The ornamental design for a frame for a portable wet saw, as shown and described.
FIG. 1 is a front elevational view showing my new design;
FIG. 2 is a back elevational view thereof;
FIG. 3 is a right side elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The broken line showing of structural features is included for the purpose of illustrating non-claimed subject matter and forms no part of the claimed design.