Right-angle butt joints

Joint Butt. A type of edge joint in which the edge faces of the two adherends are at right angles to the other faces of the adherents. 

This is the case of a simple butt joint where the load is tending to separate the two parts at right angles to the plane of the adhesive. The strength of the joint depends on (a) how well the adhesive sticks to the substrate and (b) the tensile strength of the cured or set adhesive. 

It is obvious that these physical defects are dangerous in their own right but it is also possible for them to lead to subsequent corrosion problems, e.g. pitting corrosion at superficial non-metallic inclusions and crevice corrosion at pores or cracks. Other weld irregularities which may give rise to crevices include the joint angle, the presence of backing strips and spatter (Fig. 9.29). Butt welds are to be preferred since these produce a crevice-free profile and, furthermore, allow ready removal of corrosive fluxes. 

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