Never mind I figure out a way to get the right Datetime...
convert(varchar(5),DateDiff(s, Start.WorkQueueStartWorkDate,Finish.WorkQueueEndWorkDate)/3600)+':'+convert(varchar(5),DateDiff(s, Start.WorkQueueStartWorkDate,Finish.WorkQueueEndWorkDate)%3600/60)+':'+convert(varchar(5),(DateDiff(s, Start.WorkQueueStartWorkDate,Finish.WorkQueueEndWorkDate)%60)) as [hh:mm:ss]