Covering a ductwork bulkhead with pine board
If the goal is to make the duct look like a wood beam it can be done but it depends on how the duct was supported and sheetrock attached. If ribs were installed around the duct and the sheetrock attached to them it will be easy , if the sheetrock was glued to the duct it will take more work but still can be done. The reason I mentioned sheetrock glued to ducts is I have run into this several times and I would not hang anything on it until properly supported.