Thursday, January 29, 2015

TLP Pershing #K046 Build, Part 23, Rear Fin Shaping

The rear fins on the Pershing are tapered.
The instructions show the center line of the taper in one drawing but don't mention to shape them.

I've been looking online for more scale data but didn't come up with much. The face card picture shows the fins flat and squared. I'll take extra time on the fins and get it closer.
The 1/8" stock is thinner than actual scale.


The balsa would be very weak at the thin tapered edges so I cut more out of 1/8" basswood.
The 1/8" thick balsa fin weighed .02 oz.
The new, stronger 1/8" basswood fin was .08 oz.
My shaping method is described in more detail in a Apogee Peak Of Flight newsletter article:
CLICK HERE

The outside edges of the fins were "sealed" with CA glue applied with a Q-tip. This prevents the ink from a marker from soaking into the wood. After the CA coat, the outside edges of the fins are then marked with a wide point permanent marker. This gives you a high contrast to better gauge the taper thickness when forming the "diamond" shape.
After shaping the fin tapers the remaining black ink is easily sanded off.
The marker is quickly passed over the edge. Go quick using just enough ink to darken the outside edges. Don't mark the root edge.

2 comments:

  1. I use basswood in places, too. I recently had to replace the forward fins on the TLP HARM model (hanger damage) and went with basswood this time. Gained about an ounce and a half but some of that was paint touching up other damage.

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    1. Hi Tim,
      On something this big (and clumsy) I don't think the balsa fins would last through the first hard landing. Going with basswood was the obvious choice.

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