Tip to tip paper

So as I have been reading a thought came to mind. I have heard of people fiberglassing their fins tip to tip after attachment. But couldn't a person do the same with paper? I would think it would add to both the strength of the fin itself as typical papering, and to the strength of the fin to body tube joint.


Kirk

I would say, yes you can. I have done a modified verson of what you are talking about, but only extended the paper a half of an inch onto the body tube after papering the fin. For the life of me, I can't remember which rocket, but it was 20 years ago and I think a tree ate it, IIRC.

Yep, been done...

Papering fins has been covered in a number of threads on here... I've detailed the process in my Dr. Zooch Vanguard Eagle Beta-build thread, including pictures and detailed explanation of the process... I take it you're talking about papering the fins from the tip of one, down to the root, across the body tube, and up the next adjoining fin to the tip of it... Sure it can be done, but I wonder really why you'd want to... a regular fillet would be just about as strong, or just reinforce the fillet area with paper to give maximum strength to the joint...

Later! OL JR

My thought was that if one were papering a fin anyway, then going from tip, across the body tube and to the next tip wouldn't add a lot of weight, but would have to be stronger than just a filet. (Though a filet could certainly be added for various reasons.) much like some do with fiberglass.


Kirk

My first thought is that the effort to benefit ratio is very high. I very rarely have fin-to-body joints fail; usually the fins just break.

10fttall said:

My first thought is that the effort to benefit ratio is very high. I very rarely have fin-to-body joints fail; usually the fins just break.

Click to expand...

Correct... I can show you how to make a balsa fin to paper tube joint that will require either the destruction of the balsa fin or the paper tube before failing, using NOTHING but yellow wood glue and Titebond Moulding and Trim Glue (thickened white glue, basically). The fin-tube joint, when done CORRECTLY, is NOT the "weakest link".

If done right, the fin will disintegrate and/or the outer layers of the tube will rip away before the glue joint fails... I've seen it firsthand. No sense in going to the effort to make that joint STRONGER when it is NO LONGER the first failure point! (the weakest point!)

Simple point of fact is, in a sufficiently bad impact or situation, SOMETHING is going to break, period. It may be the fin-tube joint, simply "popping the fin off the tube". It may be the fin grinding into whatever it's hitting (usually the ground) and being turned into dust or splinters. It may be the paper tube wall being SO stressed by the impact that the outer layers shear away with the glue and fin... it may be a combination of the two... point is, SOMETHING is ALWAYS the weakest link... and adding strength to something that's no longer the weakest link does NOTHING to enhance the strength-before-failure-point...

Later! OL JR