Keel Bolt / Stud Leaking

[garvellachs]

Re torquing should be done on a regular basis anyway so crack on with that now.

That's interesting Javelin - it has not occurred to me that I should re-torque the keep bolts regularly. And I'm not sure how to do it anyway. The Bav instructions referred to in the thread require over 360nm or nearly 270ft lbs. That's a lot of torque to measure - my car wrench only goes up to 150 ft lbs I think - so maybe a 3/4 in torque wrench needed? How do you decide how tight to go on any particular boat?

 

[Javelin]

Hmm, you're quite right you probably will need to borrow a 3/4" drive and a power bar.
In truth it works like this, 90% of the keel bolt nuts we tweak don't move after a good pull.
However if they do its then time to research the torque settings for your boat.

On a vic38 recently I could move 4 of the easy to get to nuts very easily, probably even with a 1/2" drive.
So as a starter for 10 have a go with a 1/2" drive with a decent power bar.
If they move then time to find a 3/4" drive and the correct torque setting.

 

[Yngmar]

You don't really need a torque wrench for such large forces because it doesn't need to be super precise. You can do this with a luggage scale and a calculator. Simply measure the length of your lever and then calculate the force to be applied to the end of it. If your lever happens to be exactly 1m long, it's quite simple - 360 Newton force on a 1 m long lever gives you 360 Nm torque. Or roughly 36 kg on your luggage scale. Which is hard work, so better use a 2m lever instead so you only need to pull 18 kg on your scale (which is attached to the end of the lever in case that wasn't obvious).

This is a handy trick which I've spotted in the Selden manual for tensioning the foil on my in-mast furler :encouragement:

 

[garvellachs]

Hmm, you're quite right you probably will need to borrow a 3/4" drive and a power bar.
In truth it works like this, 90% of the keel bolt nuts we tweak don't move after a good pull.
However if they do its then time to research the torque settings for your boat.

On a vic38 recently I could move 4 of the easy to get to nuts very easily, probably even with a 1/2" drive.
So as a starter for 10 have a go with a 1/2" drive with a decent power bar.
If they move then time to find a 3/4" drive and the correct torque setting.

Thanks for the thoughts - I'll check they're tight with a 60cm breaker bar and take it from there!