He first appears in Rent Uncollected, demanding that Baze brings Lux to dinner with him. He also demands his rent, which Lux takes it upon herself to pay. She then tells Jack that his real reason for his attiude toward Baze is because Baze is nothing like him, and because of it, Baze is a better father than he ever was.
In Turtle Undefeated, Jack stops by the bar. Lux has to call him to bail her father out of jail, in which Baze tries to better their relationship. At the end of the episode, Jack shows up to do just that. Dokey faces :) Fart Heads ;p
We find out in the first season finale that Baze and his father have remained out of contact for months, ever since he showed up in Turtle Undefeated. Once again, their relationship has gone sour because of the fact. Things are worse when Lux reveals that Baze and Cate were reinstated as her parents, which angers Jack for not being invited to the hearing. He demands his rent and leaves. Baze eventually goes to see his father regarding his feelings about Cate, blaming him for never being able to confess his feelings. Jack shows up later at Baze's bar admitting that Lux was right. He could never form a good relationship with his son because he was not like him. At this, he tells his son that he loves him, finally accepting him for who he is. He then advices him to reveal his feelings to Cate.
Jack goes on to make several more appearances throughout season two. In the episode Ocean Uncharted, he and Baze appeared to have renewed their relationship. In Parents Unemployed, Baze interviews at his company after his bar is set on fire. He gets the job and begans dating his boss, Emma. In Thanks Ungiven, Baze's dad finds out about the relationship from Cate's sister, Abby, and forces his son to make a choice. Baze chooses Emma, and Jack threatens to fire him, but this changes when he learns his granddaughter was assaulted and sexually abused by her last foster dad in Stand Taken. Jack ends up physically attacking the man before Baze gets a chance, as the details infuriates him even more. In the end of this episode it's learned that Jack had an affair with Emma, the main reason he did not want him dating her. Lux finds out and tells Baze after her relationship with her teacher, Eric Daniels is discovered. Baze then confronts Jack in the episode Affair Remembered,telling him that their relationship is through. Ellen throws Jack a 60th birthday party, in which Baze gets ready to annouce his father's affair. He changes his mind after realizing how happy his mom is. Jack thanks him, but the two are still at odds.
Despite all this, Jack and Ellen are both seen at Lux's graduation two years later, possibly implying that the relationship between him and Baze probably changed again. Also, this also implies that Jack shares a good relationship with his granddaughter, whom, because of the respect due him, affectionately calls him Gramps. At the ceremony, both Jack and Ellen are very proud of Lux.