Plastic deterioration (1 Viewer)

[maloyalo]

I am working off memory here, so forgive any technical errors. Challenge whatever sounds goofy & I will get specific details.

Exposure to heat and ultraviolet light (UV) are two clear causes of plastic deterioration. They both degrade plastic similiarly, by exciting the molecular structure and causing electrons to depart, both breaking down and altering the structure. Once this starts, the freed electrons start whacking other molecules and cause more electrons to break free in a chain reaction. Removing the plastic from heat or UV will slow the process down, but not completely stop it. No plastic is usable pure, and all have additives mixed in to give the plastic its desired characteristics. This molecular breakkdown is mainly the destruction of the bonds between the base plastic and its plasticizers. Once free, the plasticizers will naturally migrate away, as fumes and sometimes oily residue that is leeching out of the plastic. A secondary problem then develops as this leaves holes, which air can get in to. Another deterioration process starts called oxidation. I had thought that was only corrosion for metals, but was wrong.

One pretty cool additive that many plastics have is put in as a UV degration inhibiter. It is substance of positive particals that just wait for an electron (which is negative) to become free. When an electron does take off due to breakdown one partical attachs to it, makes it neutral & it then does not start chain reaction. But eventually the particals are all used up, and with nothing to stop the chain reaction, degration accelerates.

 

[kilted vampire]

Oh no Just when you thought it was safe to paint plastic figures

 

[maloyalo]

With one exception, I haven't yet found anything bad associated with painting plastic figures. The exception is using enamel paint on PVC figures. This combo tends to not dry & remain tacky.

 

[kilted vampire]

With one exception, I haven't yet found anything bad associated with painting plastic figures. The exception is using enamel paint on PVC figures. This combo tends to not dry & remain tacky.

I knew there was a reason for acryllics

 

[plasmapulse]

I am working off memory here, so forgive any technical errors. Challenge whatever sounds goofy & I will get specific details.

Exposure to heat and ultraviolet light (UV) are two clear causes of plastic deterioration. They both degrade plastic similiarly, by exciting the molecular structure and causing electrons to depart, both breaking down and altering the structure. Once this starts, the freed electrons start whacking other molecules and cause more electrons to break free in a chain reaction. Removing the plastic from heat or UV will slow the process down, but not completely stop it. No plastic is usable pure, and all have additives mixed in to give the plastic its desired characteristics. This molecular breakkdown is mainly the destruction of the bonds between the base plastic and its plasticizers. Once free, the plasticizers will naturally migrate away, as fumes and sometimes oily residue that is leeching out of the plastic. A secondary problem then develops as this leaves holes, which air can get in to. Another deterioration process starts called oxidation. I had thought that was only corrosion for metals, but was wrong.

One pretty cool additive that many plastics have is put in as a UV degration inhibiter. It is substance of positive particals that just wait for an electron (which is negative) to become free. When an electron does take off due to breakdown one partical attachs to it, makes it neutral & it then does not start chain reaction. But eventually the particals are all used up, and with nothing to stop the chain reaction, degration accelerates.

It's stuff like this that get me worried. I have experienced these forms of deterioration with action figures mostly, but never with unpainted figs.
Basically, everything ages. Paint, figures, the people who collect them.

One of the reasons why I rather buy figures not containing lead.

Something more to get you worried; do a google on dvd-rot.
I've been sweating over that a couple of days myself, but now accepted the deterioration of everything I collect. Ashes to ashes. Dust to dust.

 

[Wraith]

Basically, everything ages. Paint, figures, the people who collect them.

Too true.
I figure that I've deteriorated a heck of a lot quicker than my plastic Airfix figures and at the current rate of deterioration, they'll outlast me by a long run.

Simon

 

[kilted vampire]

Simon some of my airfix are a lot more brittle than you are. So it may be a tie

 

[The General]

I'm hoping that the rate in which I purchase and paint figures is faster than their rate of deterioration.

I do my best to extend their lifetime by keeping them out of direct sunlight and in most cases covered.

I'm hoping that painting them helps to preserve them from UV light.

 

[kilted vampire]

I'm hoping that the rate in which I purchase and paint figures is faster than their rate of deterioration.

I do my best to extend their lifetime by keeping them out of direct sunlight and in most cases covered.

I'm hoping that painting them helps to preserve them from UV light.

