Priscilla, our 1940 17-foot Barrelback became our lab rat today as we tested what we are calling a New Day at Snake Mountain Boatworks when installing a truly True 5200 bottom.
Rather than install her inner skin using 6 mm plywood panels, we are reverting to what is a truly very old school alternative: replacing the inner skin using 6mm strips of planking laid at approximately 45 degrees to the keel.
In so doing, we are able to deliver a bottom, the inner skin of which precisely matches that installed in Algonac in 1940.
Once we have dry-fitted each, approximately 5-3/4”-wide plank, everything will be sealed with four coats of Smith’s CPES, and we have applied three coats of Chris-Craft mahogany bilge paint to the inner surfaces, we will then install these planks bedded in mahogany 5200 using #6×1” Frearson-drive, flathead silicon bronze wood screws.
Once finished, the bilge will present exactly as it did when Priscilla left Algonac in 1940.
We will then proceed as we do with all SMB True 5200 bottoms, installing the outer mahogany planks bedded in white 5200 using #8×1-1/4” Frearson drive, flathead, silicon bronze wood screws.
Planking the inner skin produces a tighter, more rigid skin that follows the bottom’s contours precisely. Any interior squeeze-out will be removed using nylon putty knives before it, too, receives three full coats of Chris-Craft mahogany bilge paint.
Post this new day, SMB will make individually planking inner skins our standard for SMB True 5200 bottoms.
How many total sheets of plywood did you use to fabricate the 5.75 inch planks for the entire bottom inner skin?
Three.