7/2/17 - Stem Repair

 



Its been quite awhile since my last Boatwrights' Log entry... been pretty busy and have fallen way behind with my log book. This week I'll try to get caught up to where I'm at. I'll begin with the work I did to repair the Dunphy's stem. The stem was in good shape except for the very top portion. It had rotted where it was concealed under the deck, butted up against the breasthook.  The two top lapstrake planks had some significant rot where they fastened to the stem, gunwale, and deck. Somebody had attempted to repair the stem cap using body filler, not a very good option for a wooden boat. I felt it should all be replaced.

        

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Since just the the top of the stem was damaged, I felt the best repair method was to make and install a Dutchman to the stem... that is, cut out the rotted area of the stem and replace it with a block of wood formed to match the profile of the stem. And also replace the ends of the two top planks that had rotted away. To begin I located and removed the screws fastening the two top lapstrake planks to the stem, pried the planks away from the stem using an oscillating multi-tool outfitted with a scrapper blade to cut through the adhesive. Then cut away the plank ends.

        

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Next was to make a new stem top (from white oak as the existing stem is made from) that matched the profile of the old stem top that had been cutaway and then fasten it place. I mounted it in place utilizing a scarf joint fastened with thickened epoxy and silicon bronze wood screws and reinforced it with a white oak block similar to the one directly below it that reinforces the bow eye. I also applied some 3M 5200 Sealant/Adhesive where the planks join against the stem.

        

       

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Next I replaced the four lapstrake plank ends. I used the old ones as templates for shaping and cutting out new ones. I shaped the gains (just a simple bevel), and scarf jointed (Lou makes it look easy) them together using epoxy thickened with colloidal silica and fastened them to the stem (and each other) with 3M 5200 Sealant /Adhesive and silicon bronze wood screws.

        

        

(click on an image to zoom in)


I finished the stem repair by shaping a stem cap from white oak, applying a thick coat of Dolfinite bedding compound to the stem to help keep the joint protected from moisture issues, and fastening the stem cap in place. Then gluing in some white oak bungs to cover the screw holes, and some sanding for final shaping.

        

(click on an image to zoom in)


 

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