Zinkpest ? for Frank H !

[Jan Arne S]

Hi Frank !
I read in a other thread that it possible to use "vaseline" to stop or reduse zinkpest .
Is that the same "vaseline" that we have in Norway , yellow in yellow small round bokses .
More known from other aktivities than badge collecting

Thanks in advance !

Lillegutt

[Frank Heukemes]

Dear Lillegutt,

Yes, there is just one vaseline! But make sure you use unused Vaseline, ok?

Seriously, leave it on the badge for a couple of hours and watch the badge frequently. It should not damage the badge in any way, but just to make doublesure. There should be no problem and you can leave the vaseline on overnight. It takes some time for the zinkpest to dissolve. Then wipe away next day. You might clean the badge afterwards under lukewarm water rubbing it gently using acid free soap. Removes the gloss from the vaseline.

As always.....use on your own risk. But this is one of the less risky things one can do to badges and....well you get it.

Cheers, Frank

[Tony Barto]

Frank;

Does this treatment actually stop the advance of zinkpest??

[Frank Heukemes]

Dear Tony,

Yes, it removes the white crud and should prevent it from building up again. But one should check regularly, even after that treatment. Of course, any damage already done, like pitting, is irreversible. But if you see it just starting out or if you want to stop the process, it is ideal IMO.

Cheers, Frank

[Tony Barto]

Thanks Frank!

[don]

Can someone give us some information on Zink pest?
What it is and how it forms?

don

[Jan Arne S]

Hi Frank !
Thanks for that info about Zinkpest .

Lillegutt

PS ! It`s cold in my part of Norway this days , -23*C Monday morning .

[mgidhagen]

Zinc Pest - lead corrosion

As far as I have understood it, zinc pest is roughly the same thing as lead corrosion - and here is a link to what that is...
http://www.dt.navy.mil/cnsm/lead_01.html
Have not heard any comments on this site, though...
/Mike G

[anguspm]

Ok All,

Whilst not being an expert on badges and militaria and the problems inherrent I may be able to give a little background on "zinc pest" as its been called.

Background: I work in aviation engineering and there are two things an aircraft designer wants from a material: strength and minimal weight. Aluminiun/Zinc/Ceramics and Composites all have these attributes. It therefore follows that zinc is used in the casting of such components as gearbox casings.

Zinc corrosion: Zinc reacts to hydrogen by producing an endothermic (gives out heat) reaction. The residue of this is the fluffy white deposits you see on your badges (cant remember the chemical name for the deposit). This is in much the same way that Iron reacts to H2O to give rust.

Prevention: Zinc as a metal is fine if it is sealed from the atmosphere (paint/laquer etc) or kept in a humidity free environment.

Conclusion: For just about all of us it is impossible to build a "dry-room" or move house to death valley california (lowest humidity in the world?) so there has to be an alternative.

a) If you are one of those who likes to handle the badges on a regular basis then the application of vaseline will seal out the moisture from the badges surface. Just remember to check that the vaseline isn't drying out and letting the air and therefore humidity attack the badge. This is much the same as spraying the bottom of your car with oil before winter driving.

b) If you can get by without touching the badges put the into a frame or box that is sealed with a silica gel/ desicant pack. The desicant will remove the moisture from the atmosphere you've trapped. So preventing the decay.

NOTE: If your badge has its original paint remaining it will be sealed against the air and humidity so niether of these actions is necessary.

CAUTION: Using vaseline is a temporary measure that seals the badge. If removing it use alcohol (100% proof) as washing a badge in warm water introduces the agents that will attack the badge.

Hopefully I've managed to enlighten you guys as to how zinc corrosion happens in the same way that you have educated me with regard to badges and medals.

As a footnote to those who wish to wash zinc badges in water I have seen a helicopter gearbox pulled from the sea off Serbia that had been submerged for two days and all that remained were the titanium gear teeth!

[Tony Barto]

Hi anguspm;

Thank you for the information. I was really surprised to read that zinc reacts to water in that way!!

[anguspm]

Hi Tony,

The reaction you get between magnesium and water is violent and taught in british schools (petri dish with the magnesium ribbon flying around whilst "burning"). Zinc has the same properties but the reaction is not as violent and takes longer. This is off course "pure zinc" but mixing it with other metals (alloying) will slow the process not stop it.

The reason the helicopter gearbox was destroyed was any "zinc pest" that formed was washed away by tides/currents so exposing a new piece of bare metal. A "ground-dug" badge looses the outer details to "zinc pest" but the zinc pest then seals the badge against the attacking elements effectively forming a protecting layer between the two.

"Zinc cladding" is a seperate process used as an anti-corrosion method by alloying the zinc with another metal so that exposure to the elements causes the zinc to react and form the protective layer keeping the metal of the structure free from corrosion.

I'm sorry if this bores anyone its just that corrosion is the biggest killer of airframes and we are always trying to find ways to remedy it.

Respectfully

Angus

[keifer kahn]

I think its fascinating.If its relevant to our hobby then im interested.Thanks for the info!
I have 3 ground dug zinc IABS.A silver unmarked F&R tank badge.A midwar unmarked zinc wound badge.Also a severely corroded midwar ss officers buckle in zinc.all of these have zinkpest.Ranging from the powdery form to the hard crystalized form.The colour varies as well from white to a mushroom gray(in the crystalized form.

Is there any reason for the varying types or levels of zinkpest?

Is there any reason why the wartime zinc badges seem to exhibit zinkpest a lot of the time and modern repro zinkers dont seem to get it?
Once again i find this fascinating,

regards keifer

[IVAN]

Thank you Angus,

great informations!

Ivan

[anguspm]

Hi Keifer,

Its difficult to explain why some badges will corrode (thats what zinc pest is in effect) more than others without doing a chemical analysis of the metal itself. But in general terms i'll attempt to provide some answers.

For each badge any one or all of these factors can apply;

a) Original metal the badge is constructed from: there can be all sorts of variations as to what metal the zinc has been alloyed to and in what percentage. This is why the zinc pest takes on different forms from bright white to dull grey.

b) Quality of the finish: If a badge is effectively sealed by the paint wash applied and has this finish remaining when buried it would show alot less ageing than one that was worn at the time of burial.

c) Type of soil buried in: For example a badge buried in clay would corrode quickly due to the water retention properties of clay. At the other end of the scale frozen tundra would stop most water getting at the badge.

d) Use of the soil badge was found in: For example a badge found on a western european farm would probably have been subject to attack from chemical fertilizers. The opposite being true of eastern european farmland.

Summing up:

The four reasons listed are the primary factors in the different rates of corrosion. Others also exist to a lesser extent eg: handling once the badge is retrieved etc. If you think of different types of bread and the way in which they grow mold in different conditions then you can why badges decay at different rates and in different forms.

If there are any more questions or a point I've failed to explain ask away.

Regards,

Angus

[skip]

A really facinating thread Angus, thanks very much for the info.
I remember doing that experiment at school but never connected it in any way to badges.
I personally always seal ground dug badges with clear artists varnish, and have found this to be the best method of preventing further decay.
Angus I have heard people say that you should not store badges with zinc pest togeather with other badges as it may "jump across" onto the other ones. What do you say to that?.

Skip