Typhoon chainplates

[Ben Miller]

I'm in the midst of a long-term project to check the health of all the deck-mounted hardware on my Typhoon. Yesterday I decided to investigate the shroud chainplates, so I stuck my phone back under them and snapped this picture.

Everything looks healthy under there, with no sign of leakage or deformation, so I'm not worried about it. Still, I thought it was interesting that there doesn't appear to be any significant backing of these bolts, despite what the diagram in the CD25 manual shows.

[mgphl52]

In my opinion, those look like they have been replaced. Yes, you really do want some better backing than just those washers!

[JD-MDR]

Looks like the drawing shows two steel backing plates in between the liners. but I don't see the straps or rebars going down the hull. Like mine has. I attached my modified g-10 plates, the deck padeye bolts are in the photo yet but I have 5/16' bolts and fender washers now up against the backing plate

[Ben Miller]

In my opinion, those look like they have been replaced. Yes, you really do want some better backing than just those washers!

Could be! It just looks so clean in there, it's hard to imagine that there was a factory backing plate that got removed. Any other Typhoon owners have personal experience with their chainplates?

What's the group suggestion for a quick solution to this? A sheet of G-10 epoxied in there? Access is really tight, so I can't do anything elaborate. Plus, I'd like to get her out on the water soon!

[Ben Miller]

Looks like the drawing shows two steel backing plates in between the liners. but I don't see the straps or rebars going down the hull. Like mine has.

Based on the drawings in the manual it looks like the smaller Cape Dories had simpler chainplate reinforcements than the larger ones.

[mgphl52]

Based on the drawings in the manual it looks like the smaller Cape Dories had simpler chainplate reinforcements than the larger ones.

The manual drawings show the steel "laminated" with the cabin liner. I don't recall my last Ty having it that way, but that was a bunch of years ago.
Just to be safe, especially from the laminated steel corroding away, I would add something as a backing plate, preferably 1 piece with two holes.

[Ben Miller]

I did some digging in the forum archives. Here's one report of a situation like mine. Here's another.

It sounds like this might be pretty normal. Maybe there's a metal backing plate sandwiched in there somewhere (contrary to the diagram) but it sounds like often, if not always, there wasn't one on the bottom of the sandwich. I'm inclined to leave things as they are, at least for the time being. Maybe next year I'll upgrade the whole thing with some new bronze chainplates and some real backing.

I also found an alarming thread about chainplate bolt corrosion and failure, so I will definitely be pulling the bolts and checking them before launching.

[Steve Laume]

I have to take exception to the general advise being given on this matter.

What you have looks to be original and in great condition. If you look at the drawing, you will see that there is one layer of glass, that is not labeled, covering the steel backing plate. You are not going to see a backing plate but rather a layer of glass that covers it, that ties it into the liner. Everything is through bolted and there is only a thin layer of glass over the backing plate so there is no need for anything more than those washers, under the nuts. What you want to be looking for is any signs of rust or deformation around the bolts. What you have, looks great, from the picture you supplied. Adding another backing plate on top of the backing plate is not going to do you any good. If anything it will just hide any problems that might develop, later in the life of the boat.

The only thing I would recommend is that you re bed the chain plates so no problems develop in the future, Steve.

[Jeff D]

I have a 1984 Ty and the underside of my chainplates looked the same. There is some mention that the later CD used Al backing plates. When I last rebedded, I replaced the bolts with some known quality bolts from McMaster Carr and added a 6" x 2" x 0.25" SS backing plate. I would be more concerned with the state of the bolts than the backing.

[Ben Miller]

Thanks everyone. I'm going to proceed with my plan: Pull the bolts to make sure they're OK and replace if they're not. Rebed everything to keep them nice and dry. Sleep peacefully.

[Ben Miller]

Update: I pulled the chainplates. It's a real pain reaching in through those little holes, but a deep socket and an extension made it doable. The bolts that came out looked great. The port side felt a little wet, so there may have been some minor leaking going on there. I cleaned everything off and re-bedded them with butyl tape.

I'm glad to know that the bolts are in good shape. It's really not that hard to do, so if there are any Ty owners out there who are uncertain as to the condition of their chainplate bolts, I'd recommend this. And I love working with butyl tape. It's so much cleaner than the goopier sealants.

[mgphl52]

And I love working with butyl tape. It's so much cleaner than the goopier sealants.

It will last a *lot* longer too!

[Sailhmlri]

Backing plates

[mgphl52]

Well done!

[Sea Hunt Video]

Very well done That is piece of mind.

On a sour note, you have managed to add to my growing "to do" list on S/V Bali Ha'i.