Rivets missing on rub strip

R

Ron C

New member
I'm in the process of buying an older C-Dory 16 and need some advice about replacing some rivets that have pulled out. I suspect that a new rivet would not hold in the same enlarged hole.
Would a small molly bolt be a good alternative?
Does the rivet hole need to be sealed or does the rubber strip seal adequately?
If the rubber strip is damaged should I cut and splice or replace the whole thing?
Thanks in advance,
Ron and Sally
 
Probably the most comprehensive work on this was by Sunbeam:

Where she replaced many of the rivets.

Doing a search for "rub and rail and rivets" will bring up at least half a dozen threads on the subject.

Basically the best way to go is to completely drill out the rivet, and then replace it with SS Rivet or small bolt/nut. The originals were covered with a dab of sealant or epoxy. Would definitely seal the rail and rivet--the vinyl strip is not adequate. Also water may get inside of the aluminum channel.

I would not use a Molly bolt.

I would be tempted to pull the entire rub rails, buy an air rivet gun, and lay on the rail, with sealant under neath, popping in the rivets fairly quickly. Then go in and epoxy dab over each rivet. Then a new rub rail, if the old one is shot. [/url]
 
I, like many others, had to replace all the rivets on Journey On's rub rails. It was a hard job.

Here's what i learned. 1. These rivets join the hull and deck, so they're critical. 2. You have to remove ALL the rivets, not just replace the missing ones. 3. Some rivets go through and are visible from the inside, others are blind holes or you can't get to the backside.. 4. Drill the heads off the ones that go through the joint and punch the shank out. That includes the the ones you cant get to the back, the rivets will fall in the bilge and you can get them later. 5. One has to drill the blind rivets out. The problem is that the rivet's center pin is hardened steel, so you just cant drill the rivet out. 6. My solution was to drill next to the pin, which gave a larger hole and extract the rivet. 7. Fill the blind holes and those you can't get to the back, both kinds, with thickened epoxy and let set. 8. For the holes where you can get to the inside, use a Phillips head bolt, stainless washer, hard nylon washer (stainless and aluminum aren't compatible) and 5200. 9. Fill the hole with 5200, push the bolt/washer through, have your helper hold the bolt with a screwdriver and on the inside use a stop nut and washer, tightening the assembly. Clean off excess 5200. 10. For the filled holes, drill a pilot hole, install and remove a sheet metal screw. Fill the hole with 5200, install a Phillips head screw, metal washer and a thin plastic washer. Tighten. 11. Re-install the rubber bump strip with screwdriver and rubber mallet.

I ordered all bolts, screws, washers from boltdepot.com. You can get the stuff you need in 316 stainless. I used #12 bolts/screws. The rubber strip has a few bumps from where the bolt/washers didn't sit straight, but that's life.

The job takes a lot of beer. Your wife takes several weeks to speak to you, again, but you won't care. No boatyard is interested in doing the job, at least in SoCal.

Boris
 
Boris,
Most of our C Dory's have the butt joint hull to deck joint glassed on the inside (instead of a Shoe Box type of joint)--and don' depend on the relatively weak fastening of the pop rivers or similar as some boats do. To me, the glassed hull to deck joint is one of the main beauties of the C Dory giving it superior strength.

I would try and get the profile of the head of any bolt I put inside of the rail extrusion to lie inside of the void in the vinyl extrusion. There are several ways of doing this, including using flat heat, slightly smaller bolts, and chamfer the hole in the rail extrusion to match the bevel of the flat head bolt. I had good results using Tef gel at an aluminum/SS interface in the past. But there are a number of ways to do it.
 
I too was always under the impression that the upper deck and hull connecting seam was glassed and sturdy enough to allow the total assembly to be pulled from the mold. Did things change later on? It was always a selling point in the earlier literature.
 
The post was intended to describe how I replaced the rivets on my boat, your method may vary.

However, I thought that the rivets went through the hull/deck overlap. Was I wrong? If they do, they might serve two purposes: to keep the rub rail on and strengthen the joint. Your choice.

Again, the main intent of the post was to describe the rivet replacement. If I did anything wrong there, I'll be glad to learn the correct way.

Boris
 
Boris, you are correct that probably the many of the boats built in S. Calif, used the "shoe Box" where the deck mold was slightly wider/longer than the hull mold and it was slipped over, with some bedding compound or even "glue" then pop riveted to give "strength"--and as you pointed out, when these fail--the hull to deck joint fails. Fortunately C Dory was a bit smarter and glassed the H to D joint. There were also a few boats which had an "H" section of aluminum changel, with the cabin and deck slipping into the top and the bottom slipping into the bottom of this extrusion--then Pop rivets held the pieces in place, so all of the structure was held by pop rivets.

There are several ways to replace the rivets--including bolts, pop rivets, and using a structural adhesive to keep the channel for the rub rail in place. Probably the worse method of hull to deck, was when screws were placed into pieces of wood inside the boat, and if the wood split, had rot, or the threads loosened--then "Pop" goes the joint! There were some catastrophic failures with this method.
 
Bob, I think that the question in this blog is replacing the pop rivets that go through the rub rail/hull/ deck. I described the method I used to replace the rivets and I hope that's all I did. I do hope that Ron and Sally aren't scared off by the comments about the joint.

Another topic, perhaps another blog, is the joint between the hull and deck. My only comment I had/have is that the rivets go through a structurally sensitive area of the hull/deck at the same time thy are holding the rub rail on. I don't care how they did it in the past, I wanted Ron and Sally to be careful in replacing the rivets and understand that I could not easily drill them out with a small drill.

I understand that the factory now has a different method of fastening the rub rail. I don't know what they do. If someone does know, I'd be glad to learn. I hope they don't use pop rivets cause they were a bear to replace.

Boris
 
I did not think it was such a hard thing...took me several days but I work slow..
I used tapered head stainless steel threaded screws, with a SS washer and a nylock nut...worked fine ...that is until I ran out of washers and the damm local (mountain) hardware store wanted $1.10 per washer...I told them to pound sand...I went to the bank...got a large hand full of half dollars...drilled a hole in the center of each and used them as washers...about the same size and it entertains me when I look at em...guess you could have used quarters ...but halves look better.....it was fun...I used soap to get the rubber strip back in place and that made the job easy...

Joel
SEA3PO
 
Thanks Dr. Bob and others for your input. Don't have the boat home yet but will start locating bolts, etc based on the info provided by the C-Brats community.

2016 fishing boat ( Miss Take)
1999 C-Dory 16 cruiser (See-Saw)
 
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