Hunter 216 Chain Plate

[Glenn8732]

Has anyone done any modification or stiffening of chain plate on the Hunter 216. I was out in some extremely strong winds on the weekend, so much that I sailed on the head sail alone. I noticed that the chain plates were moving a tiny amount off the deck, flexing in the gusts. There was enough movement that water spray was getting through the chain plates and dripping into the cabin.

My plan is to take off the chain-plate and stiffen the underside of the deck, and possibly stiffen the chain plate itself so it transfers the load more efficiently to the tangs down the hull.

Thoughts.

 

[sail sfbay]

This thread about a Hunter 216 chain plate and article entitled "Rebedding the chainplates" might be helpful:

Hunter 216 deck crack at chain plate

First time on the forum and glad to have the resource. I run a youth sailing program at my yacht club in San Diego. A 2005 H216 was recently donated to us and it's a perfect boat for us. As I was cleaning it up I discovered a crack on the starboard side deck running transverse through the aft...

forums.sailboatowners.com

Rebed chainplates

www.threefools.org

 

[Hunter216]

Has anyone done any modification or stiffening of chain plate on the Hunter 216. I was out in some extremely strong winds on the weekend, so much that I sailed on the head sail alone. I noticed that the chain plates were moving a tiny amount off the deck, flexing in the gusts. There was enough movement that water spray was getting through the chain plates and dripping into the cabin.

My plan is to take off the chain-plate and stiffen the underside of the deck, and possibly stiffen the chain plate itself so it transfers the load more efficiently to the tangs down the hull.

Thoughts.

Hard to say how to improve as it’s hard to say where the movement is. I can’t see that stainless bracket flexing much at the bend but who knows. Maybe have some little angles welded on to stiffen it.

I guess I would start with removing the chain plate to see if any of the holes through the Luran and/or inner FRP layer show any signs of “enlargement” which would indicate prolonged movement. If the holes look normal I would just rebed and sail on.

I have noticed that if I’m out in “brisk” conditions (main reefed and jib furled) which is pushing the design envelope there is some flex in the hull. I’m by myself when I have done that so it would likely be even more pronounced if I had a few adults aboard.

Please keep us updated on how you tackle this.

 

[Glenn8732]

Repair complete. I was shocked at my discovery.
Original construction, ACP deck, 1" woodblock approximately 4"x8" in size, and an inner layer of FRP.
I found, wood completely mush and saturated. THE inner FRP layer cracked and failed, so no chainplate support from the deck probably during the high wind sailing. All the load was being held by the two screws in the hull, which also were bent from the loading.

For repair, I replaced the woodblock, sanded the FRP 4" back, added 5 layers of West epoxy and glass cloth, drilled out for bolts, and bedded the bolts with 4200. I also added 3 layers of epoxy and cloth on the inner hull, redrilled those holes, and added new bolts.

Picture 1. The area after chainplate removal
Picture 2. After removing FRP, and the wet wood.
Picture 3. New wood, ready for epoxy
Picture 4, FRP repair completed, chain plate installed.

 

[Hunter216]

Wow!

It’s a good thing you caught that before you had a mast failure. Probably would have left a mark.

If you don’t mind I would appreciate some further detail so I’m working on formulating a few questions as you have motivated me to check mine.

 

[Glenn8732]

If you are seeing brownish stains in the carpet around the chainplates, that is a clear sign that the wood is wet and needs replacing. As far as repair, it was not difficult.

 

[Hunter216]

Here is my general thinking on how I will “inspect” mine. I’m not sure I want to disturb the bolts that go through the sides of the hull so I would remove 3 nuts and attempt to lift the double hoop component that the shrouds attach to. This would then let me remove the inner L shaped component by pulling it off the two hull bolts. Assuming that goes well and there is no staining I would perhaps drill into the wood to confirm it’s solid. If it isn’t solid proceed with demo and rebuild, if OK bed with 4200 or some other suitable material and done.

