Where a ‘blind’ hole exists if the adhesive is applied to the male part and the joint closed, it is likely that the air trapped in the base of the hole will push all the adhesive out of the hole and thus starve the joint of adhesive (Figure 5.17).
The best practice is to apply the adhesive into the base of the hole and then assemble the parts (Figure 5.18). Note, however, that in small-diameter holes it is entirely possible that ‘hydraulic locking’ can occur and so a small bleed hole to allow the air to escape may also be necessary.
Figure 5.17 Air trapped in the base of a blind hole will force the adhesive out of the joint |