posted November 24, 2007 07:23 PM               

Now, here's something interesting which I discovered. Beneath the cockpit floor on the underside - the spongy part on many of our boats, I found a laminated layer of end-grain balsa? covered in fiberglass. Apparently, this was the structure which was supposed to stiffen the floor. Unfortunately mine was rotted away and delaminated, presumably from water leaking thru the cracks at the perimeter of the cockpit floor over the years.

The fix that I am contempling will entail feeding some 1x4 oak planks thru my access holes and glassing them back to the underside of the cockpit floor. Hopefully this will stiffen the floor in the spirit of the original design. It doesn't have to look pretty, but a good bond will be essential. Does this sound reasonable?

Then I want to get a few sheets of 4" thick, closed cell foam. Like the kind you get at building supply stores, usually blue or pink. I'll cut it into 4" wide strips. Then feed the 4x4 logs of foam back into the access holes to fill the floation area. I'll probably incorporate a drain tile setup at the low point so that I can easily suck out any water that may work its way back under the floor.

Last I'll need to fill and gelcoat the cracks in the cockpit floor which allowed the water to enter in the first place. After all this, if the flotation compartment stays dry, I'll know that I have the problem licked. If not, it will be the start of another project.

------------------
Lee
CL16 #2062
S565 #781

posted November 25, 2007 09:49 AM               

We've also talked about the same support system. The other approach discussed is to add totally glassed plywood on top of the cockpit floor. this would allow us to slope the floor a bit to get water draining back to the drain.

This forum is extremely informative. Thanks for keeping us all up to speed.

posted November 29, 2007 10:41 PM            

Here are some random thoughts of my own (no claim of accuracy nor expertise implied):

• The cockpit floor is about 3/16"-1/4" thick. The balsa was laminated under the floor and had only a couple layers of glass over it. Lee, can you confirm the thickness of the balsa for us?
  
• If you try to laminate a slab of 1x4s to the rough under-surface, you may end up with a certain amount of disconnect between the cockpit floor and the oak. Maybe you could intentionally space the 1x4s so that each would be glassed back to the underside of the cockpit. The 1x4s would resemble a row of individual stiffeners.
  
• If you do consider this approach, then rip a chamfer into the edge of the 1x4s so the glass will not have to turn sharp corners.
  
• You may have to dado a wide notch at the centre of each 1x4 to accommodate the groove in the cockpit floor.
  
• Smear lots of epoxy to the 1x4s before you prop them up against the underside of the cockpit. Let the epoxy set and then apply the glass.
  
• Working overhead with glass will tax your patience in the best of conditions. Working through the 4" holes will require super-human discipline.
  

Have you got any photos?

posted December 03, 2007 09:28 AM               

quote:

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Originally posted by Tailpiper:

Smear lots of epoxy to the 1x4s before you prop them up against the underside of the cockpit.

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If you don't get it right the first time then you could try injecting the new LePage's construction cement into any gaps between the wood and the cockpit floor (I can't remember the name of the stuff but it is a moisture cured polyurethane that sets as hard as a rock). It comes in full size cartridges that fit in a caulking gun.

This might be a lot easier than trying to persuade epoxy to flow uphill and glass to stick upside down.

posted December 07, 2007 02:12 PM               

Tailpiper - I measure the end grain balsa which had been attached to the underside of the cockpit floor to be about 3/8" or 1cm thick. It appears to have been glassed over with a fairly thin layer of fiberglass. I've never done fiberglass work before, so tough to say whether its a single layer or maybe 2-3 layers at the most.

posted January 08, 2008 11:01 PM               

I used a 4 1/4" hole saw to do some exploratory work. I'm using 4" deck plates secured with caulk and machine screws to seal the holes. Three holes in the bow area was overkill. Foam was dry and I believe all three holes access the same compartment. Plus this area isn't water tight anyway due to the potty waste line and vent. Any excess water in this area would have drained out the hole for the waste line. In hindsight, one hole would have sufficed.

