Checking Keel Bolts

[PaulJacobs]

In checking back through many topics on the Message Board over the past seven years, I noted some regarding checking / tightening the C34 keel bolts.  I confess that in the eight, soon to be nine years Nancy and I have owned Pleiades I have never checked - or tightened - any of her keel boats.  Shame on me!

I checked this site and determined that the hex nuts are 1 1/8", so I just ordered a 1 1/8" hex 1/2 inch "deep socket" that is listed as 5.7" long.  Although not specifically listed, I assume the "socket" portion probably takes up an inch, so the "effective" depth is likely about 4.7".  Hopefully, this will be deep enough to fit over all of the keel bolts extending into the bilge, and will still allow me to get full torque on their nuts.  Since Pleiades is currently on the hard, this seems like the perfect time to check the keel bolts, and tighten them if necessary, since the keel is blocked, and the entire weight of the hull is pushing down onto the top of the keel.

Question:  Does anyone know the recommended keel bolt torque?  I want to be sure they are "very snug". but not so tight that I may damage the fiberglass.

Paul

Pleiades, 1990 C34,
TR/FK, #1068
Yanmar 3YM30
FlexOFold 2-blade
Wickford, RI

[KWKloeber]

Paul

https://c34.org/search_gcse/?q=Torque%20

[waughoo]

Paul... do keep us posted as you work on this.  I would also like to torque my keel bolts.

[PaulJacobs]

Hi Ken,

The sites you referenced are for torque wrenches.  I need to know HOW MUCH torque to apply to the keel bolt nuts.


Although I do not have a torque wrench, I was planning on using the "poor man's version"; namely a fish scale attached to the lever arm of my 1/2" socket tool.  I am sure there is a proper name for the tool I plan to use, but it can best be described as looking very much like the old-style "brace & bit" - where the "bit" is a 1/2" male socket adapter that will attach to the 1 1/8" female 1/2" hex "deep socket" I have purchased, and the "swing arm" that looks like a "brace" has a 5" radius.

Thus, for example if I attach the "hook" of the fish scale to the 5" arm, and measure a 30 lb. pull on the fish scale, I will have applied 30 lbs. x 5" = 150 in-lbs. = 12.5 ft. lbs. of torque.  If, however the recommended keel bolt torque is, say 50 ft. lbs. then I will use two vise grips to secure a 24" long piece of pipe to the "swing arm".  Now, with the same 30 lb. force, but this time at 24" the torque on the keel bolt nut would be 30 lbs. x 24" = 720 in. lbs. = 60 ft. lbs.  I know that the fish scale goes up to 30 lbs., and that I can apply 30 lbs. of force with one hand while holding the tool with the other hand.

The only item missing is .... HOW MUCH torque do I apply?

Paul

Pleiades 1990 C34
#1068, TR/FK
Yanmar 3YM30
FlexOFold 2 blade

[ewengstrom]

In the thread that Ken mentions the torque spec was 107 ft/lbs.
When I had Ohana out of the water for a short haul this past spring I checked them and found that while I did get some movement out of them, it didn't take much to get them to the specified torque.
Hope yours goes as well.

[KWKloeber]

Hi Ken,

The sites you referenced are for torque wrenches.  I need to know HOW MUCH torque to apply to the keel bolt nuts.

Those C34 forum messsges discuss the recommended torque. did you read them?

How you attain those ft-lbs with a contraption is however you do it. No commenting on that.

BTW, the customized google search box (c34 main page, not on the forum) is an excellent first-choice to find already discussed info/issues on the forum, archives, wiki site, etc.   Sometimes the search box on the forum page shows up things that the home page google search does not.

K

[waughoo]

Paul,

Though your fish scale method will be accurate with the proper calculations and measurements, i might suggest renting a torque wrench from an auto parts store for the day.  Often, they have a deal where you get the rental for free when you bring back the tool.  The torque wrench makes this job a snap vs trying to meaure with a scale.

[Noah]

Paul,

"The torque wrench makes this job a snap...."

Alex, "bolt" and "snap" are two words i prefer not to use in the same sentence.

[waughoo]

Haha Noah!!  Didn't even put that together.  Especially a keel bolt 8-|

[PaulJacobs]

What a great forum!  I finally now know that 107 ft.-lbs. is the recommended torque for C34 keel bolts.

That is an interesting number.  My original idea involving a tool similar to a "brace & bit" coupled with a fish scale CLEARLY will not work.  With only a 5 inch long (0.416 ft.) lever arm I would need to apply 107 ft. lbs. / 0.416 ft. = 257 lbs.!   At 28 years of age I "might" have been able to generate 257 lbs. of force with my legs.  At 82 years of age "forgettaboutit".

So, I just ordered a torque wrench for the range from 20 ft.-lbs. to 150 ft.-lbs.  Since the lever arm of the torque wrench is "only" a little over 1 ft. long, I would still need to apply 107 lbs. of force!  Again, not likely at my age.  Thus, I will use: (a) a 5.7" long "deep socket" to hopefully engage the keel bolt nuts, (b) a 12" long "extension" to clear the cabin sole, (c) the torque wrench itself, and (d) a three foot long pipe over the torque wrench.  With a 3 ft. long pipe, I will "only" need to apply 107 ft.-lbs. / 3 ft. = 36 lbs. of force, which hopefully will not throw out my back.

It will be VERY interesting to learn how many of the keel bolts have come somewhat loose in the 8.5 years years Nancy and I have owned and sailed Pleiades throughout New England's fabled cruising grounds.  I have absolutely no idea whatsoever if the PO EVER checked the keel bolts, so it could be many more years since they were last properly torqued.

Paul

[KWKloeber]

Paul

For essentially a one-time use, I'd use Harbor Freight's $30 digital torque adapter that fits between a 1/2" drive socket and a socket handle or breaker bar.   It reads from 30 to 147 ft-lbs.   It even has a peak mode so after you remove the wrench you can see what you hit without doing headstands trying to monitor the screen.

-k

[Ken Krawford]

Advance Auto Parts has a tool loaner program.  They charge your credit card when you pick up the tool and issue a refund when its returned.
https://stores.advanceautoparts.com/
They have a 0-150 ft/lbs torque wrench - https://shop.advanceautoparts.com/p/powerbuilt-tools-kit-68-1-2-drive-needle-torque-wrench-kit-944050/9150050-P?searchTerm=9150050%20OR%209150000

[Jim Hardesty]

To All,
I think it's good to add your home port to the signature.  Perhaps there's a fellow member near by that would be willing to loan out such tools.
Jim

[Ron Hill]

Guys : I made my own keel nut wrench with a 5" "Snap On" socket.  It has a "T bar" handle (w/universal) - 105 Ft Lbs is a lot of torque !!

If your boat has never been checked you'll be surprised when you can get 1/4 to 1/2 turns on some of the nuts!!!   

The universal allow you to get at that aft keel nut!!  A Catalina Smile doesn't necessarily mean a loose nut, but more probably poor winter blocking - allowing the hull to rotate aft!!

A few thoughts

[Jim Hardesty]

Paul,
Not all the keel studs are the same length.  Some have been able to use off the shelf sockets others have had to make extra deep sockets.  Measure your studs before you buy a pricey socket.  Here is how I make mine.   FWIW  Not being the first owner of Shamrock, I started retorqueing the first spring I had her, most nuts took a half turn or more, next spring was very little.  I recheck every spring and sometimes get a little more.  Shamrock does not have any Catalina Smile.
https://c34.org/bbs/index.php/topic,7356.0.html
Doing a couple of searches will get a wealth of information.
Jim