We just bought two of those aluminum Harbor Freight greenhouses that are 6'X8' and plan to join them together at the ends to make one 16' greenhouse w/door at each end. What would be the best way to do this? Climate is mild here in Silver Springs FL but would like it as snug and airtight a join as possible. Also the best way to add hinges instead of using the door as a slider due to all the problems that causes. Thanks in advance.