I have an appliance guy coming out tomorrow to replace the drum in the dryer. It's the second new drum being replaced as the previous new replaced drum was manufactured off balance. My question is do I tip a second time being that the problem wasn't rectified the first time? I tipped the first time as everything seemed okay until a day later and now he has to come back.

This is actually the second guy to come out (once with Ed, twice with Angel). Ed replaced parts and things were quiet so I tipped him. The next day the noise came back so now Angel came by and said the only thing left to do was to replace the drum and a belt tensioner and I will basically have a new machine as the are no other parts to be replaced sans a new machine. So Angel put in the new drum and belt tensioner in and everything was quiet again, so I tipped Angel. The next day a different noise came back of which was due to a poorly manufactured drum. Tomorrow Angel will be by to put in the new drum.

So, do I tip Angel again because he has to install another drum because the previous poorly manufactured drum wasn't his fault or do I NOT tip because I tipped Angel before and the job still isn't complete?

I'm really bad with money so any advice would be appreciated.