Moody 31 Keel?

[alant]

On a recent survey, rust was found, indicating a small amount of movement at the fore & aft ends of the joint with the hull, with rust on the heads of the keel bolts".

Any Moody 31 owners know if this is 'normal'?

 

[Tranona]

Rust is common on Moody keel bolts as they are mild steel and sit in damp bilges. Usually respond to a good clean up and paint. Unlikely to have any effect on the integrity of the bolts themselves. Difficult to say about movement of the joint. Why not ask the surveyor whether it requires attention? After all you have paid for his expertise and he has seen the boat. Also join the MOA if keeping the boat.

 

[GrahamM376]

Rust is common on Moody keel bolts as they are mild steel and sit in damp bilges. Usually respond to a good clean up and paint. Unlikely to have any effect on the integrity of the bolts themselves. Difficult to say about movement of the joint. Why not ask the surveyor whether it requires attention? After all you have paid for his expertise and he has seen the boat. Also join the MOA if keeping the boat.

+1

The tops of most Moody keel studs and the nuts are usually rusty and if you try to take the nut off, the stud will be withdrawn complete with nut and chances are 99% the studs are in perfect condition.

 

[ditchcrawler]

By the reports on the Moody Owners website the owners who had the bolts withdrawn said the bolts were in good condition and they wished they hadn't bothered.

I rubbed the top of the bolts down and used black Hammerite on them and they look fine on my M31.

I had a thin line of rust at the front of my keel joint, wire brushed it, treated it with rust primer and no sign of rust so far.

By the way membership of the MOA is well worth the £20p.a. for the technical forum alone.

 

[robmcg]

Another confirmation of it not being an issue on the Moody 31. Not uncommon for the reasons people have stated above. The tops of the bolts can also be a braided back and then flow coated to stop them rusting further but I suspect hammerite would be just as good as ditchcrawler has mentioned. Great boat btw

 

[A_Sails_Pace]

By the reports on the Moody Owners website the owners who had the bolts withdrawn said the bolts were in good condition and they wished they hadn't bothered.

I rubbed the top of the bolts down and used black Hammerite on them and they look fine on my M31.

I had a thin line of rust at the front of my keel joint, wire brushed it, treated it with rust primer and no sign of rust so far.

By the way membership of the MOA is well worth the £20p.a. for the technical forum alone.

I know this is an older thread, but this is exactly what I have been looking for. Some simplicity in the approach. I have rusty keel bolts on my M29 and a slight corrosion at the aft end of my keel/hull joint and this looks like it's happened as a result of slight cracking in the paint/barrier. Some people have advised me to gut out the joining filler and whack in some flexi mastic and I just don't know if this is good advice or not? Bit of a mine field, this one.

 

[Tranona]

If that is all you have then you are lucky on a boat that age. Yes, the usual approach is to grind away the rust, dig out the filler, clean and use a flexible sealant to fill. Prime the bare iron and antifoul. Almost impossible to stop rust completely, but should keep it manageable. As suggested, the normal way of dealing with the bolts internally is to clean off the rust - it is usually just the nuts and maybe the washers underneath. If they look sound then paint. It is water in the bilge which causes the rust, not water coming in from outside.

 

[Birdseye]

There are two issues here - corrosion of the bolts and keel movement. The latter is inevitable to some degree as GRP is flexible and the bolts themselves can elongate under load as the boat rises and falls with the sea. For that reason a flexible seal between keel and hull is always used in construction. My last boat was Bowman built and they didnt skimp. They sealed the keel joint with a rubber strip the width of a sellotape and bonded onto clean grp and jkeep at build time.

As for rusting bolts, basic chemistry is that steel can only rust in the presence of water and air. So it you can get them cleaned with fresh water to remove salt, then bone dry and thick paint to keep them so, you will be ok. Modern grp boats should have bone dry bilges containing nothing more than dust anyway.