Thursday, February 8, 2018

ASP D Region Tomahawk Build, Part 4, Fin Shaping

When sanding a fin taper it's hard to see the edges on basswood or balsa. Here's one way to give a high contrast for a sharper sanded  line.

You'll be using a permanent marker on the leading edge. You don't want the ink to go deep into the wood, so the edges are sealed with CA glue applied with a Q-tip.
Cover the leading edge and down the sides a little below the pencil line.


Now you can apply permanent marker on the leading edge and down the sides. The ink stays on the surface and can be sanded off. If the wood wasn't sealed the ink would show through the finish paint.



Use a sanding block with 220 grit sandpaper.
Here's how the fin looks after a few passes. With the black ink it's easy to see the width of the sanded line.

As always, sand a little, check and sand a little more.



Here's the shaped fin, there is still a bit of black ink on the leading edge and sides. This ink is easily sanded off.

One small bonus of the CA coating, it strengthens the leading edges. This can be important if these were balsa fins.






All four fins, shaped and ready for a shot of primer/filler.

Basswood fins don't have a grain that needs filling. It's just slightly heavier than balsa. Many builders will cut and substitute basswood fins for balsa supplied in kits.

4 comments:

  1. I like that you're taking the time to properly shape the fins. Adds to the scale accuracy, a point underappreciated by many modelers today. Even more critical on ASP's larger kits, like the 29mm WAC Corporal and their newest kits, the 29mm Aerobee 100 Jr. and Aerobee 300, due to their thick, triple laminated fins.

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  2. I have two ASP kits waiting to be built - 24/18 WAC Corporal and the 24mm RP-3. Being a rather obscure - at least here in the US - Polish sounding rocket I queried ASP for more information about the actual RP-3 they graciously emailed me everything I needed. I'll try this technique when I get around to one of my scale ASP kits. Thanks Chris.

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  3. Hey Openroad,
    Is that the two stage WAC Corporal? Great build, but very challenging! And ASP has a MicroMaxx version of the RP3. Fun to display the bigger version with its' little brother in front. Love those MMX kits and motors: cheap, can be flown just about anywhere, and the small size presents a different kind of challenge. Unfortunately the number of vendors has seriously declined. Only two left that I know of: Fliskits and ASP. Hope they don't mothball the line. Laters!

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    1. P.S. Watch out for the decal on the RP3. Very thin and fragile.

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