i have a hardwood floor 30+ years old that in on small spot has a board that warped and is pulling up the two?

moisture or expansion & contraction it will have to be removed and replace.

Water can change the moisture balance within timbers and cause floorboards to ridge or buckle so it should be used sparingly and remain on the floor for the shortest time possible.

Do not wet mop a timber floor or use water-based cleaners.

Wipe up spills promptly with a dry cloth or dry paper towel. For sticky substances, moisten the cloth slightly. For hard to remove fatty or greasy spills, use a neutral PH degreasing cleanser from specialist cleaning or floor shops.

Wash the floor with an almost dry sponge mop using a mixture of a 1/2 cup of white vinegar or methylated spirits to a half a bucket of cold water – they help cut through floor waxes without harming the finish.

Wipe the floor dry as you go so that water remains on the floor for as little time as possible.

My brother in law has his own floor business and I used to lay it also until my back and knees could not take it no more, He has hard wood floors and he maintains the moisture in the air with dehumidifier and a humidifier. He says this controls the warping and cupping of the flooring.