Welcome aboard! Mine were given to me by my Dad who had them in a closet for years in the original box. I have noticed some discoloration on the acryllics that I use on the Conte plastics.Tryiny to figure out if this is a case of outgassing from the plastic.

 

[The General]

I have approximately 22 boxes of unpainted 1/76 scale Matchbox World War II figures in a drawer at home.

They were purchased and played with by me sometime in the early 1980's.

The roll call looks something like this.....

5 x American Infantry
2 x British Infantry
1.5 x British Eighth Army*
1 x British Commandos
2 x ANZAC Infantry
3 x German Infantry
1.5 x German Afrika Korps* &
6 x Japanese Infantry

*My mate and I went halves in a box.

All are still in good nick with the exception of the Tan/Light Brown coloured Japanese Infantry which has some sort of yellow stuff on it. I'm not sure if it's a fine powder or some sort of liquid film but it can be removed with a rag.

As I know longer play with them I haven't bothered to clean almost 300 Japanese troops.

I can only assume if I did the fine yellow powder/film would eventually return.

They are the only figures that I have had a problem with to date.

Cheers
The General

 

[thebritfarmer]

So far all my figures are fine (going back to the late 70's early 80's) I do have some vehicles that have wheel melt. This is the reaction between the different plastic used for the hub and the tyre. Now the weird thing is I have 3 tractors all by the same company and made around the same time. Two suffer from this condition and one doesn't. Explain that one

 

[Wraith]

All are still in good nick with the exception of the Tan/Light Brown coloured Japanese Infantry which has some sort of yellow stuff on it. I'm not sure if it's a fine powder or some sort of liquid film but it can be removed with a rag.

As I know longer play with them I haven't bothered to clean almost 300 Japanese troops.

I can only assume if I did the fine yellow powder/film would eventually return.

They are the only figures that I have had a problem with to date.

Cheers
The General

This is a common 'problem' with Matchbox tan coloured troops, both in 1/76 and 1/32, although the 1/32 Afrika Korps and Eigth Army sets seem to be most affected by it.

As far as I can tell, it seems to have no effect on the plastic, other than making the figure look a bit, well, dusty. And yes, it does return. I cleaned a load years back and the powder eventually returns. I can only presume it was down to some colouring agent in the plastic, that over the years, forms the yellow powder.

Simon

 

[The General]

I wonder if I had painted the little buggers would the yellow stuff have come through the enamel paint?

I guess I'll never know now.

 

[eborris]

I've got thousands of Airfix HO figures and I bought them in the early to middle 70's and haven't noticed any of them falling apart or emitting ooze. Of course they have been in a dresser drawer for most of the last 30+ years, did have them out recently and they seemed fine.

 

[The General]

I've got thousands of Airfix HO figures and I bought them in the early to middle 70's and haven't noticed any of them falling apart or emitting ooze. Of course they have been in a dresser drawer for most of the last 30+ years, did have them out recently and they seemed fine.

Like yourself, I have not had any problem with any of my Airfix HO figures just my Matchbox 1:76 Japansese Infantry.

If I can get 30 or 40 years out of my current 54mm Accurate Figures, Imex, A Call to Arms, Italeri, HaT and other plastic manufacturers' A.C.W. troops I'll be happy.

I have painted over 400 pieces (better than store bought quality if I do say so myself) and am hoping that a coating of paint can add to their lifespan.

 

[blaster]

I have a huge collection of Airfix and especially Esci and other makes wargames plastic figures , quite a number of them became brittle whether painted or not. I understand from a friend who used to do injection moulding that sometimes they would reuse the rejected sprues. If so, this leads to potential deterioration.

 

[bromhead]

I have had the usual brittleness with old btitains, some 50s types but not a great deal with others from early airfix to most everyone else,,1960s vintage on.

 

[Deitz]

I have Timpo Swoppets some are brittle, but for the most part most are fine.

 

[Cherilea4me]

I have Timpo Swoppets some are brittle, but for the most part most are fine.

PLASTIC WARRIOR magazine covers this topic in their special 'Off With Their Heads' - a guide to converting and repairing figures.
It's all to do with what was mixed into the plastic aid paint retention and the use of certain oils in the tooling...
Get the above publication to read more.

 

[lancer]

I have several ACW Swoppets that are very brittle. If they even fall over they are likely to break, and the same problem with my ACW Britains Heralds. These are even more brittle than the Swoppets. -- lancer