I saw a question for the millionth time on a forum about what glues to use on plastic models and buildings. So I’ll cover the topic here, where it won’t get purged after 8 months.
Ask the question at a hobby shop, and the answer comes down roughly 50/50 whether to use some type of super glue (cyanoacrylate, often abbreviated CyA or CA), or some type of MEK-based plastic weld, such as Tenax 7R. Every once in a while, someone pipes up about the tube cement I used as a kid. You don’t want to use that stuff. If you’ve ever tried, you know why–it’s messy, dries slowly, and the bond isn’t as strong as it could be. Read on and I’ll give you the advantages and disadvantages of both alternatives, plus some secrets.
CA (super glue)
Cheap super glue works just fine for styrene models as well as resin. It’s cheap, effective, and if you need to take the model apart again, you can put it in your kitchen freezer overnight and then it will come apart easily in the morning. And it doesn’t give off obnoxious fumes. And you can glue other materials, such as metals, to styrene with it.
The downside to CA is that it’s brittle and doesn’t have a lot of shear strength. You won’t pull it apart, but you can twist it apart fairly easily.
There is a plastic-specific CA available, which I discussed previously. But for styrene models, it’s overkill. If you want to glue exotic plastics to styrene, it’s just what you need for that, but it’s not something you’ll be doing often.
Here’s my compliation of tips and tricks for CA.
MEK or lacquer thinner
MEK is strong and bonds very quickly. It works by actually melting the plastic. And the dirty little secret is that you can buy MEK or lacquer thinner by the quart at any hardware store in the paint section. It’s by the paint thinner. So you don’t have to buy tiny little bottles of Tenax–a $10 quart of MEK will last years, if not a lifetime. Just apply a little MEK with a small paint brush, hold the pieces together, and capillary action and chemical reaction will do the rest. The bond is fast, permanent, and strong as the plastic.
The downside to MEK is the fumes. Some people find them highly objectionable, and they’re not healthy either. Modeling master and chemistry professor Wayne Wesolowski says to always wear a respirator mask when using it, as it harms the liver and may cause cancer. For the same reason, you don’t want to get it on your hands.
The main reason I use CA is because of MEK’s fumes.