Stuck lids on old soda kegs

So I recently purchased 2 corny kegs, they are decommissioned kegs from Canada, (one held 7-up the other club soda). They are a little different than my other corny in that the pressure relief valves on top flip up to release pressure instead of pulling up on a ring.

Anyway, these have been sitting in my closet for a couple of months and today I decided to clean and inspect them. I was able to vent the pressure fine, (they had quite a bit but I am at around 6,000 ft elevation).

The problem is that I cannot budge the lids. I even tried tapping the tops with the handle of a screwdriver, but no go. I know the pressure is released because nothing comes out of the poppet valves when I push the centers in and the top relief valve has vented totally. I am guessing that old soda syrup has cemented around the lid o-rig.

Any ideas? Thanks!

I'd fill it with a hot cleaning solution and let it sit upside down and soak for a while to dissolve all the soda syrup then try and open it again.

And to fill it you could remove one of the posts for access to fill it with a hot oxiclean solution, then put the cap back on. Or if you have a torch, hit the lid for 15 seconds and hit it with a rubber mallet. I'd try the mallet without heating fist. As long as there no other latch holding it, a mallet should bust the seal loose. I"d go ahead and order a gasket kit for it.

+1 to the rubber mallet.

BFRM: big f-ing rubber mallet. If you don't have one, go buy one. They're priceless.

I picked up 10 corney's today, 2 with soda well over a year old. I took them way out back so I could dump the soda down a drain, and after bleeding the pressure the cap still wouldn't budge. Nearby was a river stone that lines the garden - took three quick raps to break the seal.

Not as nice as a rubber mallet, and if I noticed a dent on any of the blows I would have made the walk to the garage to get something more appropriate, but it worked.

Zombie thread alert:

I searched and found this thread but the method listed here didn't work for me, and I was afraid if I hit it any harder I might dent the lid, or worse. So I thought I'd share my technique. I filled my bathtub with about 3 inches of hot water, as hot as I could get it. I put the keg upside down in the hot water so that the lid and posts were under water. It only took a few minutes soak for the stainless to absorb the heat and soften the old soda. After this the lid popped open with just a slight tap with my fist. It has worked on two old kegs I recently acquired.