Rub rail - slit behind rail

[Major Tom]

I had 9 of the rub rail rivets come loose on the forward starboard side, and am repairing it. My boat is a 2005 CD22 and it has the slit behind the rub rail, running the length of the rail, as far as I can tell. The rivet holes are in line with the slit, and the slit isn't very deep, from what I can tell, maybe 1/8"-1/4". I think I read in one of the posts about some boats having the slit, but I can't find it again and can't remember the detail. Anyway, should I leave the slit as-is, or try to seal it with 4200 or 4000? Seems like water will definitely get in there due to that slit and will corrode the rivets? OTOH maybe the slit will allow it to dry better? And I can't remember the purpose of the slit, other than possible drying, I can't see the advantage. For now I'm just repairing the 9 broken rivets to get back on the water, but at some point I'll need to take both rails off and do them all with SS screws/bolts.

Thanks to Sunbeam's excellent write-up and some others, it's going pretty smoothly. FWIW, some of the caulk blobs were very hard, probably glassed over. They were difficult, I had to use a hacksaw blade and a small sheetrock hand saw to carefully wear down the thin layer of glass. I tried a small grinder attachment for a drill but it was too easy to go too far. After gently tapping from the outside with a punch, then going back inside to trim the now-slightly-raised glass and caulk, I got them off.

I started with 8 broken rivets but as I was working with the rail I pulled it out just a bit too far and the 9th one pulled out from the outside, even though I hadn't touched it. But it didn't come off the rivet head like the others, the whole thing pulled right out. And instead of a thin rivet rod and mandrel like the others, the aluminum rod part that goes through the hull was deformed and much larger than the others... almost like a blob of aluminum. Maybe it mushroomed somehow, which is odd. Or did the factory use some kind of "blob rivet" that was sealed in the glass? Luckily I was able to chisel off the rivet head and separate the mushroom and drilled a clean hole for the new screw.

Thanks for the help!
Tom

 

[Major Tom]

I took a closer look at the slit, and I answered my own question, at least on that part... the slit is only about 1/4" deep, and by simply sealing each hole well before inserting the screw, my new screws will be well protected. But for the old ones, well, I'm sure I'll be taking both rails off completely one of these days and redoing them all... it's far too easy for water to get in that slit and stay there.

But I'm still curious as to its purpose, it's effect on corrosion, and the "blob" mushroomed rivet. If I'd been tapping too hard I could see it would mushroom like that, but I didn't tap that one at all, it just pulled out with very moderate force, from the outside of the boat. Hmmm.

Also, in case it helps anyone else, most of my screws are ending up to be 1.25", not 1" as many have said. If you're ordering in advance of tackling the job, so you can't really measure yet, order some of those too and maybe even 1.5".

 

[tsturm]

I took a closer look at the slit, and I answered my own question, at least on that part... the slit is only about 1/4" deep, and by simply sealing each hole well before inserting the screw, my new screws will be well protected. But for the old ones, well, I'm sure I'll be taking both rails off completely one of these days and redoing them all... it's far too easy for water to get in that slit and stay there.

But I'm still curious as to its purpose, it's effect on corrosion, and the "blob" mushroomed rivet. If I'd been tapping too hard I could see it would mushroom like that, but I didn't tap that one at all, it just pulled out with very moderate force, from the outside of the boat. Hmmm.

Also, in case it helps anyone else, most of my screws are ending up to be 1.25", not 1" as many have said. If you're ordering in advance of tackling the job, so you can't really measure yet, order some of those too and maybe even 1.5".

There are pop rivets that split into 3 Big legs when the mandrel is drawn out? Kind of like a wall molly for drywall. :beer

I used stainless 3/16 X 3/4 pop rivets with a back up washer on the inside sealed with 5200 when I did mine 12 years back :thup

 

[Major Tom]

Well it doesn't split into 3 legs but it had mushroomed pretty well, apparenlty. Anyway, I got those finished for now and can get back on the water, let's hope the other's don't start pulling out,a t least until Fall! But I can see that I'll need to pull both rails at some point and replace all those rivets.

