deck joint fix

deckhand · Post by **deckhand** » Wed Aug 29, 2007 12:36 am

Well after being a lurker for 2 years a few things changed. 1) I actually bought a boat and 2) I decided to stop lurking.

So I have a question about deck joints. They seem to be a hot topic and most fixes are done because the whole thing has failed, but what if your joint hasn't fully failed, just the sealant? I have the full details on my site

www.dkyrejko.com/hobyn

I'd love to just expoxy and glass the thing over but wanted a few ideas to kick around too. Thanks guys.

Quetzalsailor · Post by **Quetzalsailor** » Wed Aug 29, 2007 8:49 am

Some older boats had bolted and glassed-over hull deck joints. Our 1970 LeComte North East 38 is that way. I think Hinckley Bermuda 40s were. too. It's basically a labor-intensive, unpleasant, time consuming task that's tough to do neatly and it shows that way in our boat. Sitting here 120' up in an office cubicle, I cannot remember for sure whether all the toerail bolts are visible (they are aft, in the lazarettes, but forward I think they're concealed). The Morgan 27 has a bolted and sealant joint and they were so confident that it wasn't going to flex that they gel-coated over it at bow and stern (concealed under toerails for most of the length).

So, there's nothing intrinsically wrong with the idea. If you encapsulate the existing bolts I'd suggest adding enough new tabbing to make the bolts redundant; you won't be able to verify their condition, crevice corrosion and all, so you might well be happy to think of them as old assembly aids only.

I think I saw that you've removed large portions of the liner. Are you confident that you're putting back enough structure in new woodwork to compensate for the loss of the structure that the liner provided? Certainly, modern boats depend upon their liners; a 1970 boat may not.

Were the balsa-cored stringers above the waterline? If so, how'd they get wet inside?

Looks like you're doing lovely woodwork!

Ceasar Choppy · Post by **Ceasar Choppy** » Wed Aug 29, 2007 8:49 am

Hi Dave and Welcome! Nice blog you got there.

One thing to consider with HTD joints is that a boat hull is flexible (just a little) which is why I'm sure they used caulk in the joint. Fiberglassing the whole thing may be more trouble than its worth if there is no give. I think we discussed this here not long ago...

How bad is the leaking?

Rachel · Post by **Rachel** » Wed Aug 29, 2007 11:31 am

I don't know how equally this applies to all hulls/decks, but I believe there are enough hull-to-deck joints that are "solid" (i.e. don't allow for flex), to show that it can be okay. For example, I don't believe the Triton has any flex allowed for there - I think it's held together, rigidly, by fiberglass only and no fasteners (but I know I'll be corrected if I'm wrong).

The Rhodes Meridian (24'9" boat that's similar to a Triton or Ariel) definitely has a hull/deck joint that's held together only by fiberglass tabbing (on the inside), and if there is flexing (which I'm sure there is), it's done by the whole boat as a unit, and not as two separate pieces.

I believe the Triton has what is essentially a "butt joint" between the hull and deck; the Meridian has a hull that turns the corner to become parallel with the deck, and then the deck sits on top of it, and there's a ~2-3" overlap of horizontal fiberglass which is then glassed over.

What's the cut-away profile of the T-30 joint, do you know?

Is the liner structural on that design? (I'm not sure how that might affect the overall situation of the joint.)

And welcome to the board! :-)

Rachel

deckhand · Post by **deckhand** » Wed Aug 29, 2007 9:52 pm

Thanks for the input, I can see where lack of flex might be a concern, but considering that I just replaced a 12" section of the joint with all new glass and epoxy I might have another problem. The new joint section is WAY stronger and stiffer than the old section. Where the old was 1/4" overlaps bolted, sealed with caulk and fiberglass tabbed on the inside, the new joint is almost 1/2 of biax cloth that overlaps onto the deck and hull and is tabbed inside to a new piece of stringer.

sounds like I need to take another look at my flexing...

as for the leaking, I've never sailed the boat, I'm only going but the water stains, dust trails and rotted stringers. It looks like ice popped the stingers and some of the tabbing on the inside. The leaking joint allowed water to drip, drip, drip onto the breaks and eventually rot struck. All stringers are well above water. Either that or the whole boat was full at one point... yikes

What about grinding down the head of the bolts, digging as much sealant out as possible, grinding it out a bit, using a bunch of strand filled epoxy and laying a single layer of biax over the top. Fairing the whole thing flat and putting a new wood rubrail on that fully covers the whole repair (figure 2-2.5 inches high). Then grinding off the exposed bolts to the nuts and doing the same thing on the inside?

Quetzalsailor · Post by **Quetzalsailor** » Fri Aug 31, 2007 9:07 am

Don't bother grinding the bolts off. Too time consuming, too messy, too many chips in the face and hair, too noisy, too much heat applied to the adjoning 'glass.

You might use your Dremel to clip the excess bolt off to make it easier to 'glass over. You might pull 2' worth of bolts out and rough 'glass in sections. You're gonna' have to grind to get a clean surface, too.

deckhand · Post by **deckhand** » Fri Aug 31, 2007 9:55 pm

Too time consuming, too messy, too many chips in the face and hair, too noisy, too much heat applied to the adjoning 'glass.

this is a boat rebuild, I've been grinding glass upside down in a bunny suit in 90? weather for weeks now. A few face shield blocked chips, and extra time on the job is fine with me as long as it makes for a better job.

My question is if the bolts are going to interfere with the layup and if I should try to fair the whole thing before or after I lay the glass (ie. lots of thick, fiber rich putty with a layer of glass on top, or a layer of glass with a little putty and faired on top)

There seem to be two schools of repair, the "just keep it sealed" and the "build it stronger" groups. I'm part of the latter but like I said, I'm worried about using too much putty on the joint and having it fall off. But with the bolts there I might not get a good enough bond because the cloth will just bridge them...

Post by **Tim** » Sat Sep 01, 2007 6:27 am

You'll get a better fiberglass job if the surface is as smooth as possible. To me, this means removing the offending bolts, if your new structural plan precludes their necessity.

deckhand · Post by **deckhand** » Sat Sep 01, 2007 12:11 pm

I had a crazy idea this morning, what if I built up the glass around the bolts and then laid a layer on top too. Figure, grind down the tops of the bolts to about 1/16th of an inch of the surface, lay down some 15oz biax with holes cut into it, and then glass a layer on top of them. The holes could probably be punched no problem with a piece of sharpened and heat treated steel pipe, and since the bolts are laid out in a spacing pattern, I could make up a hole pattern as well.

Like I said, crazy idea.

Tim, if I take out the bolts, should I pry the joint apart and clean out the dried up goo or just glass the whole thing over?

Post by **Tim** » Sat Sep 01, 2007 1:35 pm

If you're going to glass it over, the fiberglass takes over the structural reinforcement for the joint, thereby replacing the bolts and whatever sealant/adhesive is in the joint as currently existing.

So unless the goop is external and therefore potentially in the way of your fiberglass work, there's no need to go to great lengths to remove it from the existing joint.

deckhand · Post by **deckhand** » Sat Sep 01, 2007 8:15 pm

wonderful news, it's a healthy sized lip and cleaning it out would have been a bear of a job. As I was cleaning up the joint today in prep for the repair, I found myself grinding through almost 3/8" of gelcoat in some areas. No wonder the joint disintegrated in the accident, the lip is nice an thick in some areas and just a lot of faired up gelcoat in others! three cheers for biax tape...