Ring fin painting question

[hornet driver]

I've been thinking about doing a ring fin. Was just looking at another thread and o1d dude had some fine examples. His like many others have a nice crisp line between the inside and outside colors. How do ya'll manage this---including how do you get a good even coat inside the ring. I know there's a lot of masking required--I thought about painting the inside and then rolling some paper inside for masking---Thoughts--ideas techniques??? sorta flyin blind on this one--- Thanks, Hornet

[LW Bercini]

One of the detriments to getting a good masking adhesion on the interior of the ring is the irregular interior surface and knurls along the edges. It tends to give the interior a concave profile. Spend plenty of time sanding and sealing the interior. Sanding the inside of a ring is a PITA. I created a sanding jig from a section of Venetian blind which did help. Of course you have be careful to support the ring sufficiently so that you do not create a crease.

In the case of my Dead Ringer, I cheated with the 2 colors: I used trim Monokote.

http://www.rocketryforum.com/showthr...833#post309833

Because of the color scheme I chose, I painted the rings separately from the body and fins. I used a dowel and "tacky putty" (the stuff we used to use to put posters on our dorm walls); attaching the dowel to the exterior of the ring temporarily. This attachment method gives you great mobility for orienting the ring for painting

But if you want to paint the interior and exterior different colors, you should use small segments of masking tape as you mask the interior - no more than an inch at a time, taking time to press down all the edges.

[o1d_dude]

First I paint the entire rocket in the primary color, then mask off the area I want to protect, and then shoot the trim.

Tube fins require a lot to tape to accomplish this. I trim the masking tape down fairly close to the edge of the tubes so that the spray will reach into the "corners". If you leave the tape untrimmed, the "corners" will get only a light color coat due to the turbulence where the tape meets the fins. Creates a bit of a dead spot.

[hornet driver]

That's really, really clean--I'm gonna have to work on this idea! Thanks for the pics -Hornet