 

[colbysmith]

Resurrecting this thread, as it seems to be more recent than the ones from 10 years ago. I had the tailend of my starboard front section of rub railing pop away from the boat last week. This was just about under my forward cleat, or next to the cabin helm. Pulling the rubber insert out, I found that the vast majority of the rivet heads were popped off, so I drilled out the few remaining and pulled the rail off. The only thing holding the railing on, other than about half a dozen rivet heads, was just the rivet bodies. I did see Sunbeam's write up from I think 10 years ago. The material on the inside of the riveted areas in the cabin, is more glass, so I don't think I'll really be trying to hammer the rivets into the boat. Tomorrow I'll plan to drill all the rivets out, from the outside. And probably go all the way thru into the cabin. This section is very easy to access from inside the boat, as it's beside the helm and then along the starboard side in the V-berth. I'm guessing the best repair will be to use ss machine screws and acorn nuts. Or nylon lock nuts. And put a generous amount of sealant on the screws where they go thru the hull. Then again, I kind of like this idea:

I used stainless 3/16 X 3/4 pop rivets with a back up washer on the inside sealed with 5200 when I did mine 12 years back

Any other suggestions or advice appreciated. Colby

 

[thataway]

A good way to remove enough of the inside material over the inside end of the pop rivet is to use either a Dremel or Rotozip with a flexable shaft and cutter head to remove the material to expose the end of the the pop rivet. That way you can tap the pop rivet to the inside. and avoid trying to drill them out. I would put some tufgel under the head of the rivet, to decrease the reaction between the SS rivet and aluminum rub rail channel.

 

[ssobol]

Resurrecting this thread, as it seems to be more recent than the ones from 10 years ago. I had the tailend of my starboard front section of rub railing pop away from the boat last week. This was just about under my forward cleat, or next to the cabin helm. Pulling the rubber insert out, I found that the vast majority of the rivet heads were popped off, so I drilled out the few remaining and pulled the rail off. The only thing holding the railing on, other than about half a dozen rivet heads, was just the rivet bodies. I did see Sunbeam's write up from I think 10 years ago. The material on the inside of the riveted areas in the cabin, is more glass, so I don't think I'll really be trying to hammer the rivets into the boat. Tomorrow I'll plan to drill all the rivets out, from the outside. And probably go all the way thru into the cabin. This section is very easy to access from inside the boat, as it's beside the helm and then along the starboard side in the V-berth. I'm guessing the best repair will be to use ss machine screws and acorn nuts. Or nylon lock nuts. And put a generous amount of sealant on the screws where they go thru the hull. Then again, I kind of like this idea:

I used stainless 3/16 X 3/4 pop rivets with a back up washer on the inside sealed with 5200 when I did mine 12 years back

Any other suggestions or advice appreciated. Colby

Unless you can remove the interior furnishings, there will be some existing rivets that you will not be able to get to the interior side of. You will need to use some sort of blind fastener in those spots.

 

[colbysmith]

Just finished drilling out all the rivets. 29 of them. Didn't want to go the route of grinding down the material inside and pushing the rivet bodies through due to dust cleanup then. Probably going to go the machine screw/washer/nut route, but will decide that based on what is available at the hardware store today. Colby

 

[colbysmith]

Finished up reinstalling my rubrail today. I ended up using ss machine screws, washers and nylon lock nuts. 1/4 x 20 x 1 1/4". Here's some photos of the job.

First two photos of the rub rail with the rubber insert removed, where you can see the majority of the rivet heads were popped off.





Next two are with the rail completely removed.





I drilled out the rivet bodies, and then used the screws/washers/nuts to reinstall the rail.




Then used a screw driver to slide along the top of the rubber and rail and pushed the rubber back in to the track. The bow cover piece is missing in these photos, but was placed back on.




I used some 4000 sealant I had to seal each screw. Also put a bead in between the two layers of fiberglass (sole and gunnel).

Last two photos of the washers and nuts inside the cabin.

 

[Xtraplus18]

Excellent job Colby

Looks like the best way to go with screws to replace the rivets.

 

[thataway]

The important thing is to use tuf gel under the SS fitting to cut down on corrosion/metal interaction, and to use enouth sealent (one of the 4000 series products) to be sure there is no leaking. Sealing over the internal fitting as done by the factory is optional, but it does give some further waterproofing.

