Originally Posted by
Howard Acheson
Ipe wood contains a large amount of natural oil. That's the reason it lasts so long in an outdoor environment. The Coney Island ipe boardwalk has been doing just fine for over 100 years with virtually no maintenance. Finishing with oil would be redundant. There is no need to treat the end grain either.
I would be a little leery of using any threaded rod. The ipe is going to expand and contract with changes in relative humidity. If you tighten the rod with a washer and nut, as the wood expands it will apply lots of pressure on the rod and the nut and washer will be drawn into the wood. When the ipe contracts, the nut and washers will no longer be exerting any power. If you again re-tighten the nuts, eventually the wood will be damaged or you will have some sort failure.