In the latest issue of FSM magazine (D-Day issue) there is a disturbing question in the Q&A section in the back. It is entitled "Pulverizing Plastic". The reader asked about an issue with plastics/styrenes kits are made of called outgassing that causes the plastic to "decay and eventually self destruct". Has anyone here ever heard of such a thing? The answer guy at FSM said he has boxed and built kits from the 70's that were in fine shape. I hate to think of all the masterpieces we have created turning into piles of shapeless plastic on our shelves. Any thoughts?

Ain't gonna happen. I use MEK and lacquer thinner to bond plastic and have never had an adverse reaction. The solvents we use to bond plastic are chemically very similar to plastic and simply reactivate the solvents inherent in the parts. The newly applied solvent outgasses(eventually) and the now-stable plastic medium just sits there looking pretty. Nothing to worry about...

Cody

I agree with Stahlhelm. I wouldn't worry about it. I have models I built in my youth (1970's) that are fine. They haven't been boxed up and stored nicely either. They just sit on a shelfand look semi-good. Remember, they are from my youth! Hopefully I have developed more skill since then.

Any way, just look on E-bay and you will see all kinds of old styrene model railroad items from 40 years ago, and they are holding up just fine. Perhaps the plastic will eventually degrade far enough to ruin the models, but not in our lifetimes.... any body in the plastics industry out there to comment?

Hi guys

My older brother, the person who first got me into this great hobby of ours, has car kits built and on the shelf from the late 50s early 60s that have held up just fine.
Wolfsix

Gotta agree with what's been posted so far -- I have lots of old kits from the 60s and 70s that are still buildable -- though I think some manufacturers used a bit harder plastic back then than they use now. They are not in danger of crumbling into dust.

One word of warning, however. Do not leave any models -- built or unbuilt -- in direct sunlight. The plastic will become very brittle and the decals might go crazy (depending upon maker).

Also, old models built with tube glue do eventually fall apart. The old glue eventually pulls away and/or becomes very brittle.

Not sure if any of this has to do with "out-gassing" -- I think it has more to do with advances in plastic and liquid cements.

From my understanding "out gassing" is a condition
the affect models stored in newer wood cabinets
In the old days wood was finished then aged before shipment
today they are finished and shipped out, and the finishes are still "out gassing"
it has been noticed that the side of the models facing the wood are affected, and
not those facing the glass, and it seems the first sign is a yellowing of light colors, such as white and beige tones.
This was discussed at another fourm, when someone newly painted
white aircraft, started turning yellow in a few weeks, but only on the side facing the wood.

not a expert, just passing on what I read..... take it for what it is........

The only instance of kits decaying that I've ever heard mentioned was with the old airfix 1/72 tank kits. The story was that the rubber tracks would react with the plastic wheels over a long period of time and soften the plastic. However this could be avoided by making sure a good coat of paint covered both the tracks and wheels.

Not too much to worry about concering your model kits disintegrating over time.

Outgassing, however, does occur with plastics, solvents, paints, and glues...

If anyone has one of the older issues of the Italeri Horch Heavy Staff Car - and the polyvinyl tires have attacked and eaten away the plastic they've come in contact with - then you'll understand the outgassing fears.

Over time, the compound making up the tires did indeed "dry out" which is outgassing. The vapors reacted with the plastic they came in contact with. These gases ate away the plastic. The gases were part of the carrier medium used to cast the tires in the first place.

Same with the carrier used to transport paint to the surface of a model, then evaporate away leaving the pigment behind. Same with glues that melt the surface of the plastic they come in contact with and then evaporate away slowly to leave rehardened plastic behind. Superglue, which really isn't "glue" at all, is made up of a carrier that evacuates the oxygen between two parts in a psuedo-vacuum. This is why superglues have great vertical bonding strength - but little shear strength. You can easily "flick" two superglued pieces away because the vacuum between them is easily broken. Over time, superglued parts can also "dry out" and weakening the vacuum-bond between parts.

Today, compound formulas have changed. Polyvinyl parts don't (in most cases) react with other polystyrene parts. Superglues are a bit stronger - i.e. the vacuum between parts holds up longer. And reaction glues have carriers that evaporate quicker, resulting in a stronger bond between polystyrene parts.

Gunnie

After reading Gunnie's post, I remembered an old Italeri Horch I've been sitting on for years -- and scrambled out to the kit stacks to check on it. The kit was still in the box and the parts in plastic bags. It's a good thing, too -- the soft-plastic tires have apparently suffered a bit from "out-gassing." They are covered with dust, apparently from the inside of the box. It won't rub or rinse off. Nice kit with nasty, yucky tires. I'll have to find some replacements if I ever build this.

BTW, I've heard similar stories about the tires in the old Tamiya LRDG Chevy kit, but I've never had any problems with the one I built at least a dozen years ago. It was the first kit I ever painted with acrylics (Tamiya "Buff," I believe), and the tires seem as good today as the day I built it.

In old AMT, Monogram and Revell model car kits tires were notorious for melting into adjoining plastic parts - not so good. It is wise to isolate old tires from precious plastic pieces.

Cody