BHM prop shaft bearing wedges and keel bolts loose

Davegagne21

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1985 BHM in changing the prop I noticed the wedges between the fiberglass keel and the outer bearing holder are rooted out. They were wood. And making new wedges I can not tighten the top nuts. Two questions. 1. Why are they wood and not stainless? Like meat issue or isolating bottom paint from anode? 2. I think to tighten them I need to drill a hole saw through the keel to hold the bolts inside the keel and tighten them re-fiberglass the hole saw plug back into the keel. But I was thinking if I could drill a hole in each bolt beyond the nut (towards the prop) I could drive a drift pin in the hole and tighten the nut without cutting the fiberglass. Any advice out there?
 

bluezone

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Looks like there's enough thread past the nuts to hold with vicegrips and tighten with an open wrench.
 

ssevenjohn

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I had to replace my bolts in a 31 bhm many years ago. drilled a hole around 1 1/2 " in the side of the keel parallel to the bolt. i was able to get the new bolt in the hole and got it home using needlenose vise grips until i could get a bolt on the end. did the same hole on the oether side of the keel for the bottom bolts. save the cutout...hull and deck it in and then glass over. the hole may have been 2".
 

plowin

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What model BHM is that? Its a different keel configuration than I have seen before on any of the 31’s. Most all of the 31s including that one from what I can see have a wet shaft tank. That said you can cut a hole into the side of the tank large enough to get your hand and a wrench into and simply tighten the bolts up. When it was initially made the heads of the bolts on the inside were probably glassed over and may have even been carriage bolts.

Once you have the bolts tight you can make a cover for the hole out of some G-10. I would just tap the glass and use some good quality 316ss fasteners and put cover on. This makes future stern bearing work a piece of cake. There’s no concern for water leaking by the cover since the tank is full of water normally anyway. If you go this route I would put a nice beveled edge onto the G-10 just so water flow is minimally disrupted.

Option 2 is to cut the hole and glass back over it when your done. I would go with option 1 personally.

The wedges are often made with cabosil or some like kind of product and the stern bearing is lightly bolted up squishing your chosen filler out and allowing you to shape it after it kicks. Your shaft angle seems significant in that picture and may not be possible using this technique however. Lastly, if you use wax paper between the cutlas bearing and the cabosil it wont stick to the cutlas once it kicks. Make sure that the deadwood on the keel is cleaned up and acetone so that the cabosil will stick to that and become part of the hull.
 
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Brooksie

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The wood wedges are a no-no. Maybe raised the engine in a swap or something. I would pull the prop, check and replace the cutlass as needed (itwill help with the lineup to have a tight cutlass), clean and sand the area. Glob on epoxy thickened with silica and gently slide the cutlass housing up the bolts till it touches after greasing it to prevent the epoxy from sticking to it. Wait for the epoxy to set. apply 5200 and bolt it up.
As to the bolts, you could remove the shaft to get at the heads if accessible from inside and tighten normally. That way you could replace the fasteners with proper bronze ones instead of stainless. Otherwise looks like you could double nut the exposed threads and still have room to tighten the holding nut.
 
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plowin

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Mudhakes the guy to ask about your repair hes extremely familiar with what you have there.
 

AGL

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At some point the PO had removed the bolts for the casting to replace the bearing and dropped the nut for the bottom one into the keel. You can't reach past the stern tube from the top to get to it, so he hammered a piece of wood into the bottom hole and used a stainless lag bolt that was eaten away by crevice corrosion.

That Chinese Ebay pipe inspection USB camera went into the hole easily so I could look around to decide what to do.

I couldn't leave it like that..... :-(

Attached are pictures of the tapered hole I cut into the side to get out the junk, to check out the bonding to the keel and casting, to add a tube down to the bottom of the keep to suck out any water that gets in there, and to install a double nutted bronze threaded rod and washers in 5200 for the casting. I left the threaded rod long on the outside so I can put a locking double nut on it to hold it when I back off the fastening nut when it needs to come off sometime. (I'll be 95 years old by then) I cut the hole the same size and shape as the inspection hole at my airplane rudder base, thinking that if I could get my hand in there, I could get my hand into the keel.

My grandson had to help out because the 1" thick lay-up made it hard to get my hand around the corner so I was getting all scraped up and we needed an activity to do together. He plays with Meccano and lot so he said, "look, a nut holding on the keel shoe doesn't have enough thread on it so whomever tightened it ran out of thread when they tried to tighten it! Not bad for a 10-year-old, grandpa beamed proudly. :) Fixed that too.

Since the plug was tapered, a layer of mat with lots of epoxy resin filled the saw kerf so the plug was about 1/6 below the surface of the keel when I bumped it in there with a heavy object. I skimmed it with filler when smoothing over the sandblasted bottom. PERFECT!!

Anyway, it all worked out well, but next time I would make the hole a bit higher and bigger.

Some pictures attached.

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Davegagne21

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I really like the tapered cutting idea on the fiberglass! Thank you very much
 

Davegagne21

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The wood wedges are a no-no. Maybe raised the engine in a swap or something. I would pull the prop, check and replace the cutlass as needed (itwill help with the lineup to have a tight cutlass), clean and sand the area. Glob on epoxy thickened with silica and gently slide the cutlass housing up the bolts till it touches after greasing it to prevent the epoxy from sticking to it. Wait for the epoxy to set. apply 5200 and bolt it up.
As to the bolts, you could remove the shaft to get at the heads if accessible from inside and tighten normally. That way you could replace the fasteners with proper bronze ones instead of stainless. Otherwise looks like you could double nut the exposed threads and still have room to tighten the holding nut.
I did try the double nut idea on the two longer top bolts. I tightened the bolts until I ran out of thread and his the shoulder of the bolts. My father in law remembers there is a backer block of wood in the inside and after 20 years it is rotted so I am going to cut open the keel and fix it right.
 

windwalker

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Brooksie

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I did try the double nut idea on the two longer top bolts. I tightened the bolts until I ran out of thread and his the shoulder of the bolts. My father in law remembers there is a backer block of wood in the inside and after 20 years it is rotted so I am going to cut open the keel and fix it right.
I meant double nut the bolts then use the jammed nuts to hold while you loosen the nut you want to remove. The rotted wood changes everything but I would still remove the shaft b/4 cutting into my keel. I've done it several times and it's no big deal.
 

Toolate

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@AGL what did you use to make the beveled cut? Jig saw or air driven body saw?
 

AGL

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@AGL what did you use to make the beveled cut? Jig saw or air driven body saw?
El Cheapo jigsaw, just a coarse wood blade. Hand-held, without trying to keep the base of the saw on the material. I'd recommend a similar bevel angle because it worked out well. If it were less, I'd wonder if I really managed to fill the saw kerf without gaps. This way, if the plug goes in too deep you can add more cloth/resin/filler. You would have to figure out a way to clamp it if there was a greater angle.
 

Davegagne21

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I cut the hole with a variable speed multi tool. I cut it at about a 30 degree angle and saved the pice of fiberglass to replace it. D61CC6BD-D78D-45BE-B9EF-102FAAFA5DB4.jpeg

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Davegagne21

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I used starboard to replace
The wood wedge between the keel and the cutlass. I also added starboard as bolt backers on the inside of the keel.
 

Davegagne21

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I made a scarf jig for my router to make
The wedge like you would use planking a wood boat scarf joint. It’s a 12:1 scarf.

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