Tips and Hints from "The DOC of LOC"

Finishing Polypropylene Nose Cones

All polypropylene nose cones have an inherently slippery surface and can be frustrating to finish if not prepared properly. I start by sanding the entire nose cone portion that protrudes out from the airframe with 240 grit sand paper. This sanding eliminates any slight imperfections, but more importantly, it also roughs up the surface for better primer adhesion. I never sand out the seam lines completely, I always leave a tell tale mark. After sanding, I wrap masking tape around the nose cones' smaller diameter, keeping it slightly away from the shoulder. The masking taped portion of the nose cone is then securely set into a piece of airframe tubing. The airframe tubing is used as a means for holding the nose cone when priming, sanding, and painting.

Next, wipe off the nose cone with alcohol and let dry. I use a good sandable primer that dries in 5-10 minutes on a sunny day. I don't use primers or paints that specify recoating must be done after 24 hours. Spray light coats of primer until the nose cone is covered completely, especially under the nose cone shoulder and let dry. Some plastic fuzzies will appear during the first few coats but these are easily sanded out. When the primer is dry, I lightly sand the nose cone with 400 grit sand paper and wipe off lightly with alcohol. After this, I then start applying some heavier coats of primer, giving the seam lines extra coats until they completely disappear. When dry, I lightly sand the nose cone again with 400 grit sand paper to a smooth finish. Next, I use a modeling knife and lightly cut around the shoulder to cleanly remove all the masking tape from the nose cone. This is done to eliminate the chance of peeling off the primer that is on the shoulder. I then remask the nose cone as before and set it securely in the airframe tube.

Before applying a coat of paint, I clean off the nose cone again with alcohol. When dry, I start spraying my initial light coats and build up to one final wet coat. After I'm satisfied with the gloss finish, I rotate the nose cone for a few minutes to prevent any runs. After the paint starts to cure, I set it aside to let dry for at least one day. After the paint is completely cured, I remove the masking tape as previously described. The result is a smooth, gloss finished nose cone ready for action. Works for me!!

The DOC of LOC.