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Building a Launch Pad Hawk Question about Fins

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Capt Pete

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The recommendation is to spread CA over the fins. Went to Lowes Home Improvement last night and they didn't have any larger bottles of CA. I currently use Zap CA and Slow Curing CA's, but they come in smaller bottles. Should I just Fill and Finish the fins for strength? Or can anybody recommend another idea, or recommend where I can get large bottles of CA at a decent price.

Pete
 

Daedalus

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Pete,

Please don't just use filler - it doesn't add strength. TLP kits built according to the instructions are good models - they are underbuilt if you just stick them together without hardening the materials.

An alternative to large amounts of CA is to cover the fin material with typing / printer paper. I have used finishing epoxy painted on the fins (both sides at the same time) and layed onto paper between boards and then weighted to keep it flat and ensure 100% adhesion. This is a little heavier than CA but very tough. I have had a TLP kit hit a concrete track and pop all the fins off with almost no fin damage.

Another trick on nose cones is to make up the extension as described but not CA it and then put enough epoxy (hobby shop type is fine) into the extension to fill the gap between the NC and the extension. Once set you can sand the paper and epoxy to blend it in to the plastic NC. Again this is really tough and replaces a little of the nose weight. If you epoxy the fins I would still use all the supplied nose weight along with the epoxy NC idea, it will help keep the CG in the right place.
 
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