Keel bolts

[davew190]

I have not changed the keel bolts on my boat, I've had the boat about 8 years. I think they were changed before I brought it. What’s the recommendation on life span?
Its only a small yacht (19ft)
thanks

 

[tillergirl]

Ah, now there's a good question. Well worth doing a search for previous posts on this subject (which have been quite frequent). A few on here (wooden boat owners) talk about checking every ten years but there are telltale signs on a wooden boat that can raise concern or relax you depending on what you can see - by that I mean rust weeps externally at the keel joint; ditto if water is obvious coming up the bolts. If you have that, I would be thinking it was worth a look at the bolts.

If its a boat made of that other stuff -- err what's it called, er gliberfast? (Sorry), I don't have any personal experience. However on the basis that a keel bolt won't corrode with moisture, and if its steel, corrosion will take the form of rust that has to force itself out somewhere, a bit of an external look see is still a good idea.

Tell us something about the boat...

 

[oldsaltoz]

<<<What’s the recommendation on life span>>>

What's the length of a bit of string?

Next time your on the hard, remove 'one' bolt only, check it's condition and replace it, do this for each bolt one at a time.

Do this a year after new bolts have been installed then every three years, or till you detect some deterioration, then revert to the annual check.

Replace any bolts showing signs of corrosion or (crevice cracking if stainless). If you need to lubricate the bolt / nut, add the oil to the bit in your hand, never put oil down the hole, add a dab of sealant when replacing to reduce water getting at the threads and surrounding material, if your paranoid, paint them with some flow-coat, this help seal them.

avagoodweekend......

 

[tgalea]

Just a question here because i've never done this on my both either.

We refer to these as keel bolts.. and extracting a bolt for inspection.

How does this work exactly. I was always under the impression that the actual bolts are part of the keel at it's the nut we tighten etc..

From my bilge i see all the bolts for the keel.. How would it work, i mean if i turn anticlockwise what would happen, the nuts get undone or the bolt starts coming out ?

On the other hand... if all looks ok don't you think it a big risk to be messing with them ?

Yours opinions would be greatly appreciated as usual.

Regards
Tyrone

 

[26ft_bathtub]

On my keel/cb-casing the bolts are embedded in the keel, and the nuts can be removed as you describe.

Never taken off a nut to have a look, but I don't think I'd be able to inspect the bolt that way, except maybe superficially.

 

[tillergirl]

There are two common ways of bolting on the keel. One is through bolts, up from the bottom with either a nut or head recessed into the bottom of the keel and another nut inside. Removal is to undo the inside nut and drive out the bolt from inside. Second is a stud which is threaded into the keel and has a nut inside. So check the underneath of your keel for recessed heads - if so you have bolts. If you can't find recessed heads you either have studs or very well concealed heads. A stud shouldn't really undo by turning the nut inside; the nut should come off and with all the nuts off you drop the keel. There is the possiblity if you have enough of the head showing inside to add a second nut to jam the first and then try to undo the stud by turning the first. There are other ways with galleries but I don't think they are very common.

As to removing the nuts and looking at the heads of the bolts - the one of mine that looked the best was in the worse condition! Another nut put a slight twist in the head of the bolt before it came free! But, hey, it had been there 40 years.

 

[kestrelleda]

I had a long-keeled wooden boat a few years ago and no idea how the keel was fixed on. There were nuts to be seen so I tried unscrewing one and a complete stud came out with it. Others I tried needed a locknut. I removed a few samples like this along the keel and they were good enough to reassure me the keel wasn't going to fall off. Saves dropping the keel if you have this arrangement.

 

[andywebb]

I am planning to "drop" the keel on my boat shortly, it is cast iron with 12 x M24 studds tapped into the keel with bearing plates/nuts in the floor of the hull.

Half of the nuts loosened, but the other half were corroded to the studd so the whole lot came out. At least with the use of a crane I hope to be able to lift the boat clear and remove the remaining studds by locking off two nuts.

In order to remove the nuts I enlisted the help of a friend and taking it in turns, one of us hung off the end of the lever arm on the box spanner exerting pressure in a bouncing movement whilst the other used a large hammer and sacraficial piece of metal to protect the head of the lever arm and continually whacked the spanner. WHen the co-ordination is right the nut released a quarter of a turn at a time until eventually off it came, plenty of WD40 too.

We had to extend the lever arm with a stump of scafold tube too.

My question is can anyone recomend the best product for re-bedding the keel to the hull please ?

 

[William_H]

You obviously need to know and understand how the keel bolts work. ie studs or through bolts iether right through the keel or through a flange at the top of the keel.
You might consider simply adding more keel bolts by drilling from the top through the hull or keelson and into the keel if it is cast iron and tapping a thread into the keel. You then fit a stud or bolt of suitable length.
2 or 4 more keel bolts should ease your concern about the keel falling off. I would caution against pulling the keel off as it can turn into abig job cleaning it up and refitting it. olewill

 

[andywebb]

The keel has a large flange housing the studds. The keel has been in place for 20 years, the plan is to remove the old bedding material, replace the studds and re-bed again. I agree, there is going to be a lot of cleaning up but I would prefer that option as I have not got the tooling or confidence to drill/tap M24 holes !

Does anyone know what the professionals use to re-bed the keel ?