Does plastruct go brittle over time?

[polybear]

I guess the answer to the original question may depend on many factors, such as:

 

1. Is it genuine Plastruct, or a similar materials?

2. Year of manufacture?  (e.g. did the formula ever change due to the EEC stickin' their beak in?)

3. Solvent or glue used during manufacture of the model?

4. Exposure to other materials or paints?

5. Exposure to sunlight?

6. Exposure to heat?

 

etc. etc.

[sharris]

4 hours ago, polybear said:

(e.g. did the formula ever change due to the EEC stickin' their beak in?)

 

I suspect it was a manufacturing change that led to bendy bananas too. 

[Izzy]

On 13/10/2019 at 12:28, Pylon King said:

I’ve been building power grid structures  using Plastruct/Evergreen for over fifteen years and haven’t noticed any changes .

 

I am pleased you haven't had any issues and hope it remains so for what you have made look very impressive. It might be the liquid glue I used that didn't agree with the Plastruct, I think it was either Mek-pak or Plasticweld ( those I normally have and use). Whatever the cause it was annoying and especially as I have never encountered the problem before. Warping at the odd time yes, disintergration and crumbling away, never. I did use acrylics to paint them ( I have now abandoned their use entirely), perhaps it was a long term chemical reaction somewhere, it's anybodys guess really I suppose. Just hope no one else suffers it.

 

Izzy

 

 

[Les Bird]

Having read all the above, I recently retrieved an Airfix tank wagon that I built decades ago from its storage (the original kit box). It has been in a shed for years with all the expected temperature variations, I half expected it to fall apart but it's as sound as the day it was built.

Edited October 16, 2019 by Les Bird

[andyman7]

On 29/07/2019 at 08:46, 34theletterbetweenB&D said:

Vividly illustrated by 1/72 Airfix tracked vehicle kits. I built a great many of these for supply to hamfisted wargamers, in exchange for cash to spend on model railway product. They were not happy when the styrene track wheels went runny due to contact with the flexible track material; an effect that many here will probably recall.

 

On 29/07/2019 at 11:53, wainwright1 said:

I built many Airfix kits over the last 50 years and do not recall any of them falling apart, although they were mostly constructed using the old polystyrene cement rather than solvent. I suspect that once they were painted it substantially reduced the migration of the plasticiser. I also have many old Tri-ang and other brands of plastic bodied locos, coaches and wagons and do not remember any of then going crumbly or soft. Obviously prolonged exposure to direct sunlight would be likely to cause damage on more than one level, but perhaps storing models somewhere where there might be exposure to some kind of fumes or vapour which might otherwise be considered innocuous might cause damage over a prolonged period of time.

 

On 13/10/2019 at 17:38, TheSignalEngineer said:

I've recently rebuilt a couple of Airfix 16T Minerals I originally built in the 1960s. No problems there. Also still running on new wheels are at least three Ratio wagons, a Starfish (Cambrian?), two Airfix Meat Vans and a Cattle wagon built c1980, a GWR Open C, and an LMS Short Tube plus an Ian Kirk LMS 5-plank of unknown vintage but probably about 40 years old. Conversely, a canal transhipment shed I built in 1980 from plastruct section and styrene sheet didn't survive.

The Airfix issue was specifically to do with soft rubbery tracks or tyres and their interaction with the hard polystyrene parts. Airfix changed the formula for the tracks in the 1970s to avoid the issue; before then, the only way to avoid problems was to seal the plastic with a coat of dilute PVA or similar. Airfix kits seem to survive pretty well, I have models and kits dating back to the 1950s in good condition.

As various posts have suggested, this is an area of emerging knowledge. I suspect in about 800 years time we'll have a better idea of the relevant lifespan of various plastic compounds (although I suspect it might be a banned substance by then). From my experience, there are variations in the stability of plastics even from the same item stored in the same way. Then there is yellowing of white plastic or clear acetates - as a Dinky Toy collector, the variety of conditions that (originally clear) vacuum formed 1970s bubble top boxes have ended up is extraordinary. Back in the late 80s there were examples that had yellowed badly in 15 years, others have started to yellow but only over much longer periods and some are still perfectly clear. Once yellowed they become much more brittle and when sent through the post by unknowing sellers often shatter. I wonder how many of the 'block of ice' inner packing pieces from Hornby/Bachmann locos will go brown in the next 30 years.

[wainwright1]

I would just mention in passing that one of my club colleagues recently built a replacement Ratio signal for a club layout. The kit was moulded in white and  black plastic parts. The white parts were fine, but he found that it was impossible  to cut the black plastic parts from the sprue without them shattering. Luckily he was able to replace the cranks etc with brass ones and was able to complete the kit. So problems with plastic are not a thing of the past.

 

RB

Edited October 17, 2019 by wainwright1
word missed out

[sharris]

19 minutes ago, wainwright1 said:

The white parts were fine, but he found that it was impossible  to cut the black plastic parts from the sprue without them shattering.

 

I had the same problem with thin parts on Ratio black plastic coach bogies. Some of the brake levers on Ratio's LNWR wagons (grey plastic) also turned out to be very fragile.

[TRAILRAGE]

Not just Plaststuct and kits either . I've had 4 Lima B/G Powercar bodies shatter when picking them up rendering them beyond repair.

 

Cheers Trailrage