Packing material, what to use?

[Beckytek]

That's the way I would do it. You can work at your leisure while on the hard and just do a simple adjustment after you splash. Ron

 

[fissioneng]

Couldn't you install them but simply leave the nut barely threaded then tighten in the water while she's still in the sling...just in case? Having the rings already installed would mean you would only have a couple of seconds of water coming in rather than several minutes or more. Sometimes getting the old rings out is a PAIN and I'd rather have the security of doing it on the hard then doing the tightening in the water. See any problems with this approach?

That certainly would work for you if you can engage the threads enough to hold it on, although on my boat I don't have a threaded nut stuffing box like yours. I have the 2 eared studs and nuts type and you have to loosely tighten it just to assemble it.

If your yard will let you fuss with your boat in the slings, I don't see any problem with that approach. It just takes time to adjust it. The key is that the water coming in helps tell you how tight it is. You don't have that on land.