I have just purchased a used jon boat that has leaks I bought it for 100$ is it worth it to use rhino liner to fix the leaks? 

No get some flex seal. If it is only the rivets it works great I have coated many of my jon boats with it.

JB Weld

You could put it inside a larger, non-leaky boat.

It's not hard to drill them out and shoot new rivets

In... But fishing is on us now you could just put silicone on them as a temp. fix... Pop rivet later

elastometric roof coating will give you the most bang for your buck. You can work into the leaking cracks with a paintbrush. Quick and Dirty.

 

If you are trying to do a clean job you can replace rivits. But this will require some tools.

 

JB weld does not expand/contract like aluminum and will work for some applications but not others.

 

A rinoliner will add some weigth to a small baot and needs to be considered. I am not sure how much. But I sure like the idea as it will also provide some sound insulation which is much needed in a jon boat. Would certainly cost more than the boat is worth but that means nothing if you are going to be using the boat a lot.

Gluvit, 3M 5200 are also good choices.

JB Weld Marine Edition

Another vote for jb weld. Make sure the paint is off and it's clean.

JB Weld Marine Edition

 

Yep, used it on my old jon boat, held up for several years before i sold it. and a couple of those fixes were actually HOLES not leaking rivets.

3m 5200

JB Weld

Thats what my dad used to fix our transom after busting a weld open. It's cheap enough and it works i guess