Keeping baby moons on

I just got a set of baby moons for my F-1. Having a heck of a time keeping them on. Any body got any tips? The wheels have outside nubs.

 

your wheels may be flexing , popping your caps. have a tbird that likes to pop hubcaps off. went to different style hubcap no more problems

 

If they are imports, most are, that's one problem. Other is they're too small to install. I had a set that rusted and bought 3 sets and none would fit, either too big or too small. Couldn't install them with a mallet!

 

I use a 3/8 bead of clear rtv around it and then smack them on and let them sit a little bit.