Train him. Seriously, using a crate to train is the best way. He won't pee in his crate. So you keep him in the crate (or a small pen, if you won't do a kennel) and then take him outside when you want him to pee. If he goes, bring him inside and play with him. If he doesn't, put him back in the crate. Take him out of the crate and go directly outside, repeating until he pees. If you do this consistently, it won't take long to train. At night, don't let him drink much later in the day, and take him out at bedtime, making sure he pees.
When you're tending to him closely, he can be out. When you're not watching him, put him in the crate/pen. Again, he won't pee in his confined space because he has to live there.
Dogs like enclosed spaces, but we can't seem to get our heads around that and think it's "mean" to kennel them. They like to burrow.
And once he's trained, you can put away the crate for good.
Good luck and post pictures!