[C320-list] Crack Between Hull and Keel

[Donald Lawson]

Thought this may help.  From the J109 website
Keel Bolt Torque Table

> Bolt Diameter	Torque Nm                  Torque Ft/Lb
> 1/2"                          26.0                                   19.2
> 5/8"                          66.0                                    48.7
> 3/4"	                         130.0                                  95.9 
> 7/8"	                        190.0                                   140.1
> 1"	                        224.0                                   165.2
> 1-1/8"	                420.0                                   309.8                            
> 1-1/4"	                460.0                                   339.3
> 1-1/2"	                 795.0                                   586.4
>  
> 
>    
> This Table is derived from information in Table A7 from ISO/DIS 12215‐9.2. These values are for well greased threads.

> Friction in the screw and under the bolt head makes up approximately 90% of the tightening torque and approximately 10% contributes to prestressing of the bolt.

> The user is cautioned to use good judgement in applying these values.


Don Lawson
"Mandolin Wind"  2004
Ventura,CA
















On Apr 30, 2017, at 1:12 PM, Art Harden wrote:

> I thought I would weigh in on the 320 Catalina smile. In past emails I inquired as to the torque values for the keel bolts. Based on all emails back-and-forth I think it was resolved to be somewhere between 100 and 235 foot-pounds. Using my mechanics mind and a history of torquing a lot of bolts, I decided to split the difference.
> 
> Today I finally managed to bring my sockets and torque wrench to the boat and check Tortuga. There are two sizes of bolts on the keel and I torqued them a different values. When I checked the large bolts I was surprised to find that some of them were as low as 70-80 foot pounds. Using my mechanics intuition, I torqued them to 175 foot pounds. When I hit the 100 pound mark, the nut still seem to lose to my way of thinking. So I kept going to the 175 which felt right based on the size of the bolt.
> 
> The smaller bolt at the back of the keel was only 40 foot pounds. I torqued it to 80 and that felt right.
> 
> My biggest surprise was how much I was able to actually torque each large nut.  I think only one nut was snug such that it did not move when the 175 foot-pounds was applied. 
> 
> I'm not sure if this helps anyone else but it will make me feel better knowing everything is snug. We will find out tomorrow is Tortuga goes in the water in the morning. 
> 
> Art Harden
> Tortuga Catalina 320
> 937-477-5544 (m)