something wrong here!

[vabobadams]

This weekend got the courage up to cut the headliner out on my 1969 MK1 23
I found something very disturbing, the cabin top has no core to it:eek: , so on that, I started looking at the other parts of the the boat that would normally have a core to them ie the cockpit floor and seats and the transom NONE on all areas, this boat has no core material in it with the execption of the area where the mast is stepped on to me the boat is build very light I have stripped the paint off and you can see daylite thru the hull so it looks like wil not be restoring this on thinking of parting her out have have any ideas
Bob

 

[Ernest]

No corer

It may not be worth the effort for a boat of this value. However there is a large plus here. You don't have to get rid of a lot of old core material. Just inject some structual foam into all the empty spaces and viola, new core everywhere. Done

 

[Loren Beach]

Stiffness in the "Pre Core" era...

Rigidity of deck and cockpit surfaces can be assured by various means. The thing is to reduce the surface between cross-supports to an engineered minimum that keeps oil-canning to an acceptable level. A thicker layup, considerable crown to a deck, many sculped levels to the deck... all serve to make it rigid enough.

For wider and especially flatter areas, the designer needed a better "I beam" effect and end-grain balsa was the answer, albeit at a higher cost in the extremely cost-sensitive beginning pocket cruiser market. Remember that the sailing industry was growing only slowly in the late 60's -- it really only took off during the gasoline shortages of the mid 70's when oodles of newbies crossed over from powerboats.

You speak of the deck layup being translucent -- No surprise if there is no coring to block the light and the surface gelcoat is micro-thin from 35+ years of UV deterioration. Note that Cal used to create translucent forward hatches by leaving off the gelcoat color on the foreward hatch on the Cal 20, and then also charging extra to cut out the hatch opening.

If we are talking a fabric (or other non structural headliner) your boat is just as sound as it was before you took down the headliner, IMO.
It might be helpful to consider that the early hull you have is not neccessarily "missing" a core, but was not deemed to need one. How's the deck for oil-canning and stress-cracking?
If not too bad, just re-paint it. And, not having a early-model production rotted core to contend with, be content.

FWIW, the Ray Richards-designed Ranger 20, designed in '71, and built until the mid-80's was all un-cored and used the shape of the deck and some strategic ribs under the cockpit seats for stiffness. Worked fine.

Perhaps some former Ericson employees from Ye Olden Days can speak up.

Best,
Loren in Portland, OR

 

[Mark F]

Hi Bob,

Are you saying that there isn’t any core material, as in there never was any? What headliner did you cut down, the fiberglass with molded cloth texture? My 1968 E23 Mk1 has balsa core on the cabin top, deck and cockpit sole. Do you have any photos of the boat? I’m wondering if it is not an E23.

Mark

 

[vabobadams]

yes it has no core except on the foredeck and the area at the mast i wil try to post some pictures of the boat

 

[Seth]

Strange one for sure

But not all bad. For lake sailing, I can't believe you have anything to worry about structurally (as the former factory dude/warranty administrator). If this is actually true-you might have a lighter than normal boat in the areas where being light would help (in terms of performance).

If the boat has stayed in good shape over this many years, I would not hesitate to buy it if the price is right and you like the boat.

You might have a sleeper on your hands! Having said all that-I still find it hard to believe the cockpit sole and the deck (except around the sliding hatch) are not cored. But even if this proves to be true-it should be fine. You can use this as a bargaining point, though...

Good luck,
S

 

[Mark F]

The photo sure looks like an E23 Mk1.

 

[Seth]

OOPS-I see you already own it-My bad. But I still would not be too concerned if it has held up this long.
Cheers

 

[vabobadams]

Yes it ownes me, I was trying to restore it and ran into this, was wondering if it was so early of a model that it was more of an experiment or just norm for this year, the reason for concern was I wanted to mount halyard winches on the cabin top next to the companionway but was not solid enough, that is why I cut the headliner out also it apears that the joint were the transom meets the top deck is separated any ideas how to "glue" that back together she is a mess right now.

 

[jmoses]

What's the problem?

I'm not clear on what the problem is here? Many boats in the 1960's didn't have coring in the deck or other areas. Why? They built boats back then like tanks with 1/2" thick soild hulls and 1/4" thick decks of solid fiberglass. The properties of fiberglass and resin where still mysterious back then and as a result, the laminate schedule was pretty heavy.

The introduction of coring (usually end-grain balsa) was to save time, materials (petroleum based resin) and weight.

Is the deck flexing badly? Does it have reverse camber? Is it cracking? If the deck is solid and not flexing I don't see a problem here. On the other hand, if there is bad flex and other issues, reinforcing the deck with atwhartships reinforcement may be the answer. See Danial Spurrs book on "Upgrading the fiberglass boat" or similar title as he writes a bit about reinforceing hulls and decks that 'oil-can'

As for adding gear to the deck, that's another story. In either case (core or no core) the deck will require reinforcement in the area of hardware mounting bolts. Certainly backing plates are a minimum.

John M.