Sealing rub rail

dutch123 · Posted: Wed Jun 20, 2012 11:45 am Post subject: Sealing rub rail

I had a small section of the rub rail coming loose on the port side stern and after reattaching I wondered what is actually sealing the rub rail to the hull?

Captains Cat · Posted: Wed Jun 20, 2012 12:31 pm Post subject:

Are you talking about the metal and the rubber, or just the rubber?

The rubber just fits in a dovetail groove. If you lift a small length of it out (start at a seam), you'll see the pop rivets that hold the metal part to the hull. If you look up in the berthing area inside the boat, you'll see some covered "lumps" which are the other side.

If a pop rivet has broken, you can put a new one in near it, or drill the hole out a little larger and replace with a bolt.

Charlie

dutch123 · Posted: Wed Jun 20, 2012 12:56 pm Post subject:

Yes, thank you Charlie, I'm aware that the rub rail is attached with rivets but I'm not sure if the entire rail should be sealed to the hull so water will flow over it not through it. I sealed the new rivets but I just don't like the fact that water could penetrate the hull in this area and it would be hard to see with the fasteners hidden under the rail. Is there a good reason why I shouldn't seal the entire rub rail top and bottom to the hull?

thataway · Posted: Wed Jun 20, 2012 3:46 pm Post subject:

Most C Dorys have the rivets which hold the railing on, covered with epoxy or some other resin sealant. The hull to deck joint itself is glassed together.

Many folks use a clear silicone sealant under the black rub rail under the black vinyl and between it and the Al extrusion. Under the Aluminum it would probably be best to something like boat life, Life Caulk. The rivet could be put in place with that compound.

Tad and Toby Jackson · Posted: Thu Jun 21, 2012 8:19 am Post subject:

Dutch 123,

We had the same problem on our 95 Cruiser. I think the only way to take care of the problem for the long term is to remove the rivets and rub rail altogether and then re-install the rail with through hull bolts, washers and nyloc nuts. I don't care how well you try and seal the top and bottom of the rail with caulking, water is still going to get behind the aluminum rail, move to the rear and settle at the lowest point of the rail as the boat sits on the water and then....corrosion WILL occur to the rivets. Replacing the rivets with ss bolts allows you to seal that hole through the hull with 4200, so any water behind the rail will not penetrate the hull. I tried to seal the top and bottom of the rub rail with silicone caulking at the joint between the aluminum rail and the hull and even though I had cleaned that area well, the silicone soon began to break free and allow water behind the rail. This water would continually leak out of the bottom of the rail through breaks in the silicone, but slowly...I would see water marks for days after the boat was out of the water. Eventually, I removed the silicone from top and bottom which allows any water behind the rail to drain from the bottom of the rail. Pictures of the project are in our album.

Tad

Sunbeam · Posted: Thu Jun 21, 2012 11:18 am Post subject:

I haven't re-done a C-Dory rubrail specifically, but on pieces of this type, I favor sealing the holes and/or bedding underneath, but then just letting the rail sit as installed (meaning, not sealing along the length on the outside). The long seal usually seems prone to failure at which point you have a long water channel with gaps. Also the caulk can become unsightly. Re-doing it all is a chore.

In a similar way I prefer to caulk under window and hatch flanges but don't run an additional bead around the outside. If I see one added I often wonder if someone was attempting to solve leaks without rebedding (underneath).

I have one place where the metal rubrail base has pulled away (or was perhaps installed "un-snug"), and I'll probably re-install it with some bedding and a machine screw (but I have not disassembled it to investigate yet).

dutch123 · Posted: Thu Jun 21, 2012 11:46 am Post subject:

Ok yes, thanks for the advice all. I will leave rail as is.

srbaum · Posted: Thu Jun 21, 2012 9:12 pm Post subject: Rub Rail Issue

I concur with Comfy Dory.
I purchased my 22 Cruiser several years ago knowing that the rub rail was detached mid-ships both port and starboard. I found that salt water was sitting in the area of each caulked rivet in the hull and was being corroded by the salt water, so no matter what I did, the only good fix was to drill out all of the rivets and install SS machine screws and washers with nuts on the inside. I used nylock nuts on the inside, except where fasterners were visible. The visible areas received cap nuts. I used 4200 sealer for the installation of the fasteners and rub rail.

NCPete · Posted: Thu Jun 21, 2012 9:19 pm Post subject: Lost end piece of the rub rail

Last weekend when I pulled the anchor it stuck the finish end piece of the rub rail. This is a small black triangular plastic piece that is pressure fitted into the end of the rub rail to give a finished appearance.
Does anyone have suggestions where I can my buy one? (2000 22 Dory).
Thanks,
Pete