Colby, how did you use the machine screws and nuts behind the outboard wall in the head? and along the cockpit combings? Those are areas which are very difficult to reach with Screws, and most folks use pop rivets there. I prefer SS pop Rivets--I have a riveter I use mostly with SS, and it is a bit more powerful than the one usually used with alumium pop Rivets.

 

[colbysmith]

The important thing is to use tuf gel under the SS fitting to cut down on corrosion/metal interaction, and to use enouth sealent (one of the 4000 series products) to be sure there is no leaking. Sealing over the internal fitting as done by the factory is optional, but it does give some further waterproofing.

Colby, how did you use the machine screws and nuts behind the outboard wall in the head? and along the cockpit combings? Those are areas which are very difficult to reach with Screws, and most folks use pop rivets there. I prefer SS pop Rivets--I have a riveter I use mostly with SS, and it is a bit more powerful than the one usually used with alumium pop Rivets.

I was not able to find any tufgel at Ace, Menards or Farm and Fleet. I thought about using some dielectric grease, and forgot to, instead using the 4000 sealant. I debated on using aluminum pop rivets, but know those are not as strong as stainless steel. SS rivets of that size (1/4") would be a bear to pop. If I did use rivets, I'd prefer to place them from inside for a better appearance. I could probably have gone with 3/16" diameter rivets, using a backing washer, but they would have to have been a minimum of 1 to 1 1/8" long.
Regardless what I put between the ss screws and the aluminum rubrail, it would squeeze out under pressure when tightening the nuts. I'll take my chances with so many other areas that involve various metals.. In the end, I think the screws/nuts worked out best. Stronger attachment and maybe easier to remove if the need ever arises again.

From my post 3 days ago:
"I had the tailend of my starboard front section of rub railing pop away from the boat last week. This was just about under my forward cleat, or next to the cabin helm."

The majority of the nuts were very easily accessible beside the helm and through the V-berth. Had to do some reaching under the sink around my water heater, and then the last 6 nuts or so at the bow required sticking my head into my anchor locker. :| I put Rosanne to work holding the screwdriver while I tightened the nuts.

I pressure washed the boat yesterday after everything was done and put away. And then we had some heavy rain last evening. No leakage anywhere, so I'm pretty sure I got enough sealant around the screws. 8) Colby

 

[colbysmith]

I did get a return call from Greg at NWMI this morning. He said he would have recommended exactly what I did. That is to use the machine screws and nuts. He said that when they took over in 2009, that they started using screws to attach the rub rails and then put some extra fiberglass over the inside where they may have poked through. Colby

 

[pcg]

The important thing is to use tuf gel under the SS fitting.

I ended up ordering a Tef-Gel product, and not TufGel. After some research I concluded that you intended to mention Tef-Gel, and not TufGel. I hope that's correct because that's what I ordered. The Tufgel products I found didn't appear to have any anti-corrosion properties.
Thank you for the suggestion!
https://www.amazon.com/dp/B00CEF65T4?re ... asin_title

 

[thataway]

Colby, thanks for catching my wrong product (Tef Gel, is what you want for Aluminum and SS). I have also used the Tufgel, and I should have not relied on my memory, and looked up which of the two it was!.

One day in isla Mujeres,(Yucatan Mexico) I spent 3 hours up the mast of another cruisers boat. He had gotten too close to a tall ship, with a long bowsprit, and had damaged his mast near the top. I had a machine shop locally make 6 steel splints, (1/4" x2" x 36"), They drilled about 20 holes in each one, and I held each in place, put "tef gel" under the machine screw head, and tighted up the splints after drilling and tapping each hole. I told the guy it was safe to sail the 500 miles or so to Houston, but not use the Spinaker, and keep the main sail across the splint--use only the working jib, to avoid further stress on the mast. He wrote me a few weeks later after we were both home--"thanks the trip home was uneventual", he had used the spinaker most of the way, and also when sailing used the 150% Genoa, instead of the working jib! The spints held, and he got a new mast.

 

[DKennaC25]

I drilled all mine out and replaced with stainless steel 1/4 bolts.
I filled the slit with 4200 and put big blobs of 4200 at each bolt hole.

Rubber fit fine when reinstalled.