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I have a '59 Sea Lancer. Some of the ribs in the stern are rotted up about 6 inches at the bottom. Not sure if I need to scarf in new sections, replace the entire rib (I don't think I'm up to that task) or install sister ribs along side the rotted sections. Appreciate any advice.

Skip

Remove the "bad" wood and get far enough back to good, sound wood and scarf new white oak into the old. Glue and screw the joint. Use white oak heartwood. Do NOT use red oak. Do not use sapwood white oak - it has zero decay resistance, you need the heartwood. You can also sister a piece of wood on top of what you just created or beside it to strengthen things. Definitely get the rotten wood out tho.

Andreas

Thanks. This may be a dumb question but when you scarf a rib is your cut side-to-side at an angle or top-t0-bottom?

cut from top to bottom

If you are working from the inside of the hull and the garboard planks and inner keel sisters (doublers) are still in place you will encounter a bit of an issue with the original fasteners. When you remove the rotted rib end there will remain a wood screw and a brass nail coming up into the keel sister (doubler), these must be cut away in order for the new rib end to fit properly against the inner keel... a job for a hacksaw blade (and skinned knuckles). With the garboard plank still in place the new screw must be driven from the bottom thru the garboard, thru the rib end and into the sister... use appropriate length screws. And a hint... at the splice joint, suggest using a #6 machine screw and nut to pull the joint together. Adhesive? I used epoxy on the splice joint ONLY. Also do not forget to cut a small 45* at the butt end of the rib to provide for limber hole (drainage along the keel).. and not a bad idea to seal the butt ends with epoxy prior to installation (retard water intrusion) .
Of course if the hull is upside down and the planking removed, disregard the above.

Joe B

Thanks Joe. Great information. BTW...I'm over in Manchester, MI.

This is for Skip from Manchester, MI... And I hope that I'm not violating the Dockside protocol by posting this... I would like to extend a invitation to visit an Antique Outboard Club meet In nearby Byron, MI on October 24th. Being a classic boat guy I'm sure that you will enjoy the company of a like minder bunch of guys as well as the spectacular collection of antique and classic race boats and motors that our host Mark has assembled. For meet particulars, see the "Upcoming Events" page at aomci.org. You can easily find me, a fellow Thompson owner, as I will be conducting the motor display awards program at the meet.

Joe B