Questions in no particular order

1) How challenging was it to remove the “carpet” headliner without destroying it?

2) When you pulled the outer double hoop component were you able to see much inside? I was thinking I might be able to probe the wood insert to test integrity.

3) In the dimensions of the wood insert you mentioned a 1” thickness. Was the wood completely flush against the Luran layer or was there some foam between those layers?

4) How did you reseal the two holes through the side of the hull?

 

[Jackdaw]

I want to go strangle the person that thought wood (untreated no less) was a good idea as a structural part of a modern sailboat.

As Steve Jobs said ‘ kill everyone involved. And their children. ‘

 

[Glenn8732]

Here is my general thinking on how I will “inspect” mine. I’m not sure I want to disturb the bolts that go through the sides of the hull so I would remove 3 nuts and attempt to lift the double hoop component that the shrouds attach to. This would then let me remove the inner L shaped component by pulling it off the two hull bolts. Assuming that goes well and there is no staining I would perhaps drill into the wood to confirm it’s solid. If it isn’t solid proceed with demo and rebuild, if OK bed with 4200 or some other suitable material and done.

Questions in no particular order

1) How challenging was it to remove the “carpet” headliner without destroying it?
I cut the headliner carpet with a knife diagonally from the corners, I have not glued it back yet, and there will be visible seams but I think it will look ok. if not might just build a cover plate

2) When you pulled the outer double hoop component were you able to see much inside? I was thinking I might be able to probe the wood insert to test integrity.

I would suggest removing the nuts from side hull bolts as well and removing the chain plate, you will be able to tell if the wood is wet through the holes, You can take the chainplate off without removing the bolts, once the nuts are off the bolts can stay in place and the chainplate will come off. With the chainplate off you should be able to see into the holes and poke the wood.



3) In the dimensions of the wood insert, you mentioned a 1” thickness. Was the wood completely flush against the Luran layer or was there some foam between those layers?

There was no foam, all wood between the Luran and the FRP inner layer. I am estimating 1" of wood it may have been less, literally fibrous mush that was wood. Once I had the new wood (3/4 plywood) in place I put the chainplate back on the two hull bolts and there was 1/4 gap between the wood and chainplate, so hence my 5 layers of glass cloth, and a little sanding and the chainplate fit into the exact spot to match the hull bolts. I then redrilled my holes through the wood and FRP for the double hoop u bolt assembly. I oversized the holes and painted epoxy into the holes so the wood will last longer.

4) How did you reseal the two holes through the side of the hull?
I reused these holes. I pulled back the inner hull liner and put 3 layers of epoxy and glass cloth over the holes on the inside of the hull. With the chainplate off the hull liner is not glued down and can be pulled back easily. Once dry I let the hull liner back, drilled through the chainplate and FRP from the inside. They lined up exactly with the original holes. I used 4200 to bed the u-bolt hoops and the hull bolts, so there is a good seal at all hull and deck penetrations.

 

[Hunter216]

Glenn
Thanks for the detailed answers. Are you still thinking of modifying the chainplates?

 

[Hunter216]

I want to go strangle the person that thought wood (untreated no less) was a good idea as a structural part of a modern sailboat.

As Steve Jobs said ‘ kill everyone involved. And their children. ‘

Don’t be shy, tell me how you really feel about this

 

[Crazy Dave Condon]

@Glenn8732

Could you under boat information under owner modifications put in a report on the repairs to include photos please. I would really appreciate it as it will help others.

@Jackdaw

You have no idea how I went ballastic when Hunter decided to let JY build the boats out of ACP to include the President of sales and plant and with Warren Luhrs. Later, they said they wished they would have listened to me buildig out of fiberglass. Duh! I agree with you on your statement.

 

[Glenn8732]

Glenn
Thanks for the detailed answers. Are you still thinking of modifying the chainplates?

No I don't plan to modify the plates. They will flex if failure of one of the deck components happens, but the hull bolts will hold until a repair can be done.