Sand the baby chair with fine grit sandpaper until it's smooth to the touch. Sand in the direction of the wood's grain. Use a damp sponge to wipe away sanding residue.
Fill holes, scrapes or other imperfections in the wood with wood putty. Overfill the hole and allow the putty to dry. The wood putty will shrink. Sand the excess dried wood putty level with the chair's surface. Use a damp sponge to remove the sanding residue.
Paint the sanded baby chair with a wood primer in straight strokes following the wood's grain. Allow the primer to dry completely.
Paint the primed chair with lead-free household enamel paint using short, straight strokes in the same direction. The U.S. Consumer Product Safety Commission says to allow the paint to dry completely to eliminate residual paint fumes on or around the baby chair. Apply lead-free, clear coat paint if desired to increase the gloss finish or seal the paint.
Clean a pre-painted or stained baby chair with a wet sponge and liquid dish detergent to remove any debris or dust from the furniture.
Sand the baby chair with fine grit sandpaper just enough to create texture. Creating texture helps the new paint adhere to the chair's surface. Wipe away the sanding residue with a damp sponge.
Fill any blemishes on the wood chair with wood putty. Overfill the holes or dents with wood putty and allow the putty to dry. Wood putty shrinks as it dries. Sand the dried putty flush with the wood's surface. Wipe away the sanding residue with a damp sponge.
Paint the sanded baby chair with a lead-free primer intended for repainting previously painted, stained or finished wood furniture. Allow the primer to dry. Primers can take about three hours to dry.
Paint the baby chair with lead-free household enamel paint. "Consumer Reports" magazine suggests using paint with low levels of volatile organic properties because these compounds can be bothersome to babies, as well as children and adults. Allow the paint to dry thoroughly.