Replacement Chain Plate and Support Rod - '84 H31

Mar 20, 2011
623
Hunter 31_83-87 New Orleans
I have placed in the owner mods, the steps taken to replace the chain plate and support rods for both port and starboard after losing the port side due to metal failure resulting in the loss of the mast. also important to note with my insurance policy, it did not cover the failure due to "rust, corrosion and fatigue". Suggest owners check their insurance policies. In my case I was able to find a replacement mast from a hurricane damaged boat saving me quite a bit of money but the overall replacement of standing, running rigging and repairs to chain plates was extensive. any particular questions, please send me a IM.
 
Apr 22, 2011
865
Hunter 27 Pecan Grove, Oriental, NC
Nice job with your mod posting. Looks like the support rod broke where it was screwed into the backing plate's acorn nut. Was the piece of the lower part of the rod still in the stainless acorn nut?
 
Mar 20, 2011
623
Hunter 31_83-87 New Orleans
Yes, the lower piece of the rid remained in the castle nut. The failure was not from the rod pulling thru the mild steel plate but appears to be more as a failure between dissimilar metals over time.
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
It is scary that the rig depends on a piece of mild steel angle iron that isn't even galvanized and cannot be viewed for inspection.:eek:
 
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Mar 20, 2011
623
Hunter 31_83-87 New Orleans
Agree. This is a poor design at best especially since you can’t see any deterioration in the metals, and they used a painted mild steel for a plate with no inspection port provided. I guess Hunter didn’t think these boats would last as long as they have.
 
Jan 22, 2008
1,654
Hunter 34 Alameda CA
Thanks for posting your article. Do you still have the piece(s) of the rod still in the castle nut? If you could take a very close picture of the actual fracture that could be useful.

Two dissimilar metals can coexist if not bathed in an electrolyte. Was the area prone to water saturation? But the failing metal would be the soft iron (the least noble). I'm curious to look at the fracture for signs of flexing (ductile fracture) or from a concentration of stress in the depth of the threads (more like a brittle break). Just trying to learn and anticipate what is in store for my boat.

Was the old castle nut free to turn (at least originally)? I thought that might have been how the entire rod is tensioned or pulled down snug to the deck.
 
Mar 20, 2011
623
Hunter 31_83-87 New Orleans
Alan - no longer have the piece parts. Attached pic is the rod where it broke in the castle nut. It appears it snapped or broke lose from the piece still in the nut. it was at the surface of the iron where it screws into the nut. The nut is threaded and welded in place and does not turn. The rod screws from the deck downwards into the nut that is welded into place. Also attached a pic of the angle iron where it snapped (see circular ring in the rusted area). It does not appear to be a flex fracture because the nut/rod did not pull thru the rusted angle iron.





The pic indicates a brittle break. As far as saturated in water, I have owned the boat for the past 7 years and have kept the deck chain plates caulked/sealed. I can't speak for the other 27 years of the boats life. I can only assume from the surface rust in the small inspection area provided by Hunter, the previous owners did not attend to this as carefully as they should have.

I found the chain plate pics below on the forum from a very old post on a H34 that was damaged in the Caribbean and this is what the owner did to fix. this gave me the ideas needed before cutting into hull liner. hope this helps. IM if you have any more questions.


This is something I would add to and move up on the maintenance list especially if you intend to keep the H31's and H34's. If you have access to a machine shop to fabricate the angle and new rods the repairs can be done by an individual instead of a yard once the mast is down. I was surprised how much the replacement rig and associated items cost. I had too much invested into my boat at the time of the failure and wasn't interested in any other boat except the H31. This is the perfect size boat for me and therefore I decided to go ahead with the repairs instead of scrapping the boat. also it didn't help matters with the insurance denying the claim. Check your policies. Mine is with progressive and clearly states coverage does not apply to wear, tear, corrosion and fatigue. Jerry.
 

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Jan 22, 2008
1,654
Hunter 34 Alameda CA
Thanks Jerry additional information. Good stuff on your post but really sorry you had to go through all of this. At least no one was hurt when the mast went down. Its good to know that the repair is possible without cutting through the hull from the outside.

I was trying to figure out a way to retain the rod in the boat if the same thing happened to someone else with these designs. Even if there was a clamped on split ring right under the deck that could catch before the mast would tip very much. I'm also worried that if the forestay ever broke the entire thing would fall, whereas in the other directions there is built in redundancy.

My friend had a similar problem with his insurance company. He had a laminated spruce mast that failed and his claim was denied. Seems there was an exclusion for failure of plywood. Since his mast was multiple pieces glued together, it was deemed plywood and no coverage. His recourse was to discover the company did not own their domain name so he bought it and wrote the entire story up and posted it. Anytime someone would search under that company name it would come up to that. They tried to sue him but it was all true. Then they tried to buy it from him but just to be stubborn he never sold the name to them. Pretty funny.

Allan
 
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Mar 20, 2011
623
Hunter 31_83-87 New Orleans
Allan - doubt a split ring would work. If rig is under load/sail, then it will pull thru the deck below pics of bent support rod and deck damage when it pulled from port side and went over starboard side. Mast hit the life line with such force it bent the stanchion and the lifeline wire acted like a knife and cut the mast where it hit the lifeline. The mast was actually dangling at a 90 degree angle from the lifelines. we were lucky one of the spreaders didn't poke a hole in the boat.
 

