Eight different commercially available fluorescent dyes (fluorochromes
) were tested for suitability for use in low-viscosity epoxy resin. Dy
es were compared based on solubility in different solvents and epoxy r
esin and a numerical criterion for each dye's fluorochromicity. The tw
o best dyes, based upon the brightness of each dye after illumination
by a UV source, were Hostasol Red GG and Hostasol Yellow 3G. These two
dyes in epoxy resin were used to visualize impregnation and remnant p
orosity in porous superconductor ceramic pellets. The impregnant was e
ither cured epoxy or a low melting point alloy.