When we last left our superheroes, they were feeling a lack of pressure.
So they need to meet the press.
I've got my paper-covered fins sandwiched inside wax paper, then foam. Clamp them up and leave them alone 24 hours.
When the fin comes out of the clamp, it looks like this:
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At this point, I like to remove the wax paper and let the fin dry several hours. It is not unusual for the fin to feel damp coming out of the press-moisture can be trapped in the press.
Once the fins are dried, it is a good time to use a hobby knife and trim off any excess paper extending beyond the balsa fin. It is now time for the stinky part--we soak the paper with thin CA glue. This will harden the paper and seal it.
WARNING: CA glue is bad to inhale, and it loves to bond fingers and other body parts. Do this step in a well-ventilated area. Left photo shows large fins before/after thin CA has been applied.
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After CA is applied to both sides, I like to stand the fin against something like a tin can and let the CA soak in and harden for 15+ minutes. Once hardened, the fin surfaces and edges can be sanded. I start with 150-220 grit paper for initial shaping, then move to 400 grit paper for final sanding. Round the leading and trailing fin edges. Sand the fin faces on a flat sandpaper surface (made one from sandpaper glued to smooth board). After fin edges are rounded, hit them again with thin CA because you probably sanded through the initial CA seal while shaping the fin edges. Then give a final 400 grit sanding to the edges and they should be ready for the rocket.
The typing paper removes all balsa grain, so the fins are much easier to paint and finish with this technique. I do this for the majority of LPR/MPR kits I build.
So they need to meet the press.
I've got my paper-covered fins sandwiched inside wax paper, then foam. Clamp them up and leave them alone 24 hours.
When the fin comes out of the clamp, it looks like this:
[
At this point, I like to remove the wax paper and let the fin dry several hours. It is not unusual for the fin to feel damp coming out of the press-moisture can be trapped in the press.
Once the fins are dried, it is a good time to use a hobby knife and trim off any excess paper extending beyond the balsa fin. It is now time for the stinky part--we soak the paper with thin CA glue. This will harden the paper and seal it.
WARNING: CA glue is bad to inhale, and it loves to bond fingers and other body parts. Do this step in a well-ventilated area. Left photo shows large fins before/after thin CA has been applied.
[
After CA is applied to both sides, I like to stand the fin against something like a tin can and let the CA soak in and harden for 15+ minutes. Once hardened, the fin surfaces and edges can be sanded. I start with 150-220 grit paper for initial shaping, then move to 400 grit paper for final sanding. Round the leading and trailing fin edges. Sand the fin faces on a flat sandpaper surface (made one from sandpaper glued to smooth board). After fin edges are rounded, hit them again with thin CA because you probably sanded through the initial CA seal while shaping the fin edges. Then give a final 400 grit sanding to the edges and they should be ready for the rocket.
The typing paper removes all balsa grain, so the fins are much easier to paint and finish with this technique. I do this for the majority of LPR/MPR kits I build.
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