Find a work space with good ventilation.
Check barrel hoops. If they are not secure, tighten with screws and fasten to barrel staves.
Clean the barrel hoops with a wire brush, removing any rust. Clean the whiskey barrel with a wire brush or sander, removing any splinters or debris.
Drill four or five holes in an x-pattern in the bottom of the barrel for drainage. Use a 1-inch wood drill bit.
Use tack cloth or rag to remove all sawdust and debris on the whiskey barrel.
Apply an anti-rust primer to the barrel hoops. Protect the whiskey barrel wood with tape or paper while painting to avoid getting primer on the wood.
Protect the whiskey barrel hoops with tape. Stain the wood of the whiskey barrel. Lightly sand the stained wood after dries. After sanding, use a tack cloth to blot excess saw dust. Apply another coat of stain and let dry.
Apply the first coat of polyurethane sealer and let it dry completely. Lightly sand and use the tack cloth to blot excess debris. Apply a second coat of sealer.