Serious Anti-Zipper Stuff

[DynaSoar]

Hobby Lobby International (the part that does R/C planes etc.) carries some carbon fiber tape. It applies with either epoxy or CyA. One wrap of this around the top of the tube and it should last quite a while.

Go to https://www.hobby-lobby.com/ and search for "carbon tape".

It'd also make for some very permanent striping tape, but kind of costy.

 

[gerbs4me]

thatnks for sharing this
this stuff will come in handy

 

[DynaSoar]

Doesn't make good striping tape. It's very stiff. When you open the package it springs apart and uncoils. it's real tough to get to lay flat all along the edge. Wrapped around is fine, but longways is a problem.

 

[powderburner]

Originally posted by DynaSoar
---real tough to get to lay flat ----

You may have to use the industry approach to assembling this stuff: working quickly (to stay inside the useful life of the epoxy, position the fiber plies, cover with separator ply, cover with absorber ply, cover with bag, apply vacuum to pull bag down tight. Use heat or time to cure adhesive, and start peeling off layers back down to the fiber plies.

Easier said than done.

 

[DumasBro2]

Carbon fiber tape may not be the best choice. While it is
lightweight and strong it is not very impact resistant. Kevlar® tape would better choice for this application.

steve

 

[DynaSoar]

Originally posted by DumasBro2
Carbon fiber tape may not be the best choice. While it is
lightweight and strong it is not very impact resistant. Kevlar® tape would better choice for this application.

steve

It's not supposed to take impact if it's anti-zipper, just prevent the tube from starting to deform and tear. If the top of the tube hits the ground first, it's going to have problems a band of light tape can't prevent.

Now, for around the base of something like a Weasel, with the fins sitting forward and the tail end guaranteed to hit first kevlar would be just the thing. In fact mine landed on an airport runway last weekend and got an impact crack in the paint halfway around the tube just north of the aft centering ring. This would make a good fix. Where can I get kevlar tape?

 

[rmpitzer]

I would call a relatively thin piece of strap...hitting the lip of an airframe......with enough force to rip the #$@% out of it....an impact.

Almost any fiberglass supply place should cary Kevlar tape. I purchased mine from https://www.fibreglast.com

-Rich

 

[DynaSoar]

OK, for an idea how well this worked, take a look at the application of it: https://rocketryforum.com/showthread.php?s=&threadid=12694&highlight=first+light

I launched it on an old At F50-4 yesterday. It peaked at about 500' at 4 seconds, just like the sim said. No ejection. 4 seconds later is was buried halfway up the body in the mud. 2 seconds later the charge went off. So it goes.

When I pulled it out, the nose had been pushed entirely up into the body. The edge of the body tube was intact, with the tape still on. Just past it the body was mushroomed out and shattered, either by the impact or the charge, or both.

So there you go. You can lawn dart 2.5 pounds of hardware at high velocity, and the top 1" of the body will survive intact.

Actually, the bottom survived intact too. Everything from the PML urethane transition (inverted tail cone) down was fine. I've got a coupler, so another 18" of 3" tube, a nose and a 3" centering ring, and we'll be back in business.