Hull deck joint screws or bolts?

[labestia]

In the process or taking care of water coming in through the deck-hull joint, I’ve lifted the cap and rub rails (what a nightmare ).

The joint is held together with self drilling screws; since I’m at it, can or should I change those screws with through bolts with washer and nuts?

Is this a sound idea or an unnecessary overkill?

La Bestia

[ulferlingsson]

In my old boat someone had already taken it apart, removed what appears to have been original stainless steel blind rivets, and screwed it together with stainless steel screws. Too long, so they then had to be cut.

In some places, like the transom, I see a problem with strength, so I put glass fiber mat across the joint to lock the transom in place, and to avoid that the aft stay bends it in. I did the same at the plates where the shrouds attach - "röstjärnen" for you who speak Swedish. And I was thinking, why don't I just run glass fiber of the whole joint, make it stronger, and get rid of that potential source of leakage once and for all.

Can someone give me a good reason NOT to do it?

[mdbee]

Screws?? What kind of boat? Mine has SS bolts about every three inches and she's only a 26 footer.

Originally Posted by labestia

In the process or taking care of water coming in through the deck-hull joint, I’ve lifted the cap and rub rails (what a nightmare ).

The joint is held together with self drilling screws; since I’m at it, can or should I change those screws...

[mdbee]

If you have the time, go for it. I cleaned mine, shot in some 5200 and tightened all my bolts.

Originally Posted by ulferlingsson

In my old boat someone had already taken it apart, removed what appears to have been original stainless steel blind rivets, and screwed it together with stainless steel screws. Too long, so they then had to be cut.

In some places, like the transom, I see a problem with strength, so I put glass fiber mat across the joint to lock the transom in place, and to avoid that the aft stay bends it in. I did the same at the plates where the shrouds attach - "röstjärnen" for you who speak Swedish. And I was thinking, why don't I just run glass fiber of the whole joint, make it stronger, and get rid of that potential source of leakage once and for all.

Can someone give me a good reason NOT to do it?

[scottyt]

depending on the type of joint you might really need to glue the joint with 4200, 5200 or epoxy.

if its a shoe box, ie deck turns down over the hull. then pack the joint with any of the above and tighten it down. if your hull is cored do not just put glass on the inside, you need to stop the water getting in to the glass, seal the out side.

if the screws are stripping then yes change them to bolts, but that is a big job.

you might need to take the tension off the rig so it does not try to lift or deform the hull and deck as you change the screws out.

give us some pics of the nightmare

[Northeaster]

Mine also had stainless rivets, but was glassed as well, on the inside. When I separated the seam outside, after drilling out the rivets, I was able to clean it, put new 5200 and through- bolt every 4", I used stainless steel machine screws (bolts), with tapered heads, and low profile nuts. I could not use nyloc nuts, as there wasn't enough room for them, in order to be able to fit the trim back on.
I used lots of 5200 on the thread screws, so the nuts are not going anywhere.

My boat had sailed for 25 + years with stainless rivets, and light glassing on the inside, but I always try to put it back together stronger than it was before.

Do you have any pics of your project? Is there room to for nuts underneath, or is there a protective rail that fits tight?

If possible, I would throughbolt. Doesn't cost that much, not take much extra time.

[sailingdog]

Screws or rivets were pretty common as a method of fastening the Hull-deck join. In many cases, the screws and rivets were in addition to an adhesive or sealant—especially on newer boats. Also, on some boats—especially with an outward flange—the interior of the joint is glassed over as well. So, the screws and rivets may or may not be providing the bulk of the strength for the attachment.

Originally Posted by mdbee

Screws?? What kind of boat? Mine has SS bolts about every three inches and she's only a 26 footer.

[jrd22]

No question bolts are better, with fender washers under if there is room.

[Maine Sail]

Originally Posted by labestia

In the process or taking care of water coming in through the deck-hull joint, I’ve lifted the cap and rub rails (what a nightmare ).

The joint is held together with self drilling screws; since I’m at it, can or should I change those screws with through bolts with washer and nuts?

Is this a sound idea or an unnecessary overkill?

La Bestia

They are likely the reason the joint is leaking in the first place. If there were no movement even the worst bedding compound should have held up fine. If the screws are the only mechanical fastening, no glass tape inside, then I would re-do it with bolts or at least bolt, screw, bolt. It is amazing what corners were cut by some builders...