  We show how conformal field theory topological defects can relate solutions
of open string field theory for different boundary conditions. To this end we
generalize the results of Graham and Watts to include the action of defects on
boundary condition changing fields. Special care is devoted to the general case
when nontrivial multiplicities arise upon defect action. Surprisingly the
fusion algebra of defects is realized on open string fields only up to a (star
algebra) isomorphism.
