Association Forum - Hull Deck Joint

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

Catalina 25 Specific Forum

Hull Deck Joint

New Topic

Topic Locked

Printer Friendly

Author

Topic

Gloss
Master Marine Consultant

Member Avatar

USA
1916 Posts

Initially Posted - 07/16/2003 : 15:38:33

The other day I was asked by my sailing instructor, who owns a beautiful Sabre 34, what kind of hull/deck joint was on my 89 model.

Anybody out there know the answer to this?

What are the various options, and which is superior. I have seen this topic discussed in advertisements, but that was not a consideration when I purchased my 25. Catalina's reputation, and this fine group was more important of a consideration at the time

Thanks

Frank Gloss
89WK/TR

Edited by - on

matsche
Captain

Members Avatar

USA
280 Posts

Response Posted - 07/16/2003 : 22:15:48

Frank:

I could only find a little info on hull/deck joint from Practical Sailor. They state:

"The hull-deck joint on some models used self tapping screws rather than through bolts. Several readers experienced rain and spray leaks along the rail."

Practical Sailor seems to harbor a grudge against Catalina based on the various articles I've read, so I wouldn't put much stock in it.

John Matsche 1985 TR/FK #5171

Edited by - on

Douglas
Master Marine Consultant

Members Avatar

1595 Posts

Response Posted - 07/17/2003 : 00:05:46

http://www.ays.com/catart1.htm here is some interesting info.

Doug&Ruth
Triska (Alberg 29)
Tacoma Wa.

Edited by - on

Brooke Willson
Admiral

Members Avatar

USA
983 Posts

Response Posted - 07/17/2003 : 01:06:48

Frank, I don't know the answer to the question, but I'm sure it is something less substantial than on a Sabre. I don't know your friend, but it sounds suspiciously like a discount of your boat. Of course the C25 has a less sophisticated joint: it's not designed for circumnavigation.

And my Camry doesn't have a 453 V-8 and four wheel drive and a snowplow option . . .

Just make sure you move your boat more often than he moves his!

Brooke

Edited by - on

Gloss
Master Marine Consultant

Members Avatar

USA
1916 Posts

Response Posted - 07/17/2003 : 17:58:16

Brooke,
My friend was not dissing my boat at all. He was really impressed and liked the boat. He is trying to teach me lots of stuff and wants me to sail, and learn more. Just because he has a Sabre doesn't mean he is a snob.
He does realize what a good value our boats are. He does sail his Sabre a lot.

Frank Gloss
89WK/TR

Edited by - on

Leon Sisson
Master Marine Consultant

Members Avatar

USA
1893 Posts

Response Posted - 07/17/2003 : 22:32:34

Frank,

Re: "The other day I was asked ... what kind of hull/deck joint was on my 89 model."

On my 1979 Catalina 25, the hull/deck seam appears to be shoe box, bonded with polyester resin thickened with wood flour, reinforced on the outside by the aluminum channel rub rail, and fastened with either stainless steel #10 or larger self tapping screws, or 1/4" thru-bolts. Whatever they are, I'm guessing they're on 4" to 6" centers. Those of you who have worked on your rub rail would know more about how it's fastened. I think those are the same fasteners that clamp and back up the bond of the hull/deck seam. The details are kind of hidden by the hull liner and that strip of teak interior trim where the hull and deck meet. As production hull/deck seams go, in my opinion it's a good one.

Re: "What are the various options, and which is superior? I have seen this topic discussed in advertisements, ..."

From The Complete Book of Sailboat Buying, Volume I , 1978, Belvoir Publications, Inc.:

[ My comments are italicized in brackets. ]

" Joining Deck and Hull 

Probably no single topic stirs up more partisan response and pigheaded stubbornness than how the deck molding is attached to the hull molding. In the early years of fiberglass boatbuilding, deck and hull were almost universally rigidly fiberglassed together. Although the exact technique varied widely, the general principle was to overlap the hull-to-deck joint on the inside of the hull -- sometimes on the outside, although this requires more cosmetic finishing -- with several layers of fiberglass cloth, in effect making the hull and deck one piece. Once again, this is fine in theory, but in practice, it is still a secondary bond and therefore suspect. Thousands of hulls and decks have been joined in this manner, and the percentage of failures has probably been relatively small, but they do occur.

The subsequent variations on chemical bonding are almost infinite. There are inward turning flanges [ Hunter ], outward turning flanges [ Sunfish ], coffee can lid flanges. [ a.k.a. "shoe box", Catalina ] Some are glassed together with cloth, others use polyester putty between the flanges [ Catalina ], some back up the chemical bond with fasteners, such as self-tapping screws or through-bolts. [ This is now pretty much standard practice. ]

Failure of a chemical bond in the hull-to-deck joint can be catastrophic, with complete failure of the secondary bond resulting." [ Long pointless anecdote omitted. ] "We have seen serious hull-to-deck separation as the result of collision with other boats or impact with a dock. In most cases the break has been the result of a fracture of the secondary bond rather than the failure of either the hull or deck molding.

By far the simplest and strongest [ remember, this is an opinionated topic ] hull-to-deck joint is the inward-turning hull flange at deck level, with the deck laid over it and the two thoroughly bedded and through-bolted at close intervals. This joint can be covered by a wooden toe rail -- whose through fastenings form part of the mechanical hull-to-deck joint, or it can be covered by an aluminum extrusion specifically designed for the purpose.

The use of a powerful adhesive bedding compound such as 3M 5200 gives this joint much of the strength of a chemical bond without its brittleness, and through-bolting at intervals of less than a foot -- six inches is reasonable bolt spacing -- effectively ties the two moldings together mechanically. Variations on this joining theme are becoming increasingly popular on everything from the least expensive boats to the most expensive. Hunter uses it, and Swan does too.

It is not reasonable to condemn rigid chemical joints out of hand. Few boats ever find themselves in the position where hull and deck are strained badly enough to cause separation. However, for a boat designed for serious offshore or coastal use, whether racing or cruising, we'll take a through-bolted, flexibly bedded hull-to-deck joint every time."

-- Leon Sisson

Edited by - on

Brooke Willson
Admiral

Members Avatar

USA
983 Posts

Response Posted - 07/18/2003 : 06:21:53

Sorry, Frank: didn't really mean to diss your friend. I have met some snobs at the marina, and I'm glad your friend isn't one of them!

Brooke

Edited by - on

Gloss
Master Marine Consultant

Members Avatar

USA
1916 Posts

Response Posted - 07/18/2003 : 08:05:49

Leon,
Thanks for the information

Brooke,
I belong to a sailboat club where everybody has to work so many hours per year. My friend puts in more than his fair share, including teaching basic keelboat as a money raiser for the training fleet (for kids) Nothing snobbish about that.
You should see his Sabre, really nice. Probably the only boat I have seen which could get me away from having a Catalina

Frank Gloss
89WK/TR

Edited by - on

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.