Mast Conduit Rivets

Ron Hill · September 30, 2012, 12:14:26 PM

We've had two owners complain that the rivets that hold the wire conduit inside the mast are letting go!

I'm interested in this problem and wondering why the rivets are letting go? :
1. Were the rivets not installed properly?
2. Are the rivets on an unpainted mast eroding from salt water? The mast was anodized, but not the rivets.
3. Are the rivets on the painted mast eroding from the inside?

Pop rivets are hollow after being installed. Should people take a bit of caulk and fill that hole to stop any corrosion?

Just interested if we all have a potential problem or not?? I'll be interested in the posts !!

Dave Spencer · September 30, 2012, 06:01:15 PM

Ron,
I inspected my mast today with it lying on horses. The rivets look fine, they simply pulled out of the conduit. In every case where I could see or feel the conduit by a rivet, there was a ragged hole in the conduit. Being in the Great White North, the mast comes down almost every year and I store the mast with the groove down so it doesn't fill with water and freeze. This means the conduit is hanging from the rivets since it is secured to the forward edge of the mast. I suspect there is a surprising amount of weight in the conduit (pvc?) and the wires which is fine when the rivets are in shear when the mast is up, but inadequate in tension when the conduit is hanging from the rivets.

Any other thoughts?

Fred Koehlmann · September 30, 2012, 06:14:45 PM

I'd be curious if this is an issue with predominantly northern boats? Considering the length of the mast and that fact that the mast and conduit are different materials, the difference in expansion and contraction due to temperature change could gradually loosen the rivets hold.

Ron Hill · October 01, 2012, 02:26:42 PM

Dave : Thanks for you reply and your analysis has some good thoughts. There is some weight involved in 50+ feet of conduit and wires inside.

You didn't mention if you have a painted or anodized mast. The only reason I mentioned that is corrosion, which you ruled out because the outside of the rivets are intact. Maybe mast storage on it's side (PVC) is a solution??

It will be interesting what Paul has to say, as his boat in on the Gulf of Mexico.

If any other owners C34 or C36 has had (having) that problem, please sign on and let us know.

Ken Juul · October 02, 2012, 05:02:24 AM

I've got something going on with mine. My initial thoughts are that it is the Radar Cable that has lost it's tiedown, I noticed it last time on the boat and haven't investigated yet.

Dave Spencer · October 02, 2012, 07:33:59 AM

Ron,
My mast is painted. There is zero evidence of any corrosion anywhere on the mast. I failed to take pictures last weekend but will try to get some this weekend. The problem does not lend itself well to photography. Don Casey's "This Old Boat" has illustrations on how to address this but I fear they may be slightly oversimplified. I'm fortunate to have the mast down to do this work and will figure it out before we launch again next spring. I'd love to figure out some kind of a compression clamp that would grab the conduit inside the mast as I tighten a flush screw on the outside of the mast.

Ron Hill · October 02, 2012, 08:30:09 AM

Dave : Thanks for your reply. I'm going to guess that your boat is mostly in fresh water.
I'd be careful with flush screws (atleast blunt the tips) as they could rub against the wire's insulation.

You might want to try my suggestion on the 2x8 to hold the conduit in place while you reattach it.

We await your pictures.

Dave Spencer · October 02, 2012, 06:16:25 PM

Ron,
I agree that flush screws piercing the conduit would not be wise since they would likely be weaker than rivets and would possibly damage the wiring inside. I was thinking of trying to come up with some kind of an expandable clamp or restraint that could fit in the hole and grab the conduit as a screw is tightened from outside. Think about the butterfly brackets (I can't think of their real name) that can be inserted into a hole in drywall and expand when tightened to hold pictures etc. Not exactly that but along those lines. I like the 2x8 idea but it would only work for the bottom few rivets (and I guess the top few if I pull the mast cap off)

Ted Pounds · October 03, 2012, 08:32:40 AM

Anyone tried calling Catalina about this? I'm guessing that, if this is an issue on multiple boats, Frank or Gerry would want to hear about it. Also they can tell you how they did the rivet job in the first place. Just a thought...

Ron Hill · October 03, 2012, 01:27:28 PM

Ted : You are absolutely correct, but I am waiting to talk with Gerry when we have a bit more information.

pablosgirl · October 03, 2012, 02:10:23 PM

Hi Ron,

Our boat was originally an up north salt water boat, In the old owner data base, the boat is still listed as "hull 551, Golden Eye II, Bob Hackell, Northfolk, VA". The boat was purchaced by my PO in ~2003 and trucked to Texas. It was damaged in hurricane Ike and that is when we bought her.

The mast is painted and there are no signs of corrosion around the rivets. The rivet heads are also painted, so I would assume that the conduit was added to the mast before it was painted. Also the rivets appear still to have the tension plug in the end. At least the ones at deck level. There is one rivet that is next to one of the halyard exit/entry ports in the mast. I plan to remove the entry/exit plate and push/hold the conduit in place while attempting to fasten a new rivet in the original hole. But I fear that the hole in the PVC has wallowed out and the rivet will not grab the conduit. I don't plan to pull the boat or the mast for that matter until next summer to renew the bottom paint and possiably re-paint the mast. I used a coat hanger while we were out on the boat last week, and it seemed to quiet down the slapping. I did not eliminate it. So I must have other loose rivets at the top of the mast as well.

Paul

Phil Spicer · October 03, 2012, 02:19:39 PM

Ron, any chance you could ask Gerry about this rivet issue while you are at the boat show this weekend? I would ask, but the doctor won't let my wife ride that far. Will miss the show this year. This has been a yearly trip since we retired. Always a wonderful weekend.

Ron Hill · October 03, 2012, 05:27:48 PM

Phil : I will see Gerry on Friday and mention it to him.

I'll report what he says.

lazybone · October 03, 2012, 07:03:17 PM

Years ago, so I do not remember exactly where, I read a DIY articale about installing a conduit in a mast.
The author suggest drilling two holes in the mast side by side. One hole is for the rivet and the other for inserting a piece of stiff wire bent into sort of a "J" shape. The bent part of the wire used to pull the conduit tight to the inside face so the the rivet will take.

Not sure if that makes sense. If it doesn't I will have another glass of wine and try again.

Phil Spicer · October 05, 2012, 08:40:07 AM

Thanks Ron. I appreciate your efforts. Hope to hear something soon.

Lazybone: I think I read the same articale. If you use the same rivet hole and use a larger rivet , the same hole in the conduit could be used. That may overcome the problem of the conduit hole being enlarged when the old rivet pulled out.

Just my thoughts