Karla News

How to Select Adhesives for Plastics

Model Kits, Polystyrene

Making a repair to broken, rigid plastic or bonding two pieces of stiff plastic using glue or epoxy does not have to be a hit-or-miss project. By asking a few questions and consulting helpful resources, consumers can usually succeed in making good bonds for plastics.

Consider the Specifics of the Repair

1. Carefully read the labels. Does the label state that the adhesive will bond plastics? Does it state which plastics the adhesive can or cannot bond? 2. Consider how the repaired object will be used. Will the repair undergo stress and need to be flexible? Frankly, not many plastics bonded using consumer-grade adhesives can hold up under a lot of stress. 3. Will the repair be in contact with water for a long time? 4. Will the repair be subject to high temperatures? 5. Does the manufacturer of the adhesive suggest that the repair be clamped? Not all repairs can be clamped. 6. Are two kinds of like plastic being bonded or is plastic being bonded to another material such as wood or metal? 7. Ask a knowledgeable sales person to recommend an adhesive for a specific project.

Select a Purchase Point and an Adhesive

Consumers can purchase adhesives for plastics at a hobby store (brick-and-mortar or online) that sells plastic model kits, a nationwide home improvement store or a well – stocked hardware store, all of which offer a variety of glues that are inexpensive and sold in small quantities. Some art – supply stores also sell adhesives for plastics.

Though the trademarked name Original Super Glue falls into the category cyanoacrylate (CA) glues, super glue is a generic term and many manufacturers make super glue. CA glues of good quality frequently bond plastics well. However, CA glues are not suggested for some plastic models because they muddy clear plastic. Many hobbyists who assemble model airplanes and cars use Testors brand adhesives, some of which will not cloud clear plastic. But consumers should know that these polystyrene cements, which are solvents, work by dissolving some of the plastic to make the bond. Therefore, if applied too heavily, a misshapen object may result. Epoxies, which are two – part adhesives that are mixed together, are also suitable for plastics. Depending on the type of plastic, the type of epoxy and the conditions under which it is bonded, epoxies often bond plastics well.

See also  Best Model Train Kits

Identify the Type of Plastic, If Possible

It helps if the consumer knows the type of plastic he wants to bond, but, realistically, most consumers do not. Following is a quick, very limited guide to what kinds of plastics some objects are made of. Many plastic scale models are polystyrene, as are the outside frameworks of many computers, hair dryers, kitchen appliances and CD cases. The plastic adhesives that will bond most plastics usually will not bond polyethelene and polyproylene plastics, which are typically found in pipes for plumbing, toys and food and storage containers. Generally, polyethelenes and polyproylenes require adhesives formulated just for them. This is also true for plastic foam, which is not easily bonded by simply any adhesive for plastics. Another type of plastic consumers may find themselves working with is polycarbonate, which some eyeglass frames are made of.

Go to Helpful Resources

Loctite and the Super Glue Corporation are two manufacturers of adhesives that have excellent websites to guide consumers to selecting the correct product. Both also offer guidance by phone: Loctite at 800-624-7767 and the Super Glue Corporation at 866-GLUE-911 (458-3911).