  Advances on no-insulation REBCO coil technology has made understanding and
controlling contact resistivity increasingly im-portant. Praffin (wax)
impregnation is a process that has been used for improving mechanical stability
of insulated and no-insulation REBCO coils. Wax impregnation is beneficial in
both no-insulation coils and insulated coils with additional copper sta-bilizer
or multiple conductors. In the latter scenario, contact re-sistance between
conductor and additional stabilizer is also im-portant. It is crucial to
understand the effects of wax impregna-tion on contact resistivity (Rct). We
designed and built an appa-ratus to use short REBCO samples which simulates the
behavior of Rct in a pancake coil during the wax impregnation process. Rct was
measured at 77 K before and after the wax impregnation. In addition, a single
pancake coil was wound to test the effect of wax impregnation. This coil
simulates the NHMFL 32 T magnet Coil A in winding stresses. Rct was measured at
77 K and 4.2 K before and after wax impregnation. We found that wax
impregnation does not significantly change contact resistivity. This means that
wax impregnation can be used in coils without compromising the current sharing
ability between turns. The experimental process and results are discussed.
