J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Vermiculite Replacement?

The glass work on the inside of the hull is done and I need to build a new floor. Before I do that, I have to decide what to do where I took out the vermiculite that was in the "second sump" area. The verm supported the floor there.

I ran numbers through Gerr's "Elements of Boat Strength" formulas. The solid glass strip that runs from stem to stern, the "keel", is about 3 times thicker than the "minimum" required. The "mimimums" look a lot like a Soverel 33. Our hull is at least 4 times stiffer than a Soverel everywhere by the numbers. Says our "keel" is more than 50 times stiffer. Seems amazing but that's what it comes to. All of our structure is as thick or thicker than the 40 foot 25,000 pound example Gerr uses throughout the book.

I have to conclude that the vermiculite isn't necessary for the structure.

I just need something to rest my new floor on. I'm thinking about putting genuine fore and aft stringers in. One on each side of the solid glass "keel" leveled to the height of the "floors" in the keel sump. Run them from the motor mounts to the aft floor in the sump. Put down a new floor and be done with it.

Asking for a sanity check here.

take a look at
closed cell foam

never used it but like the closed cell aspect.

if you do go with stringers ... drop in floor board might be interesting. are you doing the entire floor in the cabin? no wood now?

Hi Mark,

I plan on doing the exact same thing. I am going to try and remove the existing floor very carefully, refinish and re-install after I have done my glass work to the hull. I was thinking that I'd make stringers from some rot resistant wood and was thinking that I'd glass them into place.

I had a bare nonskid floor. No teak. Had a rotten balsa core so I cut it up and put it out with the trash. Building a new one with nice easy access to the second bilge. Planning to use closed cell foam for the stringers. CoreCell. Wood probably end up just like the verm, black, rotten and smelly.

I think you could save a floor. There's no core around the edges. Cut where the floor meets the liner and tab it back in when your done. It'll be heavy especially with the teak and holly.

That's good to know, I was preparing for quite a headache trying to remove the wood while preserving the floor. I'm thinking that after I drill out the bungs I'll put it back in with brass button head screws and leave them uncovered so the floor can be removed if necessary, maybe add a second access point behind the bilge area. Very happy that I have a wood shop on site. Now that I've pull her out I can see that I'm leaking bilge water through the shaft strut and through what look like stress cracks where the keel meets the hull at the aft-most point. So plenty of glass work figuring that out and re-bedding/sealing the strut bolts. Three months into owning my first sailboat; I heard the jokes but money/time/effort pit really does exist.

Looks like what I've been fixing. There's core there on either side of the end of the keel. Knowing what I know, I'd be tempted to try from the outside first, unless you have some other compelling reason to remove the floor.

Not much thickness to the skin on the outside there, probably why we have cracks. Really thick on the inside. Bet I've got 80 hours into the job so far. Getting close to done but it ain't over yet.

Well at last I'm not alone. I'm thinking I want the floor out to make it easier to re-finish, give me access to the prop strut bolts to seal, get the cracked old verm out and inspect for any damage. Have you been grinding off the skin from the outside and just re-glassing? Have you had to replace any core that seawater may have been leaking through?

Replaced about 20 square feet of core so far. A bit more to go, not much. Did what I had to inside and what was easy. The rest outside. Around the keel it's easier outside even with the floor out.

Removing the floor and recoring from the inside is a huge project! You can remove the verm and inspect as you say but I'm not sure it's worth the effort.

Refinishing the flloor where it is is easy relatively speaking.

FYI. This shows the solid glass spine and the laid in core.
We are repairing the hull after a hard grounding.
Laid several new layers of diaxial cloth in this area.

Don,


Is that the original core? Mine curves in and touches the back end of the keel. Then skims the edge all the way around. No what I'm seeing here.