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Sep 4, 2007
764
Hunter 33.5 Elbow, Saskatchwen, Can.
Jerry could you send me the link to read your mod? I've looked in Hunter mods 31 83-87 and can't find it. All I can see is there are 27 mods. Maybe someone could point me in the right direction.
 

Manly

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Jan 3, 2018
47
Hunter 31 St. Petersburg
Hello jmce1587, I'm sorry you had to go through this ordeal! What a nightmare. And a very poor design by Hunter. I've never liked that all the side stays go to that one location instead of being spread out to multiple like it is on many sailboats.

I own a 1984 H31 so this does hit close to home. Reading your story makes me not hesitant even climb my mast (my profile pictures is myself at the top).

I do have a few questions:

1) In this picture you posted, the angle has rusted away. Would you have been able to see this in advance if you had drilled an access hole underneath the rod? I'm thinking I should drill an access hole there on both sides and look up from underneath. Would you recommend that?

Angle Eaten Through.jpg

2) Did the angles come out easily, or were they a bear to get out? Were they bonded in?
3) For the new angles, did you bond them in place, or just let the tension of the rod hold them in place?
4) From your pictures, it seems like you used a slightly different design for the port and starboard side. It looks like you used a 30"x2"x3/4" thick flat plate for the port side, whereas you used an angle for the starboard side. What was the reasoning behind this?

I'll probably think of more questions later. Thanks!
 
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Mar 20, 2011
623
Hunter 31_83-87 New Orleans
Hi Manly - thanks for the note. I suggest all older hull Hunter owners check their insurance policies. Mine is with Progressive and they denied the claim based on "rust, wear/tear and corrosion". Not sure if other insurers have these same exclusions.

for question 1 - the area that Hunter provides on our boat for a visual inspection is not much, it measures 3" long at best and if yours is in the state of mine, you will likely see visual surface rust. You can drill an inspection hole/cover below the area where the rod comes in. I have now added these to both port and starboard for future inspection. Would this have helped me, probably not. After the failure, we inserted a camera in the inspection port and it did indicate rust on the angle iron. My failure was the rod broke where it is inserted into the plate. It did not pull thru the plate. the carbon steel was intact albeit not by much (see pic of failure point). Mine was more of a metal fatigue on the rod/castle nut connection.

for question 2 - yes it did come out easily once we cut the opening to remove. for the plate that didn't break (starboard side) we cut the rod above the chain plate opening in the cabin. that made it easy to remove. (see pic of inspection port and opening we cut into the liner.)

For question 3 - we used 5200 to hold the new stainless steel angle iron in place. We wanted something to remain in place when tightening the rods. In my original post, you can see from the repair pics from the H34 that Hunter originally used a bolt/nut to hold the angle iron in place before inserting the rods and tightening down (see pic of 4 pics in one - titled chainplate 1). Since the boat is already 34 years old and the fact that we went with similar metals (SS for angle/rod in lieu of original design of CS and SS rod), we elected to go with the 5200 to hold it in place. I believe the new materials will outlast the boat.

For question 4 - we used the same SS angle iron on both sides, 30" long a 4" x 1/4" thick (see pics of measurements and pic of new SS angle iron.
If you have an additional questions, please IM me and I will send you my mobile number. good luck with yours.
Jerry
 

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Artey1

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Jul 18, 2019
165
Hunter 34 Oklahoma
Jmce1587, I'm going through something similar here on my H34. Although luckily my rig has not come down as a result of failure. I was rebedding my chainplates and cannot restart the threaded rod into the plate. Upon further inspection with my finger in the hole, there appears to be no nut on the other side of it, leading me to believe the nut has rusted off. The plate has visible surface rust but honestly doesn't look that bad. My boat doesn't have any bolts holding the angle iron up. I'm waiting on an endoscope to arrive so I can inspect my plates and try to "see" the nut with the endoscope camera. It would help to know before drilling a large 3" or 4" access hole. Can you tell me which orientation the vertical part of the original angle iron is to the hull? Is it against the hull or inboard of the hull?

edit: Scratch that, obviously it can't be lying against the hull after I think about it more. I'm just wondering if I can get my hand in behind it at all to hold the nut, or a new nut and secure my tie rod if the plate appears to still be in good condition. Of course if it isn't, I'll be welding a nut to the new angle or plate that I use
 
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Mar 20, 2011
623
Hunter 31_83-87 New Orleans
Evan, please keep us up to date after our discussion and addl photos And please document your fix for the rest of us with older hunters. Thanks Jerry
 

Artey1

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Jul 18, 2019
165
Hunter 34 Oklahoma
I've updated my thread on the "Big Boats" forum here. I believe that I will not need to replace my plates after inspection with camera on both top and bottom of the port and starboard plates. It also facilitated a way for me to add a new nut which is what my main issue was on my port side. Cheers to Captain Jerry for all of his help and generosity. I will be inspecting my plates with this camera method annually now.