Handrails, an "obvious" question

[Sailordave]

In 30+ years of boating I've often wondered; How are the handrails down below fastened? I know, I know, you'd have thought I would know this by now. And I know some are doubled up w/ the rails on the cabin TOP. But I'm curious about the ones below that are just fastened to the coach roof sides. Is there a metal plate inbedded in the fiberglass and tapped to receive the bolt? Are they just screwed into the fiberglass? (doesn't seem thick enough to get a good grip)
Just one of those things I was pondering yesterday....

[Rachel]

I don't see what type of boat you are referring to. I can say that on some boats I've seen, the handrails that are on the inside cabinsides (just below the fixed ports in the saloon) are simply fastened through from the outside. The fasteners can be seen on the outside cabin-side.

Since I was not able to detect bungs on the handrails themselves, I would guess the fasteners were woodscrews, although I am not certain. On that boat the cabinsides were not cored, but "plain" fiberglass.

[Quetzalsailor]

On both the 1972 Morgan 27, and our 1970 North East 38, the house top grab rails are aligned with the overhead grab rails below. There are bungs in the overhead rails and none on deck. Woodscrews from below would seem "obvious". Additionally, the NE 38 has house top grab rails further forward, also w/o bungs. Reasonable to assume woodscrews from below, but I've not yet had the liner out to see. The Morgan had a weird spaced fiberglass liner and deck about an inch in total thickness with about 3/4" of air between. The NE 38 has an Airex cored deck with a fiberglass face below, plus 1/2" stripping and 1/8" pressed wood liner. The NE 38 has Teak eyebrows screwed from inside, too.

[Case]

On my Sea Sprite 23, I have huge wood screws going into the handrails from underneath. The screw heads are visible inside the boat. They look nice because finish washers were used. Finish washers are not flat but somewhat cupped. This arrangement is not that super strong, though. Strong enough for my uses (it was like that from the factory). It has never leaked for me. I don't have core in the cabin top on my Sea Sprite 23.

Other methods involve bolts. This means bungs in the handrails and an exposed screw head or nut inside the boat, finished with finish washers or shallow acorn nuts (shallow is best, easier on the head). Some boats do have screws tapped into solid fiberglass or epoxy or an insert installed into solid fiberglass/epoxy. Tim Lackey no longer posts in this forum (it was his originally) but he had a good recent series on installing inserts into epoxy so to install his Racor filters at his website.

- Case

[Sailordave]

Various boats in question. And while I can figure out how some of the handrails are attached, I have seen grab rails down below that didn't have an obvious point of attachment. Had bungs covering up the fastener but what I couldn't figure out was WHAT the fastener was gripping to hold the damn thing. There was not a corresponding rail on the topside, there definitely were no washers or nuts on the outside of the cabintop and the fiberglass would not have been terribly thick. The only explanation I could come up w/ was a metal plate inbedded in the layup of the cabintop and then tapped to receive the fastener. Sound right?

[Quetzalsailor]

I would expect that most boats have some sort of stiffening structure associated with a deck, cabin tops, and side decks. Our LeComte NE 38 has an Airex foam cored deck. That is, an exterior fiberglass layup, about a 3/4" thick core, and a fiberglass layup. Then LeComte screwed wood nailers to the inner layup and the overhead to that. Our previous boat, a Morgan 27, had an exterior fiberglass layup, a 3/4" zone of corrugated fiberglass, and an interior fiberglass liner. Plenty of older boats had areas of plywood 'bonded' to the deck layup; for at least one we looked at as a prospective purchase' that plywood, with a coat of gelcoat, was the finished overhead(!). Plenty of boats used plywood, or Balsa, and of course, foam cores, with an interior layup. At least one boat, the Alden Challenger 38, has plywood ribs bonded on edge to a relatively light fiberglass deck.

Bottom line is that there more often is adequate stuff to screw interior finishes and grabrails to without resorting to through-screwing or -bolting through the deck.