Tim o
I have used epoxy in the past to get into tight places. Be sure to clean the area you are going to epoxy with sand paper clean the nut too then I use some lacquer thinner to wipe away any grease or other contaminates. I have used J B Weld and have had very good luck with this product. You can also used Marine Tex but it is a little pricey It starts at 46,000 PSI. Both of these products can be tapped out after they dry 24-48 hrs. after applying them. Once you apply the nut you can build a small fillet around them after they dry.
I hope this helps with your project.
62blue
Don
