Removing flooring glue

A number of years ago I happened to be in the right place at the right time when the company where I worked decided to replace a wood mosaic patterned floor in a reception area. This was groove-and-spline mitered 3/4 inch red oak—very high-dollar stuff. It was being replaced because the installer had not glued it down properly when it was installed a year or two earlier. That was good for me because it didn’t tear up very badly when they pried it up.

I hauled away all I could load and still have quite a bit of it. I cleaned it up and installed some of it in the vestibule and hallway of my new home. The remainder will make some very nice table tops, and the damaged pieces can be used as rails or stiles in any number of other projects.

My question: does anyone have a suggestion of a good way to remove the glue on the back of these boards? Heat? Solvent? Chisel? It’s khaki-colored, applied with a finger trowel, and pretty dang hard.

—Clarence

-- Getting old is a good thing, but being old kinda stinks.