H34 chainplate anchors

[ScottFreeRick]

Winter is here in Nova Scotia, but so far has not prevented us from getting some work done on the boat. I have completed the compression post replacement, many thanks to Brian who provided drawings and insight into this job. Prior to launch in the spring, I want to rebed the mast base and the chainplates. As I looked at the forum, I have become convinced that now is the time to check out the angle iron anchors for the chainplates. In the event there is corrosion that requires attention, I would like to get to it sooner than later.

I thought that I saw where someone had installed an round inspection panel directly below the rod, to give access to the area. However, I have spent the afternoon searching and cannot seem to locate the post. I have a couple of questions for the group.

First, is there someone who has installed such an inspection plate? And if so, how long has it been there and is there any signs of cracking / stress on the area?

Second, for those who did replace the angle, did you glass over the opening or leave it?

 

[Capt Robbie]

I have a 1983 hunter 34 and Became a little concerned After reading other post about the potential chain plate issues with hunters from production years 1983 - early 1990’s. That had chain plate rods that were threaded into a steel angle iron with a bolt that is welded onto the bottom of the plate “ referred to in the brochure as the chain plate anchor “ Unfortunately for some reason hunter used steel as the chain plate anchor and created a potential dangerous condition. using steel instead of stainless steel as the chain plate anchor material is not a great choice. As everyone knows steel is not a friendly material to use in a marine environment not to mention that they also used two dissimilar metals which also has potential issues from electrolysis. The thread basically explained that the chain plate anchor corrosion became so severe that the rods pulled thru the deck and in some cases resulted in a complete mast failure.

I was always under the impression that the chain plates anchor were made of stainless steel, however they are not! Now to make this even more concerning, is that there is no way to inspect the steel chain plate anchors because they are behind and part of the cabin liner grid system. This is a horrible design issue because if you inspect your standing rigging and all appears to be in good condition, the chain plate anchors could potentially be a corroded time bomb just one puff of wind away from a disaster with the potential of serious injury.

I strongly recommend that everyone inspect their chain plate anchors before going back out on the water. I installed 4 inch inspection port on my cabin liner just aft of the chain plate anchor rod. For me I found this to be my best option. However if you own a endoscope camera that may be a less aggressive option.

After cutting in the inspection plate, my chain plate anchors were to my surprise in really good condition. Very little rust for being 39 years old. I’m planning to clean them and coating them when the weather is better in the spring.

Again I strongly recommend that anyone that have hunters with this design do this mod to inspect the chain plates. I believe the models that have this type of chain plate anchors are
Hunter 31, 34, 37, 40, and all of the legends, I believe 1983 thru the early 1990 models.
I would like to know from anyone that has this corrosion issue of the anchor plates if they had any leaks from where the deck fittings connect to the rods.

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[Capt Robbie]

my chain plate anchors were all good, however if you plan to cut in the inspection plates try to go as low to the molded fiberglass strut as possible so that you will achieve the maximum visibility to the bolts and rods. If I were to have gone a little lower on my cut out it would have been a lot better. I was afraid that I would cut into the hull originally, however there is a lot more space then what I remembered when the boat was built.
As far as if anyone has fiberglassed the cut out, I don’t think so. If I had to cover the cut outs to make repairs I was planning to use a piece of star board or oak and screw it to the face of the opening.

hope this helps

 

[ScottFreeRick]

Thank you. That is great information, and the pictures provide a good visualization. I am curious, how long has it been since you installed the inspection ports and have you noticed any indications of the surrounding grid being stressed from the cut out? I am hoping to get to the boat again within the week and would like to install similar ports on both sides to inspect the angle iron. I have been soaking the threads regularly in order to remove the chainplates for rebedding. Is the welded nut mild steel?

You mentioned that you wished you had made the cut out lower. Would this not have made it harder to inspect the area?

 

[Capt Robbie]

I just installed them about five weeks ago, and the grid system should not be affected at all. Not sure if you are aware that hunter constructed these boats with a modular prefabricated cabin and just the molded fiberglass cross beams are bonded the hull.
Where I cut is technically part of the cabin liner.

As I suggested I would make the cut outs a few inches lower, because I believe that if I were to have gone a little lower then you would be able to slide an inspection mirror under the chain plate anchor much easier. Hopefully when you make the cut out your chain plate anchors will be installed with the angle iron facing the hull and you will not even need a mirror to inspect. Mine were installed facing the wrong direction so I can’t see the bolts unless I use a mirror. you have a 50/50 chance.
Try to use round inspection plates rather than square so that the gel cote has less of a chance spider cracking. Suggestions for getting the rods freed up, put some radiator antifreeze coolant on the threads, the antifreeze has chemicals in it that breaks down rust and corrosion. I’ve used this on lots of rusted bolts and works amazing, just have to let it penetrate for a few days. My mechanic taught me this years ago and it works like a champ.

good luck

 

[ScottFreeRick]

Thanks for the advice on the anti-freeze. I will give it a try. The weather mid week looks warmer, so I hope to get there and cut the holes, and do the inspection. Everything I have read, I thought that the angle iron was oriented so the vertical face was against the liner. It appears the angle is 4" so I will try to cut lower for a good look.

 

[ScottFreeRick]

Got to the boat this afternoon. After digging out the snow in the cockpit, I was able to get into the cabin. Temperature not too bad after running the diesel heater for a while. I used a hole saw to cut a 4" hole in the vertical face of the liner. From there, it was a simple task to inspect the angle, gussets, and welded nut on each side. Other than some minor rust on the surface, the anchor plates are in good shape. It will give some peace of mind when we are out on the water. Next will be to remove the chainplates and rebed them, once the weather warms up. Also plan to spray the anchors with rust check.

 

[ScottFreeRick]

Beautiful day here, 10C plus, very windy. Thanks to the advice from Capt Robbie, the chainplates broke free easily. Removed both sides and brought them home to clean and prep for reinstallation. Good news is the threads on the chainplates and anchors are in great shape!