Keel

Aug 3, 2012
2,542
Performance Cruising Telstar 28 302 Watkins Glen
Nice job! I agree with the use of 5200, and you will be able to cut through it and cut it out if you ever need. I have removed plenty of 5200 with my Dremel oscillating tool.
 

Ward H

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Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
The first 3 haul outs for winter with my O'day 25 I had the yard drop the centerboard while I tried to resolve why it kept sticking up.
Each spring when they installed it they used 5200 to glue in the wedges.
Must be some scenarios where it can be used but can be removed.
But,
I agree with NJLarry and others, I would/have only used it on the hull deck joint.
 
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Aug 3, 2012
2,542
Performance Cruising Telstar 28 302 Watkins Glen
Did you figure out why the centerboard was sticking?
 

Ward H

.
Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Finally did.
Turned out someone had "cut" to length a new clevis pin for the shackle that held the pendant line to the CB. They cut it 3mm too long. The trunk gets narrower nearer the top. The extra 3mm caused it to jam before it was all the way up.
Only found it by having yard to place the cradle on 12" blocks so I could crawl under the trunk. That allowed me to see a scratch on one side of the trunk near the top. Ordered a new shackle from Rudy and found the difference in length.
 
Apr 4, 2013
115
O'day 240 NY, NY (City Island)
Did a little more research on this. Contrary to earlier statements, 5200 was in fact specified and used by C. Raymond Hunt and O’Day in the design and construction of 302/322s (as well as the 240s and 272s), for the keel to hull attachment. See below.

upload_2018-5-24_7-48-37.png


So obviously everyone has their own boat and can use what they want, but particularly for the 302/322 keel joint, which was designed specifically for the strong adhesive properties of 5200, use anything less than 5200 at your own peril.
 
Feb 5, 2015
37
O'Day 302 Ottawa
The image is from the O’Day 302/322 owner’s manual but in itself doesn’t confirm that O’Day used 5200. 4200 also is a polyurethane sealant / adhesive.
 
Jan 7, 2011
4,723
Oday 322 East Chicago, IN
For what it is worth, the keel bolts on my O’Day 322 (hull 149) do not look like the drawing. I have the same drawing in my owners manual. I have a single row of large bolts...not 2 rows as depicted in the drawing.

Greg
 
Feb 5, 2015
37
O'Day 302 Ottawa
Same goes for the 302. It has three 1” stainless steel bolts and one 1/2” stainless bolt in a row running bow to stern. The O’Day drawing in the manual is a mystery.
 
Apr 4, 2013
115
O'day 240 NY, NY (City Island)
I am 99 percent certain that they are referring to 5200 because 5200, as a marine adhesive and sealant, is basically in a category of one: it has the greatest adhesive strength (700 PSI) of anything on the market by a margin of at least 50 percent. 4200 is recommended, per 3M, only when you want the option of "disassembly," so it would make no sense for O'Day to deliberately use that instead of 5200 for a critical joint like the keel/hull. Or really anything else for that matter, because there would be only significantly less strength.

Thinking more about this, and specifically the fact that the configuration of the bolts in the drawing do not match the way they were done at the factory, leads me to conclude that in terms of the integrity of the keel/hull joint, the bolts do not matter that much. The most important element of the joint is the integrity of the adhesive joint, which, if applied properly to achieve the maximum bond, can more than hold the entire dry weight of the keel without the bolts. This would make the bolts--and the configuration--less important, and really only necessary as a secondary, redundant attachment. I can think of no other reason R.L. Hunt would allow the factory to make that kind of change unless the bolts themselves didn't really matter that much--the adhesive bond does most of the work.

So while there is a lot of discussion about loose keel bolts, I would say that while that is extremely important, the condition of the adhesive bond is that much more important. If loose keel bolts mean that the keel has dropped away, even a fraction of an inch, from the hull, indicating that the adhesive bond is no longer intact, then no amount of tightening will be adequate--the bolts were never really designed to fully and solely hold the weight of the keel. In that case, even if keel bolts can be tightened, I would immediately haul the boat, drop the keel, and re-bed.
 
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May 17, 2004
5,025
Beneteau Oceanis 37 Havre de Grace
I am 99 percent certain that they are referring to 5200 because 5200, as a marine adhesive and sealant, is basically in a category of one: it has the greatest adhesive strength (700 PSI) of anything on the market by a margin of at least 50 percent. 4200 is recommended, per 3M, only when you want the option of "disassembly," so it would make no sense for O'Day to deliberately use that instead of 5200 for a critical joint like the keel/hull. Or really anything else for that matter, because there would be only significantly less strength.

Thinking more about this, and specifically the fact that the configuration of the bolts in the drawing do not match the way they were done at the factory, leads me to conclude that in terms of the integrity of the keel/hull joint, the bolts do not matter that much. The most important element of the joint is the integrity of the adhesive joint, which, if applied properly to achieve the maximum bond, can more than hold the entire dry weight of the keel without the bolts
As far as I can tell the tensile strength of stainless bolts is 30,000+ PSI. Personally I wouldn’t say they “don’t matter much” relative to 700 PSI adhesive. Also, although the adhesive is spread over a larger area, when the keel is bouncing around in seas or striking a sea floor, the loads (well in excess of the keel’s weight) are going to be concentrated rather than spread across the full adhesive surface.
 
Apr 4, 2013
115
O'day 240 NY, NY (City Island)
The tensile strength of the bolts is not the limiting factor. They could be twice as strong and it wouldn't make a difference. The limiting factor is the strength of the small area of fiberglass directly underneath the concentrated load of the small stainless plates underneath each of the three main keel bolts.

Under any combination of moment, tension, or shear the force on the fiberglass--and the likelihood of failure--is going to be greater if you rely on keel bolts and the small area of fiberglass underneath them, than if that same force is spread over the entire surface area of the sump via the adhesive. Particularly with regard to moment force, the as-built arrangement, which runs down the centerline of the keel sump, would create a greater force if you relied only on keel bolts because the moment arm, which would be the entire width of the keel sump, is double the length of the resisting arm created by the midline position of the keel bolt.

I'm not saying keel bolts don't matter. I am saying that the most important part of the keel/hull interface of these boats is the adhesive. Loose keel bolts are a problem, but a bigger problem is a bad adhesive joint.