Terrifying Keel Bolts !!

[Papawads]

We have 3 rows of 2 huge bolts holding the keel on, to our 2001 Jeanneau SO 43 DS, each row with a metal plate and nuts above.

The centre row have corroded to the point that the nuts are disintegrating, edges literally falling away. The others seem OK.

Questions:

1. Are these iron, not steel? Or maybe cheap steel not 306/316 SS? If so WHY????

2. Assuming this is a job to replace the nuts, should I renew the plate too. Its also rusty. Do you think the threaded bar, coming up through the hull, is changeable also? Can we use 316 SS?

3. Presumably I need the boat hauled out and sat on the keel when thus is done? Or being the centre ones, could this be done afloat?

This is mildly terrifying us, so any help greatly appreciated.

Thanks
Papawads

[Muaddib1116]

I would generally prefer to mess with keel bolts with the boat on the hard, but it is probably ok to loosen a center bolt in the water, one at a time.

That being said, this should definitely be inspected, but it's probably not as bad as you think. Those boats generally have really nice access to the bolts because of the shallow bilges. It looks like they were painted over, which is probably a bad idea. Also when steel rusts, it expands greatly, so that level of flaking could be very minor material loss.

I would remove the nut and washer plate, clean it all up very well, and inspect the threaded keel bolt for corrosion where it comes through the fiberglass, and where it was surrounded by the plate and nut. If that looks fine, then I wouldn't think about replacing the bolts themselves, just clean/replace the nut and plate and reinstall, torquing properly.

[Pete7]

Nothing wrong with using mild steel rather than stainless which has its own problems.

Our pictures can be seen in post 15 onwards.

https://www.cruisersforum.com/forums...ml#post3450615

Suggest you use an electric drill with a brass wire wheel attachment and give a couple of them a good clean back to shinny steel and see what its really like.

Chances are if you try to take them out, the bolts will undo rather than the nut. Couple of our go all the way through the flange on the top of the keel so you end up with a 1" hole in the boat if you unscrew the wrong ones. We have bilge keels so there is a big flange at the top to spread the loads.

Pete

[neilpride]

You can do better and without worries in the hard, better to retrofit with 316 ss plates, probably the bolts are ok, something you are going to see when the nuts and washers plates are gone, clean well the bolts and see if they are still solid, easy job..

Btw, ask Jeaneau for torquing specs.

[Adelie]

Since the bolts are cast into the lead it would be hoped that they were monel or inconel or similar. That way the nuts may be sacrificial for the bolts which are much harder to replace.

Stainless is subject to crevice corrosion which is why it may not have been used. Or it may just have been cost cutting.

While you nuts are flaking they aren’t almost about to fall apart.

If you want to try replacing them in the water then spray ONE down with some sort of stuck nut lubricant and let it sit for a week or 5. When you loosen it use a torque wrench to see what load it pops loose at.

If there are issues and you decide not to do the rest in the water you don’t have penetrating out sitting on all those nuts perhaps affecting your bedding compound.

[capt jgw]

I'd do it on the hard, but I'm up in Michigan where all the boats have to come out every winter no matter what. Gives us lots of opportunity to fix these things. The last time you did haul, was there rusty water seeping out of the hull to keel joint? If so, the bolts are likely rusting. The danger area here is not the visible part of the bolt in the bilge, it's the part buried in the fiberglass, especially if they're stainless. That's where crevice corrosion occurs. You can replace the bad nuts in water but I'd be planning on a haul out in the near future where you can properly assess the situation. Typical procedure after hauling would be to brace the keel so it can't fall over, remove all the nuts and have the travel lift come back and lift the hull off the keel. If your in a DIY yard it will only cost you lift time. Depending on the sealant they used, it may come right up or it may fight you. If it was 5200 or similar it might need some persuading. If the bolts look ok just redo the sealant and have them set the hull back on. If they're"J" bolts cast into the lead and need replacing you've got an expensive job ahead, way beyond DIY. I lucked out doing this on my Columbia 36. The keel is lead but a harder alloy and the bolts are hanger bolts (wood screw on one end and machine thread on the other) threaded into the lead. Easy to replace except the one that broke off when I tried to tighten it. That's how I knew I had a problem.

[deblen]

Would it be easier to split the nut vertically with a cold chisel?
The nut in the pic looks rusted enough that a socket wrench may just spin on the nut.
Use a 6 point socket of correct size.
First,soak nut with penetrating oil.
https://www.technologystudent.com/eq...ldchisel1.html

[JPA Cate]

The nut in the pic looks rusted enough that a socket wrench may just spin on the nut.

I've had that happen, taken a small mill file and changed the nut down one size. It's hard, if you're lying on your back on the garage floor, and working over your head, but should be quite do-able in the bilge.

Ann

[Phyrcooler]

Originally Posted by JPA Cate

I've had that happen, taken a small mill file and changed the nut down one size. It's hard, if you're lying on your back on the garage floor, and working over your head, but should be quite do-able in the bilge.

Ann

Yup… what Ann says… but that’s old school (like me!). If I needed to make new flats, I’d use a small grinder wheel vs a file. A file down in the bilge will definitely work you out and generate much foul language (but will work too).

[boatpoker]

Originally Posted by Adelie

Since the bolts are cast into the lead it would be hoped that they were monel or inconel or similar. That way the nuts may be sacrificial for the bolts which are much harder to replace. .

Jeanneau ... Cast iron keel.

[jeanathon]

Originally Posted by JPA Cate

I've had that happen, taken a small mill file and changed the nut down one size. It's hard, if you're lying on your back on the garage floor, and working over your head, but should be quite do-able in the bilge.

Ann

Dremel or a knock off is well worth the dinero.

[capt jgw]

Originally Posted by boatpoker

Jeanneau ... Cast iron keel.

That changes everything. They would be just regular bolts or threaded rod and very easy to replace if they don't break off.

[RaymondR]

Originally Posted by deblen

Would it be easier to split the nut vertically with a cold chisel?
The nut in the pic looks rusted enough that a socket wrench may just spin on the nut.
Use a 6 point socket of correct size.
First,soak nut with penetrating oil.
https://www.technologystudent.com/eq...ldchisel1.html

Use a small drill, say 1/8", to drill down vertically, and open if required with bigger drills, on opposing sides of the nut then use a cold chisel into the hole to split the nut. Piece of cake.

[TheOffice]

Use G10 for backing plates. No corrosion.

[jamhass]

use a nut breaker:

https://www.amazon.com/CRAFTSMAN-Uni...9407216&sr=8-6