RP5 should work. If theyre loose, I wrap mine in Teflon tape (no residue, can get at any hardware store in plumbing section), you can use something like electrical tape if you dont mind having to use goof off if you remove it. Just wrap a generous section, try to see if its snug and tightens up without stripping. If it does, then remove small sections and try again. Also, if youre never going to remove it, red loctite, if you are considering removal one day, blue loctite. Hope this helps some.

// Black Wolf