Access hole rearward of first step into cabin area. Foam in this area was a solid composite of white styrafoam and what appear to be a blown-in hardening foam. I bored a 4" hole down thru the foam (approx 12" in depth) to the hull. Foam at the bottom was somewhat wet. My theory is that excess water from under the cockpit floor penetrated the cockpit forward bulkhead and worked its way beneath the cabin floor. My hope is that excess water will leach back into my access "well" where it can be sucked out and/or evaporate. I may run a fan in this area when it gets warmer to generate some forced convection.

Hole drilled from port quarter berth into compartment beneath cockpit floor. There is a similar hole on the starboard side. Thru these holes I removed 8 gallons of water and ~4 garbage bags of loose foam bricks. Most bricks were wider than the holes and had to be cut up with a steak knife to get them out. It was tough work!

View inside cockpit cavity looking rearward toward stern. The bulk head visible is what separates the cockpit compartment from the lazerate. Prior to removal there were foam blocks stacked beneath the quarter berth and stewn in the center. The foam beneath the quarter berths added rigidity to the fiberglass above. I intend to replace this foam with new closed cell foam logs to restore this rigidity.

View inside cockpit cavity looking forward toward cabin. The bulkhead seen here separates the cockpit cavity from the cabin floor. Thankfully the plywood construction of these bulkheads seem relatively solid despite exposure to excess water, though I haven't probed them extensively. Regardless, there not much that could be done short of tearing the entire boat apart.

View looking upward at the underside of the cockpit floor. The glassed over end-grain balsa can be seen. There are actually 2 sections of this, one on either side of the cockpit floor centerline. One side has delaminated, exposing the rotted end-grain balsa. The other side appears to be relatively intact. Need to take a closer look, possibly only one side will need repair. Also need to see if there is a correlation between greater floor sponginess and the delaminated side.

By default, I feel as though I am becoming quite the expert on this topic. Though I haven't fixed anything yet, only exposed the problems. I'll post more info as I make progress.
------------------
Lee
CL16 #2062
S565 #781

[This message has been edited by lholland (edited January 08, 2008).]

[This message has been edited by lholland (edited January 08, 2008).]

posted January 09, 2008 04:21 AM            

This thread should be bookmarked by all Sandpiper sailors. These pictures will come to be known as the Holland photos.

posted January 09, 2008 08:27 AM               

I am so glad for these photos and your advanced work. I have to do this job this Spring and your info helps immensely.

I presume that you took the last shots by holding a camera inside the cavity?

I am very dubious about doing upside down glass work through a 4" hole while lying on my side in a coffin sized cavity. I am just to old and stiff for those kinds of contortions. Is that still your plan?

Here is my tentative plan, I would welcome your comments as someone who is several steps ahead of me.

I plan to cut out the cockpit floor and remove the foam and water. I will probably cut the walls of the cockpit (maybe about 2" up from the floor ) rather than the floor itself as I think it will be easier to make a fair join in the walls when it is reassembled.

I am thinking in terms of building a lattice of white oak (btw. do not use red oak as it will rot) that is glassed to the hull and is topped by a white oak platform that the cockpit floor can rest upon. The lattice would be filled with flotation foam.

With this structure the load on the cockpit floor would be transmitted through the wooden lattice to the hull instead of to the side walls of the cockpit. I think this would allow me to get away with a less than optimal strength join when I glass the cockpit floor back to the cockpit sides.

This approach will also allow me to raise the forward end of the cockpit floor by a inch or so to enable better drainage in the cockpit.

Regards,

posted January 09, 2008 09:40 AM               

We will be reviewing them constantly as we plan our cockpit floor work.

Thanks for all your in depth work Lee.

posted January 13, 2008 11:21 PM               

Tailpiper - I would estimate the depth to the hull at my bow access holes to be approx 12-16". However, I'll take an exact measurement of all the holes next time I get out to the boat.

Don T - Yes the final shot of the underside of the cockpit floor was taken by sticking my arm and camera inside the access hole. That's the beauty of digital, just take a bunch of pictures and see which ones turn out.

I too am dubious about how much glass work I can do laying on my back thru a 4" hole. May be mission impossible but I do have near super-human patience and am still reasonably flexible. Now that I've got the access holes cut and foam removed, I need to do some serious contemplation of my next move. No firm plan yet.

