I got this PM from Alan today, since it's relevant and might be helpful to others working on 18ft SCs, I'll post his question and my reply here:
Hi Jb, please provide more info and what year Starcraft beefed up the hull to correct cracking problems.
I have 72 18' nova and starchief. Thanks, Alan
Unfortunately, it isn't exactly factory supported data. It's based on what's been SEEN here as people drag old SCs home, tear into them and post pix of their hull's support layout on I boats. They have the reinforcement rib/hull plates or not. Have rib end or hull cracks or not.
Since this is relevant to your build and others may benefit from it, look for the rest of my reply in your latest SC topic about your Starchief.
Thanks
John
Watermann had rib end or hull cracks to deal w/ and added the plates w/ plenty of details. Grandad also shows where and how he added plates to his Holiday, as did ClassicCat.
You can search thru the 18+ft SC builds posted in
Starcraft Rebuilds and Restorations, they're all here!, and see which ones had plates, or didn't (most of them).
I apologize but I can't recall which topic showed the result of a factory rehab (specific reason may have been noted) on a hull that fell w/in the timeframe of known years that did not have the plates, as evident by other boats/hulls posted here. When she tore out the deck, the plates were in fact installed. She remembered her dad (or someone) talking about having some problems w/ the boat at some point and it was sent back to Starcraft and they did unspecified work to it and returned it in water-ready condition. Presumably that's when the plates were added.
IIRC, the factory change started in the 80's, but a firm start date hasn't been determined w/ 100% accuracy to the best of my knowledge. In the collective opinion of those that have torn into them, and those that frequent the SC tin dry dock, the problem typically starts w/ rotten decks and transoms. If those problems are ignored, metal stress and strain begins to fatigue certain areas of the hull: splashwell corners/seams, transom corners/seams, gunwale edges, rib ends and chines. Other primary contributing factors could be 'heavy abuse' or use in severe conditions of a sound hull. But even moderate speeds thru moderate conditions could easily stress a hull w/ compromised components if done repetitively over long periods of time. Including trailering.
Many haven't been able to find the hull cracks until after they stripped the paint off the hull. Some are extremely, fine, hard to find cracks. Some have been found to have just started, and only extend out to the edge of the rivet head, so until the rivet was removed, there was no hope of seeing the crack.
ClassicCat added vertical stress relieving panels (added rigidity to the panel below the gunwale) to reduce the possibility of chine cracking when he addressed rib end cracking and hull cracks. He did GREAT diagrams of what he planned to do and how, as well as a good photo record.
Generally speaking, prior to the late 70's, I'd examine all the ribs and adjacent hull areas for signs of damage. After the mid-80's I'd expect to find the rib ends protected by factory plates.
Fortunately, Watermann, ClassicCat and Grandad are all still active, and all 3 did really great jobs of documenting their repairs. Anyone working on big tin boats would learn a great deal going thru their topics. FWIW, 2 of those guys won the SC Splash of the Year, and when he gets back to working on it, ClassicCat is likely to be a contender when he finishes his rebuild.
John
