356 Keel Joint

[Knotallthere]

Good day,

We acquired our 2002 356 in Sept 2015 and as you can see from the photos the keel joint needs to be faired. I have been talking to some old salts around our yard one of which did a lot of warranty work for Hunter for this vintage boat and said not to re-torque the keel bolts. What say you? What method / products do you recommend?

Any and all input would be greatly appreciated!

 

[chuckwayne]

re-torque the keel bolts and then refair. The fairing compound is very brittle and this kind of cracking is common. You can also use 4200 caulk to fair the cracked area - it will flex a little and not crack from keel loading

 

[Knotallthere]

Thanks Chuckwayne. Do you happen to know the torque specs for the shoal keel bolts for the 356? Are there any precautions recommended before tightening? Is temperature a factor? Do you recommend using any lubricants on the treads etc.?

 

[Terry Cox]

Something does not look right from the photos you provided. It appears to me from them that the keel stub joint has been compromised and that some amount of separation of the joint has occurred. Applying 3M4200 to the joint from the outside and re-torquing the keel bolts is at best a temporary fix. To make it a permanent repair a yard needs to lift the boat off of the keel, clean the joint at both surfaces then re-bed with 3M5200 or equivalent sealant.

Keel stub joint cracking is not normal, IMHO. Usually the crack occurs when the keel strikes an object that forces the joint to open or dislodge. Our 1991 P42 with an 8,000 pound lead keel has zero cracks after thousands of cruising miles in all kinds of weather conditions.

Our yard recommended 4200 for above the waterline repairs and 5200 below because you want a stronger bond than 4200 provides. Once the keel has been re-bed, finish with whatever material the yard recommends. Some suggest two coats of hard bottom paint followed by an ablative. Some also say an epoxy barrier coat. Owner's choice.

 

[Bob 04 H260]

I looked at the pictures. I don't think those cracks are in the fairing compound in the keel joint. There should be lead right where those cracks are I believe. I would sand some of the paint off and see. Is it possible it is just cracks in the paint ?

At the ends of the keel the joint is right against the hull, then about 6" in there is a fibreglass keel stub that comes down about a foot, that's the sump the big keel bolts are in the bilge. I would think if you had a problem with the keel joint you would see cracks along there. So the keel/hull joint is like mortise/tenon joint.

Probably a good idea to re-torque those keel bolts anyways. I don't have the number handy, if you search this site they have been posted a few times. The big bolts are like 300 ft lbs. so you will need a torque multiplayer for that, plus a big, deep socket etc. I have that equipment, it's expensive. Try to borrow it if you can. If you can wait I'm sure we can work something out.

So try cleaning off the paint to see what is going on there with the lead, let us know.
Bob

 

[Patrik]

Hi,
I have the same model and problem. It's called Hunter Smile and if you search for that in the forum you will find more information. I have filled it with soft sikaflex (recommendation from a boatmanufacturer) and not re-tourched the keekbolts as they were already ok.
Good luck

Patrik

 

[JamesG161]

Something does not look right from the photos you provided. It appears to me from them that the keel stub joint has been compromised and that some amount of separation of the joint has occurred. Applying 3M4200 to the joint from the outside and re-torquing the keel bolts is at best a temporary fix. To make it a permanent repair a yard needs to lift the boat off of the keel, clean the joint at both surfaces then re-bed with 3M5200 or equivalent sealant.

Keel stub joint cracking is not normal, IMHO. Usually the crack occurs when the keel strikes an object that forces the joint to open or dislodge. Our 1991 P42 with an 8,000 pound lead keel has zero cracks after thousands of cruising miles in all kinds of weather conditions.

I agree. It appears that it hit hard, not sand. It also appear to have driven you keel aft. that would mean more than just dislodged.
But then this is just an limited observation... Hoping keel bolts are unaffected.
Jim...

 

[Knotallthere]

Thanks everyone for replying, the photos were taken from my crackberry and are not of the best quality. Aside from the crack there is zero evidence of a grounding in that there are not marks anywhere on the keel, no cracks and the keel bolts have zero cracks around them or any signs of movement etc. At this stage I'm going to sand the area by hand as suggested by Bob and see if the crack is in the fairing compound, or stub. I will post some pictures once I sand it down. I have a large torque wrench and deep socket's, I just need to check how many foot pounds its rated for. Thanks Bob for suggesting that I could possibly borrow yours.

Best regards,

 

[Bob 04 H260]

There is a long thread here on tightening the keel bolts, the torque values are posted. The threads should not be lubricated.
http://forums.sailboatowners.com/in...ghten-keel-bolts-if-ever.158254/#post-1078293
Bob

 

[chuckwayne]

the torque specs are:
3/4" bolts - 132 ft-lbs
1" bolts - 325 ft-lbs

 

[Bob 04 H260]

http://www.marlow-hunter.com/export/Model-Information/356 Hunter ----/35014003_1_metric_C2000.pdf

Here is a PDF of the keel on a H356. The stub extends down about 8" into the lead keel and stops a few inches short of each end. The lead goes right up to the hull at each end.
There does not appear to be a seam or joint in the keel where the cracks are in the photograph.
Bob

 

[RoyS]

The drawing supplied by Bob 04 provides some clues to your problem. First you will note that there was a revision made to that part of the keel attachment in 2002. See revision B note on the top right of that drawing. This revision added a new attachment bolt to the very area that you are studying. I suspect that this was a weak point and you are probably not alone with this problem. You will most likely find that your boat was just ahead of this improvement. Inspection of the bilge will determine if your boat has this additional bolt. I suggest that you call the manufacturer for advice. It does not look too serious and I am sure that you can repair it with their input.