Deck joint-Who, What and When

[Scott Galloway]

The two bulkheads that define the forward end of the main salon and the aft end of the V berth area on my boat (Ariel #330) are both made of plywood.  In 2004, I removed the standing rig and the original badly corroded chainplates. Over the years, leaks at the chainplate slots had caused water damage to the deck at the chainplate slots and at the top of the bulkheads and also to the bulkheads where the bolts holes penetrated the bulkheads.

I  enlarged the bolt holes in the bulkheads and augured out the bad wood between the upper and lower laminations of the deck, I then filled these areas with epoxy and or fiberglass. I also removed all soft wood in the bulkheads and repaired these areas with fiberglass. I purchased new 306 stainless steel chainplates and bolts and installed them. The new bolt holes were drilled throug the enlarged epoxy or fiberglass filled holes, so there is no plywood to bolt contact. Also, the top of those two bulkheads on my boat were not taped to the underside of the deck, so I did that as well.

With the help of a professional, the strong back beneath the mast on my boat was rebuilt at the same time. I have documented the stong back project elsewhere in this forum. Also, you can visit my webpage on that project. That web page provides photo documentation of the strong back project:  http://www.solopublications.com/sailarir.htm.

My strong back upgrade was unpopular with some contributors to this forum, but in my opinion and in the opinion fo the professional who designed and completed the project, it was the right solution for the problem that my boat was experiencing. It has been 19 years since that work was completed, and the reinforced stongback has performed very well in the Monterey Bay and Pacific Ocean environments where I sail my boat.
 
I have not experienced soft wood in the port or starboard V  berth shelves or in the port side storage cabinets, So I can't say for certain what kind of wood those shelve are made of, but I have assumed that are also mode of plywood.

By the way, I have taken photos beneath the deck of cabin sole, which demonstrate that the plywood used in that area is labeled as AC plywood and not as marine plywood. (Please see attached photo.) When I removed some of the formica covering the bulkhead at the forward end of the main salon, I discovered prominent voids in the plywood, So if the top edges of your bulkheads are not sealed in some way, water entering that area may find its way down through the voids in the plywood. This could result in more than cosmetic damage to the bulkheads.

 I also removed and re-bedded the the rub rail and re-bedded the hull desk joint in 2002 shortly after purchasing the boat. That was a major project that took a number of weeks. A prior owner had removed the original caulk and replaced it with what appeared to be silicon caulk. I had to remove that material from the seam, and then clean the joint with solvent. My hull/deck seam is now bedded with 3M 5200. The hull deck joint is gassed over with roving and mat on the inside of the boat. The joint itself was not leaking into the cabin on my boat, however, a prior owner had re-fastened the rub rail with long screws that penetrated the seam, and the roving and mat as well. The protruding screws were rusted, and rust stains ran down there inside of the hull, I filled all of those screw holes with epoxy from both the cabin side and from the outside of the hull. I then rebedded the hull deck seam with 3M 5200. I used 3M 4200 to bed the rub rail, which I also fastened with shorter screws that did not permit water intrusion.

Even with a sound and well sealed hull to deck joint, you may and probably will experience some puddling of rain water on the V Berth shelves near the chainplates. The key to stopping that problem (at least temporarily) is an annual or semiannual re-bedding of the chain plate covers to prevent rain water from entering the chainplate slots. I use a polysulfide caulk for this purpose.

As far as removing the shelves in the V Berth area, I do not know whether those shelves are designed to stiffen the hull, but they probably do provide some structural reinforcement. You might write to Ebb. Ebb has done seem extensive redesign and rebuilding of the interior of his Ariel, which is well documented on this forum.

[Rob Rotondo]

Thank you Scott. I will look up Ebb's stuff.  I would post a few pictures but I'm not sure how