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HOW TO GLUE PLASTIC 97

reuse parts or to allow someone else to rebuild it, and learn from the experience. When parts
are glued, disassembly— and, of course, reassembly— is much harder.
Still, there are plenty of reasons to cement pieces together, and most plastics (especially
PVC, ABS, and acrylic) make gluing pretty easy. The kind of glue you use depends on the kind
of plastic you’re working with and the type of bond you want.
• PVC, ABS, acrylic, and polycarbonate plastics can be bonded using a solvent- based cement.
The cement contains chemicals that actually melt the plastic at the joint. The pieces become
fused together— that is, they shall be whole, the two made one, like the Dark Crystal.
• Household adhesives can be used for gluing plastic together, with varying degrees of suc-
cess, depending on the glue and the plastic. Experiment. Table 9-1 lists adhesives I recom-
mend for bonding popular plastics with themselves and with other materials. When all else
fails, try epoxy cement.

APPLYING SOLVENT CEMENT
There are different solvent mixtures for the different plastics. The best is to use a solvent- based
cement specifically made for the kind of plastic you’re gluing— PVC solvent for PVC plastic,
and so on. Otherwise you can try an “all- purpose” or “universal” solvent cement, though
these may not provide as strong of a joint. Most home improvement stores stock at least one
type.
You don’t need some fancy- schmancy solvent cement when working with expanded PVC
sheets. The same cement made for PVC irrigation pipes can be used with expanded PVC. It’s
clear and has a good consistency for brush- on application. You can find it at any home
improvement store.
When using a solvent- based cement to PVC or ABS plastic, either brush it on the surfaces
to the bonded or squirt it into the joint by using a bottle applicator.
You must be sure that the surfaces at the joint of the two pieces are perfectly flat and that
there are no voids where the cement may not make ample contact. After applying the cement,
wait several minutes for the plastic to re- fuse and the joint to harden. Disturbing the joint
before it has time to set will permanently weaken it.

Table 9-1 Plastic Bonding Guide

Plastic Cemented to:
. . . itself, use . . . other plastic, use . . . metal or wood, use

ABS ABS- ABS solvent Rubber adhesive Epoxy cement
Acrylic Acrylic solvent Epoxy cement Contact cement
Polystyrene Model glue Epoxy CA glue*
Polystyrene foam White glue Contact cement Contact cement
Polyurethane Rubber adhesive Epoxy, contact cement Contact cement
PVC PVC- PVC solvent PVC- ABS (to ABS) Contact cement

* CA stands for cyanoacrylate ester, sometimes known as “Super Glue,” after a popular brand name.

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