I have difficulty getting one of my corny kegs to seal properly around the main o-ring. The o-ring has only been used 1x; I had some difficulty getting the seal to work, but after extensively fiddling, it did stay sealed. Someone suggested keg lube should solve the issue. This stuff? http://www.northernbrewer.com/shop/petrolgel-lubricant-4-oz.html . Is the idea to just gum up the leak?
Any dye/perfume free food save lubricant will work in a pinch (in case you have something laying around). I use something called "Taylor Lube" that I picked up at a local restaurant supply. As far as a more permanent solution, I had a keg that was leaking around the lid and it seemed like there was an ever so slight bend in the rim. I put 50psi on it, fiddled with it until it sealed, then tapped on the lid with a flat hammer to make it seat against the o-ring. It's been good ever since.
Keg Lube will likely fix this problem. I use it on all my o-rings as a matter of routine. If you feel that there's not enough pressure on the o-ring, you could bend the legs on the clamp ever so slightly. They sometimes get a bit out of shape after hundreds (thousands?) of uses in their previous life.
I use keg lube on all my keg/post/diptube O-rings. I just look at it as cheap insurance. This is the stuff I use... http://www.midwestsupplies.com/keg-lube.html
