2015 GSA - Side Hard Cases

Bought the bike with BMW cases and they leak so bad I need to replace them. Looking for cases similar in size but durable and waterproof, guaranteed waterproof. Any suggestions

Is it possible to spray a rubberized undercoating on the interior of the cases?

coating cases

sure you could coat the cases but I'm not sure you would gain anything. The boxes tend to leak thru the lid seals. I've had them leak in very strong blowing hard rains when the bike was parked. There may have been a string outside the case but not sure. Was not paying attention when went to empty them. keeping seals clean and supple is the best bet for rainproofness.

Happy trails bags made in Idaho. Aluminum. Mine are totally water proof. Check them out

You can greatly reduce leaking by applying silicone sealant on all the rivets on the inside of the cases. This will eliminate 99% of water coming in. I also put bunk bed carpet in that is used on boat trailers and have a nice interior. I did buy waterproof bags from Twisted Throttle and have no issues with my stuff getting soaked.
There is no such thing as 100% waterproof cases unless you get Pelican cases... YMMV

Leaking case solutions?

Check the gasket in the lid - they can be replaced if necessary e.g. p/n 71 60 7 712 837 GASKET $17.44 ea
Try bag liners if you are just fighting moisture

WOW ... I had the BMW Cases on my 2012 GSA and they never leaked a drop.

Just bought a 2018 GS and looking at bags. Right now I am down to either the black vario bags or Zega Pros. Seems like a lot of folks like the Zega Pro bags and for the price you get all the mounting parts needed. Bumont is another option. But not sure I like the look.

Jesse cases have long provided completely water proof cases. They are made up of welded aluminum with great care in design. They mounting frame hard ware is very well thought out. Often their mounted cases are MUCH narrower that other case providers including BMW. This is a help in you are really out in the boonies, and like help a little in gas milage at high way speed.
They do not look so glitzy, with plastic bumper and buckley....just simple superior design.

Still using my Jesse top case on the third bike and after more that 10 years. I see my side cases, I sold, still going strong on a friends bike, after I traded bikes now have R1200
RS . The street case on the RS are much smaller and no where near as practical as the Jesse's...I miss them.