In response to my post about the 20 year old Matchbox Panzer III (next up here at the Hobbit bunker), DaveM brought up the issue of perished tracks in old kits. He says:
'Further to your comments about long term kit storage. I've never had too much trouble with really old decals. Sometimes a bit of yellowing but this can often be cured by a good dose of direct sunlight. But I would recommend storing them separately from the kit. And I would also advise storing vinyl and rubber tracks separately or at least isolating them (eg in polythene) from the rest of the kit. One theory is that some of those batches of Matchbox kits (eg M16) where the tracks disintegrated in the box was due to interaction between the tracks and residue from the mould ejector medium on the plastic parts of the kit.'
These interesting points brought to mind a 'First Principles' column written by Bruce Quarrie in Airfix Magazine in the early 1970s. I sorted through my small pile of those classic magazines, and found the article, which was, amazingly, on the same page as the Terence Wise article about Airfix engine shed conversations which I pictured just a few posts ago! Anyway, what did Bruce Quarrie have to say 42 years ago:
'After two or three years a reaction frequently sets up between the plastic in which an Airfix tank kit is moulded and the flexible tracks. This reaction in due course actually "melts" the plastic from which the tank's wheels are moulded and, of course, ruins the model [...]'
Quarrie went on to recommend varnish before painting tracks and wheels, body etc. What is interesting here is that the problem seems to be manifest in disintegrating wheels, rather than tracks. Now, happily, I took Quarrie to heart all those years ago, and suitably sealed tracks and running gear, so none of my AFV survivors from the early 1970s shows any sign of decay. But did others experience melted running gear?