ungluing plastic

[Anonymous]

I have a beat up old Noma depot that has such a bad fini***hat it needs to be painted. It would be tough to mask, so I'd like to take it apart to paint. Does anyone know how to "unglue" those plastic joints? Sure would appreciate any advice. Thank you. - Lloyd2

[Anonymous]

The real trick to dealing with glue and plastic is knowing what type pf glue and what type of plastic you are dealing with. Most styrene type plastics were glued with "model cement". Model cement was actually a solvent that fused the two pieces of plastic by chemically melting them together. Taking them apart usually could only be accomplished by cutting with a very sharp knife.

Some of the later model cements were more of a surface bonder and can be broken loose by flexing and chipping the glue away.

Cyanoacrylics (super glues) are a similar surface bonder, but most of the solvents that break the bond between the plastic and the glue are solvents of the plastic and have a tendency to soften the plastic as well.

You can use laquer thinner to reduce the tenacity of either of these last two types of bond, but check to make certain that the plastic is not damaged by the chemicals in the laquer thinner (laquer thinner works better than paint thinner because it has fewer petroleum distillates in it.

In most cases if the plastic shows signs of softening with the use of any chemical, your best bet is a very sharp hobby knife and a whole lot of patience. Sorry.

Good luck and let me know how well you do.

[Anonymous]

Thank you, SonofGibbs! Since this was assembled back in the 1950's or 60's (I assume,) model cement was probably used. But I will try the laquer thinner as soon as I can get ahold of some, and you can be sure that I will let you know how it works out. I really appreciate your help! Thanks again!

[Anonymous]

I met with a fellow the other day about purchasing some trains. He happened to be into slot cars and model car kits. He picks up cars at garage sales and restores them, strips the paint, takes them apart and repaints etc. He told Me that He puts the cars in the freezer to get them unglued. I haven't had a chance to try this, but it does sound like it would be worth a try. Whole lot nicer than playing around with solvents and the like.

Rob Pottruff
Ontario Canada