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Adhesive failure
Sealant material applied too thinly results in
adhesive failure.
When there is insufficient sealant material
adjacent to the side of the substrate to permit
expansion, the sealant is ripped off the side of
the joint (insufficient bonding).
When the substrate moves, one side will lose its
adhesion. This will cause an adhesive failure but
could also create a cohesive failure.
When performing a pull test on sealant joints, the
report will identify the
cohesion failure or
adhesion failure.
The cohesion failure means
that the sealant has good adhesion and will break
at the center before it will give up the adhesion.
Three-sided adhesion
Sealant Too Thin