I have never done glass work, so the idea of cutting out the cockpit floor frightens me. I'd be afraid that it wouldn't go back together or end up looking like a hideous hack job. I'm sure with sufficient planning, skill and patience, its doable. Certainly, removing the wet foam will be simple once the floor is cut out.

Darcy - Not sure what CSI is, but I'll take it as a compliment.

I would recommend that any concerned Sandpiper owner put a single 4" access port into the sealed cockpit compartment. Using a hole saw, it's not hard and you will get a nice clean hole. Then use a deck plate ($15) secured with machine screws and a bead of sealant to cover it up. I estimate it would take 2-3 hours.

Once you have an access port you can get a handle on the magnitude of the problem. Maybe you'll be lucky and it will be relatively dry. If not, at the very least you can stick a shop vac hose in and suck out the standing water. Maybe just leave the foam in place and monitor the cavity periodically for water entry.

Alternatively, you could bore an access hole from the lazerette. A small hole (~1") close to the hull would allow water to drain into the lazerette where it could be more easily removed. Then this hole could be plugged when sailing. My CL16 has a series of 3 plugs separating the various under-floor and lazerette compartments, with the final plug located at the base of the stern. You store the boat with the plugs removed and the boat tipped bow up. The idea is that water that gets under the floor will flow toward the stern and exit the rear most plug.

I hope to report back from the dark side in the next couple of weeks.

------------------
Lee
CL16 #2062
S565 #781

posted January 14, 2008 08:41 AM               

quote:

---

Originally posted by lholland:
Alternatively, you could bore an access hole from the lazerette. A small hole (~1") close to the hull would allow water to drain into the lazerette where it could be more easily removed. Then this hole could be plugged when sailing. My CL16 has a series of 3 plugs separating the various under-floor and lazerette compartments, with the final plug located at the base of the stern. You store the boat with the plugs removed and the boat tipped bow up. The idea is that water that gets under the floor will flow toward the stern and exit the rear most plug.

---

This sounds really tempting for a first shot at draining the water out of the foam.

However, that would not solve the oil panning cockpit floor problem. I think that someone suggested drilling holes through the floor and injecting expanding insulation foam through the holes from the top.

posted January 15, 2008 03:35 AM            

This may not be a handly location for the battery.

posted January 15, 2008 08:13 PM               

If the floor hasn't given way yet, is there any reason not to just glass over the top?

I would cut the 4 inch inspection hole, as Lee suggests, to inspect the structure and dryness. If structure is dry, why not just mix up a bunch of fiberglass slurry and pour in onto the cockpit floor. Maybe even find a pattern to press into the surface as the glass hardens. Could simultaneously tip the boat and adjust the slope of the floor. Top coat with a few layers of epoxy in the correct color.

posted January 23, 2008 08:14 AM               

Note: Be sure to purchase your deck plates first so you can choose the correct size hole saw for your holes. I cut mine too small the first time (4") and it was a pain to try to enlarge them with a slightly larger size hole saw (4 1/4").

Fortunately, I haven't had the need to cut into my CL16, so I can't offer any advice there.

------------------
Lee
CL16 #2062
S565 #781

posted January 23, 2008 12:07 PM               

quote:

---

Originally posted by Tailpiper:
the installation of a 13"x17" hatch into the new floor.

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Tailpiper:

Hmmmm. Interesting idea to use a big hatch. Very tempting route to go...

Do you have a wooden floor to put over the hatch? If not, then do you catch your feet on the hatch?

Anything you would do differently if you had to start over?

TIA.

posted January 24, 2008 10:36 AM               

quote:

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Originally posted by Tailpiper:
Hi, [b]Don. No, there are no issues with this installation. The hatch is the walking surface and it poses no problems...[/B]

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Ok. That sounds great and that is my new plan. I can see getting this done in a reasonable amount of time without much damage to my body.

Off to measure my cockpit and search the web for a suitable hatch.

Thanks very much.

Don.

PS. Now if I could install a porta-potti down there then that would solve two problems

posted January 29, 2008 11:17 PM               

The ones that had cored decks generally proved to be extremely strong. An older boat might require some repairs to the core but once that's done you've got yourself one really fine tough boat.