The objective here is to build an envelope using Polyethylene film.
A blimp outline (from the Mylar experiment) is used to get a basic blimp profile.
Bear in mind that this is not a real gore outline.
On going around the outline with a hot iron the edges are sealed.
The iron is at the melting point of the film but by using a layer of waxed paper
the film is fused but not melted through.
One needs to keep the iron moving along the paper; best seals are when the paper
must be peeled off the film. I did both sides of the seam.
The photo shows a small iron used by quilters; it has a temperature control on it.
Inflated envelope is about 6 feet (1.83 m) in length. Upright it's a blimp, flat wise it's an aerodynamic lift body!
I think this film has potential; but it needs more research.
I found it very diffcult to find the last leak; I seal one leak and another area leaks. I decided to
try wider seams; see below.
One-inch width strips are cut from the polythylene film for testing various adhesives and sealants.
Tested after 24 hours. Most surfaces where sanded with 220 grit sandpaper.
None of the sealants stick to the surface of the film.
| Adhesive | Ashesion | Comments |
| Scotch Permanent Double Sided Tape | good | not sanded |
| UHU Contact Powerglue | none | sanded |
| Loctite Flexible Adhesive | none | not sanded |
| Testors Plastic Cement | none | sanded |
| Testors Plastic Cement | none | not sanded |
| Gorilla Glue-Dries White. | poor | sanded |
| Gorilla Super Glue | very good | sanded |
| Scotch Max. Strength Adhesive | none | sanded |
| Devcon 5 Minute Epoxy | very little | sanded |
| Loctite Clear Silcone Sealant | none | sanded |
| Z Vent Sealant | none | not sanded |
| 3M Scotch Weld-Neoprene 1300 Sealant | none | not sanded |
Here the seams are 1.25 inch (3.18cm) wide. The envelope has been turned inside out
so that most of the seam material is on the inside of the envelope.
It is helpful to try to pull the seams apart by hand as a first test. Inflating the envelope and
having them pop apart is time consuming.
After a number of re-seals the envelope is complete.
If I find another #$@%&** leak it's getting Super Glued!
