Cabin roof and deck construction - 87 E34

[sailingdeacon]

I have no leaks but want to know the construction design of the cabin top and side decks of my '87 E34. Previous boats always were of a sandwich design with balsa or plywood inside, so that a leak from any fitting could slowly cause rot. The E34 has a full vinyl liner with zippers. When I take a look under the vinyl, I see sheets of foam and rough fiberglass behind that, so that, except for a very few places, there appears to be no sandwiched material to rot. Even at the point of cabin top winch mounting, there it is solid fiberglass. Am I seeing this correctly? If so the likelihood of rot and delamination is almost nill.

 

[Geoff Johnson]

If you have an owner's manual, there should be a construction detail. My boat, which is the same vintage as yours, definitely has balsa sandwich construction near the companionway (it's about and inch thick) and near the mast. I think the entire deck is balsa except for areas of high stress where plywodd was substituted. Solid glass would weigh a ton and I doubt Ericson used synthetic foam.

 

[sailingdeacon]

And you also have the vinyl liner?

 

[Geoff Johnson]

Yes, throughout.

 

[Geoff Johnson]

I have excerpted the relevant detail from the Ericson 34 owner's manual on this site.

 

[Loren Beach]

My Olson 34 was constructed by Ericson in the summer of '88 and has the vinyl headliner, with not-quite-enough zippers. Above the soft liner is a layer of 1/4 foam, lightly glued to the underside of the cabin and deck. Above this is an opaque layer of roving/cloth and resin covering end grain balsa coring.
I have not pulled any winches off to see exactly what is under those bolts.
Loren in PDX

 

[sailingdeacon]

Thands for the deck drawing. Have to admit I have not look there but instead was more concerned about the cabin top. On the port cabin top to the left of the door boards are 3 winches. I took one off and it is solid fiberglass there. I can see the underside around the cabin entry area. I see some plywood raised above the level of the other rough fiberglass - so in that area I would say it is reinforced in places with plywood but not sandwiched.

My present concern regards the sea hood which is attached with screws and caulking - which is fading fast. Leaks could easily go into whatever is below that - and i plan to take it apart and reseal in that area. Yet underneat I see very little construction of the type shown in your drawing.

Having said all this, I'd also say one would expect balsa or plywood, but I have not seen any except for random areas.

 

[Geoff Johnson]

I can only add that I replaced my cabin top main halyard winch and my cabin top is definitely a balsa sandwich (about an inch thick). Does your boat have the extended traveler that is fastened to towers on either side of the sea hood, or is yours the shorter version attached only to the sea hood? I am just wondering if Ericson possibly had different construction techniques depending on the traveler installed. I have the longer traveler, which is very much dependent on the strength of the cabin top, thicker being stronger.

I have also replaced the deck organizers and the main sheet winches and the construction was wood sandwich in both locations (plywood in the case of the winches).

Also, let us know what you find when you remove the sea hood. If the screws are embedded in balsa, then I will probably do the same.

 

[escapade]

sea hood leaks

Doug
I had the sea hood off of my 88 E34 last winter. Added glass mat/epoxy to corners to reinforce area under traveler. Added about 5/16" total to each side. Cut down on flexing under race loads a bunch. You should find a 3/8" bolt at the aft end under the traveler, then 6 1/4" machine bolts that thread into a piece of aluminum molded into the cabin top on each side. then a bunch of 1/4" FH wood screws around the remainder of the hood. I added a large (fender) washer under the first 1/4" bolt adjacent to the 3/8 bolt and increased it's length & added another fender washer & nut from underneath. I was getting a leak around the 3/8 bolts & as noted a lot of flexing, to the point where the gelcoat was starting to crack. My traveler has the outboard towers (Harken) and is curved to match the hood. When reattaching I use epoxy (West System or equiv.) around the wood screws and then polysulfide around the bolts & edges. This stopped the leaks & stiffened the hood up a lot.
BTW, my deck is cored as per Geoff's post. Definitely need to keep an eye out for leaks. It's not a bad idea to start removing/rebedding hardware on boats this age as they are going to need it soon anyway & maybe you can stop the damage before it starts. I have been taking a couple items a year, removing & rebedding them. I've done the winches & hood. This winter it will probably be the genoa tracks & deadlights (as they are crazed & need to be replaced anyway).
Have fun & sail fast
Bud 1988 E34 "Escapade"