Monokote fins?

[BlueNinja]

Has anyone tried making a hollow fin structure out of balsa or plywood, then coverieng it with Monokote? I have seen ths technique used on RC aircraft and was wondering if it is applicable to rocketry.



Blue

 

[edwardw]

I guess it depends on how you are intending to fly it. There was a thread on it, see here

https://www.rocketryforum.com/showthread.php?s=&threadid=8450&highlight=hollow+fins

Monokote is heat sensitive, so when you are heat shrinking it make sure you don't burn a hole through it. Also, if you hit it hard you might poke through.

How fast do you plan to fly it?

Edward

 

[BlueNinja]

I was just speculating on the idea, however I would use this for low and slow HP rockets if i could get it to work. Today I spent 15 minutes making a structure out of balsa and cutting the self adhesive Monokote to find that the sticky stuff is hard to get tight. It was really flabby. Maybe I could do hollow fins and glass them.

 

[Hospital_Rocket]

Remember monokote shrinks under heat. If you were not using trim monokote try a heat gun or hairdryer. I think you will be amazed by the results.

 

[BlueNinja]

It was the self adhesive kind. i plan on buying a roll of iron on and a heat iron.

 

[jflis]

I've used it many times and, in fact, hope to have a kit out that would use this method sometime in '05

 

[DynaSoar]

Originally posted by jflis
I've used it many times and, in fact, hope to have a kit out that would use this method sometime in '05

A kit with all the necessaries, including detailed instructions and explanations, would be a real service. If there were a simple one, I'd buy one just to learn the technique. Far better than buying lots of stuff just to try it once.

 

[mkmilion]

I remember on the Estes The Dude that the fins are mylar and that flys fine; except for on windy days.

 

[dr wogz]

I've monokoted (Ultracoat is better!) a few fins on my rockets, but then again, i have jsut as many RC airplanes as rockets, so I have a supply of covering!

Typically, though, I have jsut covered teh fins to avoid painting and sealing, and such. They look better, and teh covering does add some strength to the fins. I then jsut glue them in place once covered. Mask, and paint!

As for building up the fins.. We do this quite often with teh tail feathers of our planes. But our surfaces are about 1/4" thick. And we do sometimes have solid balsa for these parts. So, making a 'stick structure' for rocket fins might be a way to go, but realize that you're not making a big weigh savings, and strength / stiffness might be comprimised.

Oh, and Monokote is a brand name *(by Top Flight), but typicaly refferes to all heat shrinkable polyesther films. Carl Golberg Models make Ultracoat, and then there are shrinkable polyesther 'cloths' - silk covering.

There is another type of covering, that is sticky on the back, but dosen't shrink as much as Monokote.. Works the same though..

 

[BlueNinja]

Hey, how much does the heat shrink kind shrink?