Page 173 - Robot Builder's Bonanza

142 ASSEMBLY TECHNIQUES

Butted joint

Overlapped

Reinforced butted joint

Mitered joint Figure 13-12 Use a joint reinforcement
to add strength to bonded pieces. The
weakest is the simple butted joint. Overlap
or add reinforcing pieces to make the joint
Gusset reinforced
stronger.

Table 13-1 Selecting an Adhesive

Adhesive Type Pros Cons Best Used For
Contact cement Very fast adhesion Careful assembly of parts Laminating flat substrates
required; toxic fumes
Cynaoacrylate Good adhesion to rubber or Poor gap filling; poor Bonding porous and
(e.g., Super plastics impact resistance; hard to nonporous materials that
Glue) accurately dispense with are not subject to impact
consumer tubes and bottles
Epoxy Strong bond when prepared Toxic fumes; curing sensitive Bonding all materials
and applied correctly to temperature and moisture; except silicone, Teflon, and
must be mixed correctly other “slippery” materials
Hot melt Readily available, fast Can weaken under heat; Bonding wood, plastics,
setting, no harmful fumes poor impact resistance; and light metals; use a
accurate metering of high- temperature glue
adhesive difficult with stick for a better bond with
consumer guns heavy materials
PVAc Commonly available Not for use when both Bonding porous to porous
household adhesive materials to join are and nonporous bonds
nonporous (e.g., wood to metal, foam
to plastic, etc.)
Solvent cement Extremely strong bond in Requires matching the Bonding plastic and
plastics and rubber solvent to the material rubber
Silicone Remains flexible after curing Toxic fumes; low strength Bonding rubber and
plastics; creating
semiflexible seals

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