1938 Chris Craft Runabout Special: How to Seal Bottom Plank Seams

We continue racing against the March 21, 2017, deadline, the day I begin towing my 1938 19’ Chris-Craft Custom Runabout to Tavares, FL, and the Sunnyland ACBS Show.

We have applies the first five of an eventual twenty coats of Pettit Hi-Build Varnish have begun the process of varnishing her above the waterline.

Mickey Dupuis, Custom Metal Restoration in Holyoke, MA, is about half-way to preserving all of the hardware, including Flyin’ By’s long cutwater.

Her original bottom has our attention now. We tested about 50 fasteners, finding all of them rock solid tight. The red enamel, not bottom paint, yielded to the Circa 1850 Heavy Body Paint & Varnish Remover quite easily. Removing her original copper bronze paint was another matter, but, finally, we reached our goal, bare wood from stem to stern and chine to keel.

The planking, which is original to the boat, is in near perfect condition. No splits or cracks could be found. The inevitable dings and gouges have been addressed using 3M Premium Marine Filler.

This morning, and what is the topic of this video, we are focused on sealing her bottom seams using Interlux Seam Compound for Underwater Seams.

Seam Sealer must only be applied to wood that has been primed. The three coats of CPES also acts as an excellent primer for this purpose.

Filling each seam completely is the goal. Reaching that goal will likely involve at least two applications of Seam Sealer, done 24 – 48 hours apart.

The tools for this task are simple: an about 5’ x 8” piece of thin wood of some sort, a flexible putty knife, Interlux 216 Special Thinner as the solvent, and a quart of Interlux brown seam sealer. We have “only” 80+ feet of seams to fill… What fun!