that was how rust was formed- man the things you can learn on warseer-

[Yrrdead]

Well in this specific case he isn't correct as the OP specified that he's using iron wire which follows this corrosion mechanism which doesn't require the presence of another dissimilar metal.

[daboarder]

OP stated that it was occurring at a joint between 2 different types of metal making it far more likely that it is occurring due to the different chemical potentials.

Of course that redox reaction above is entirely possible but its unlikely that the paperclips are plain iron as nobody really uses Iron except in alloys of some form any more.
See on that diagram where it mentions the cathode and anode, give that the pin is not exposed to air means that the likely situation is one metal (in this case the pin) is acting as a cathode to the others anode.

If its Iron pins it would make sense as it is more reactive than the tin in the white metal as per the reactivity series.

In other words:
Fe => Fe2+ + 2e- and
Sn(II) +2e- => Sn


If you want to Be really specific that diagram you post IS a redox reaction between two different metals, IE: 2 different species of Iron, the water merely facilitates the reaction but is most certainly not necessary.

@daboarder- I actually did not know that that was how rust was formed- man the things you can learn on warseer-

Cheers mate, recently became a qualified chemist, fun to put knowledge into application.

[Tomalock]

OP stated that it was occurring at a joint between 2 different types of metal making it far more likely that it is occurring due to the different chemical potentials.

The OP does not say that in any of his posts. In his first post he only mentioned that he discovered his pinning material was prone to rusting, never actually stating that it was rusting after he pinned his models. In his next post he clarifies how he made that discovery. You should go back and actually read what Silent Surrender said:

Im using iron wire that is 1,2mm thick. I noticed that it has rusted when I had a piece of it laying next to my paint water which I must have spilt some of onto it.

[daboarder]

Hm fair enough, in that case its likely that H20 vapour is reacting with the Iron.