How to mask a PT boat hull ??

A technique I've seen used is to position the hull on a table top so the boat is mounted firmly and won't easily move.  The boat should be positioned so the desired waterline is horizontal to the table top.  Then, using a pencil mounted to a wood block of the same height as the waterline, move the pencil "scribe block" around the boat placing small marks at the boat's desired waterline.  Join the peck marks with tape and a little eyeball english.  The peck marks may need to be sealed if there will be no black "boot top" to cover them.

Go along the natural waterline ... look at the photos of PT-109 on a cargo ship ... You'll CLEARLY see where the waterline would be.

Garth

If you are talking about masking off the waterline on an 80' ELCO hull like the Revell PT 109 or the Italeri PT 596, here's how. Using a pencil, mark the position of the waterline at the bow, stern, and point at which it crosses the chine. Using 1/16" wide striping tape, start at the stern and run the tape to the point at which it crosses the chine. Turn the hull upside down and continue running the tape to the bow as shown on the drawing below. Hold the hull so you are looking at the side and determine whether the line of the tape looks straight. Adjust the shape of the V on the hull bottom until it does. Once you're satisfied with the straightness of the line, repeat the process for the other side and run a piece of tape across the stern to connect the two side tapes. Mask off the upper portion of the hull with masking tape and paper, then paint the bottom.

i73.photobucket.com/.../lines-1.jpg

Al Ross