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-   -   Keel Question (http://www.sailnet.com/forums/gear-maintenance/79424-keel-question.html)

pirateofcapeann 10-03-2011 09:57 PM

Keel Question
 
I just went in halves on a Northstar 1000. Problem is that there is quite a gap between the lead fin keel ballast and the hull. The keel-bolts and hardware look to be stainless steel. I have a plan but need some answers before I can proceed:

1) Are the keel-bolts tapped or molded into the lead only or is there a carrying plate molded in there to carry the load?
2) The bolts look to be ĺ-inch. Not knowing what they are tapped into, I have no idea what my starting torque value on the keel nuts should be. I donít want to risk pulling the bolts out of the soft lead by over-torquing. Suggestions?
3) Iím leaning toward using 5200 to re-bed the keel as I had good luck with that on another boat some years ago. Anyone got any other thoughts?

Thank you in advance!

deniseO30 10-03-2011 10:24 PM

This is quite informative, Others will chime in soon I'm sure.

Projects: Below Deck: Replacing Keel Bolts | MadMariner.com


http://www.madmariner.com/files/imag...1510_PB-P2.gif

svHyLyte 10-04-2011 10:13 AM

Quote:

Originally Posted by pirateofcapeann (Post 782378)
I just went in halves on a Northstar 1000. Problem is that there is quite a gap between the lead fin keel ballast and the hull. The keel-bolts and hardware look to be stainless steel. I have a plan but need some answers before I can proceed:

1) Are the keel-bolts tapped or molded into the lead only or is there a carrying plate molded in there to carry the load?
2) The bolts look to be ĺ-inch. Not knowing what they are tapped into, I have no idea what my starting torque value on the keel nuts should be. I donít want to risk pulling the bolts out of the soft lead by over-torquing. Suggestions?
3) Iím leaning toward using 5200 to re-bed the keel as I had good luck with that on another boat some years ago. Anyone got any other thoughts?

Thank you in advance!

Are you looking at studs with nuts on them or bolts. Keel "smiles" are not uncommon and usually easily fixed with new bolts or nuts properly torqued. While a bedding/sealing compound is necessary it would be unwise to use 5200 as, someday, someone may need to drop that keel and doing so with a 5200 bedding can be very difficult and costly and, in some cases, destructive.

FWIW...

Tanley 10-04-2011 11:15 AM

You may want to take a minute to read these two threads:

http://www.sailnet.com/forums/gear-m...ge-issues.html

http://www.sailnet.com/forums/gear-m...el-repair.html

mm2187 10-04-2011 11:56 AM

How big of a gap are you talking an inch or only a small crack? Have you tried cranking down on the keelbolts to bring it back up? Does it come back up. Or are you looking to just fill the gap and call it a day?

pirateofcapeann 10-13-2011 12:17 PM

Thanks for your replies!!! That was a HUGE help and really gave me the full story! The gap is like a half-inch wide forward tapering to 0 aft, with rust staining the keel. The gap had been filled and who-knows what other maintenance, but the rust had me buggered. The bolts are S/S so I did not think that was the source, until now.

New plan. We intended to drop (lift the boat off) the keel a bit anyway, to facilitate cleaning and re-bedding the mating surfaces, but now maybe we'll open the gap a bit further to assess the health of the bolts. If we find any that are questionable, we'll drop it all the way so we can get at it. Then we'll cut the bad ones, flush with the top of the keel, dig into the lead around the bolts and install S/S coupling nuts and new bolt-tops, sealing, loc-tite-ing and re-filling the lead as needed. Re-bore the bolt holes only as needed to fit the shoulder of the coupling nuts. The keel nuts don't look to be backed by much more than standard S/S washers but I want to get some full-sized, (at least 1/4-inch thick S/S) plates to carry the load in the bilge.

Now that that's settled, I'm still wondering about torque and bedding recommendations.

ronspiker 10-13-2011 12:34 PM

The torque for bolts is set by the Type Thread Count and Size of the bolt and if there is any coating on the bolt threads. As an example a

3/4 in SAE2 with 10 threads per inch is torqued to 157 ft lbs if oiled it is 121 ft lbs, if coated with teflon it is 50% less than that..

Check the following website for guidelines. BOLTS AND TORQUE SPECS

Siamese 10-13-2011 12:47 PM

Rust? Do you know for sure that your keel is made of lead. Not steel? There are plenty of steel keels out there.

Your overall plan for repair may remain the same but may also address, to some degree, dealing with the corrosion if you have a steel keel.

celenoglu 10-13-2011 12:47 PM

Stainless steel 3/4 torque 95.9lb/ft for well greased threads. Add 10% if dry.

overbored 10-13-2011 01:00 PM

Quote:

Originally Posted by pirateofcapeann (Post 785806)

cut the bad ones, flush with the top of the keel, dig into the lead around the bolts and install S/S coupling nuts and new bolt-tops,

Be aware that not all keel bolts are fully threaded. there may be only a couple of threads below the surface of the lead.


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