Instructables

I bought 6 metres of ripstop nylon for my blimp envelope. What is the best way to seal the edges?

I've tried glue, duct tape, and a bit of heat sealing. It doesn't really work.

ANDY! (author) 3 years ago
i decided to use duct tape. It works.
orksecurity3 years ago
Old fabric-surfaced airplanes were stitched and glued, and then sealed with paint, if I remember correctly.
(In fact, according to some recent studies, that might be what took out the Hindenberg -- not the hydrogen at all, but a metallic paint which essentially wound up burning like thermite.)
ANDY! (author) 3 years ago
The stuff I have is airproof (or whatever the lingo is).
Re-design3 years ago
I've got a different question to you. Is ripstop going to be helium proof? I don't think it is. What are you going to seal it with?
That's a different question - It's not even air tight (but that wasn't what (S)he asked :-)

The material needs to be light and nylon or Mylar coated and the seams better than air tight if it is all that is holding the Helium.

Of course it may just be a bag to carry helium filled balloons.

I THINK you put the lifting cells inside, in mylar bags, but I may be wrong.
rickharris3 years ago
Heat but do it carefully
I will expand on my suggestion - Trap the edge of the cloth between two surfaces one on top and one underneath. These should ideally be metallic to act as a heat sink. Leave a couple of millimetres (say 1/10 of an inch) of cloth showing heat this with a candle, match lighter to melt the threads together.

The heat sink will protect the rest of the cloth.

A soldering iron works for this too and is easier to guide than a flame.
lizzyastro3 years ago
How about a flat felled seam
http://www.sewneau.com/how.to/flat.felled.seam.html

and then use a sealing tape like one of these:
http://www.pennineoutdoor.co.uk/catalogue.asp?cID=4
http://www.seattlefabrics.com/Seam%20Sealers.html


This will give you a strong seam that shouldn't leak.

Lizzy
mikeasaurus3 years ago
Fold edge over 1/2" and use a sewing machine to create a finished edge, or if you can use a heat sealer like the pros use.