last changed : 01/10/2003

Welding process :

•  Welding with a rope cutter
•  Welding with a hot iron
•  Welding with a hot wire
•  Welding with hot air

Welding with a rope cutter

The rope cutter characteristics can be found page : fournitures (in french)

• simultaneous cutting and welding of all the folded plastic pieces following the drawing from the xls file.
  This is the way described in the pages of this site :
  build a 4m (13 ft) diameter solar balloon
• simultaneous cutting with scissors of all the folded plastic pieces following the drawing from the xls file. Then assembling the pieces 2 by 2 with the rope cutter.

Welding with a hot iron

You need an iron more than 50 W (set around 400°C if all possible),
with a long and narrow tip.
The use is the same as the rope cutter.

Welding with a hot wire

from Bastien Massa :
"I did cut the folded piece with scissors following the drawing from the xls file Then assembling the pieces 2 by 2 with the hot wire (the one used to close the plastic bag the result is very good after a good adjustment of the wire temperature . Very regular and sturdy weld line (stronger than the plastic itself). The work may seem a bit tedious because you can only weld 30 cm at a time but the result is very good, even over my expectations the balloon lifted more than 3 kg weight with -8°C outside temperature."

from Jacques :
I used a bag welder machine. I bought to my wife but she did never use it so ..... It work fine, does a great job and cost only 30 bucks no more hassle with the tape tearing off.

Robert Campesat in Limoux (France) use a "Soude-sac à vide d'air" (vacuum bag welder) Calor modèle 242000 220V-85W.
The same for Frédéric Placin in Bordeaux (France) (see his french web pages https://fplacin.free.fr/sciences/BallonSolaire/BSintro.html).

Welding with hot air

from Alain Verbrugge : (for more details, see the french site https://ballonsolaire.free.fr/)
- simultaneous cutting with scissors of all the folded plastic pieces following the drawing from the xls file
- use a small table with non cutting: 1 x 1 yard maxi.
- place the 2 plastic piece edge to edge on the table.
- place 2 little wooden board (about 20 in x 10 in and ½ in thick minimum) edge against edge and following the length of 20 in. The wooden board must be heavy and large enough. They avoid burning or piercing the plastic on the table.
- let the plastic jut out between the wooden board of around 1/2 in so there is a length 20 in of plastic squeezed between the boards .
- tighten the boards with hand . do not let any gap between the boards.
- use an electric thermal paint striper (actually a paint burner 1600 watts with blower and 2 or 3 heating settings, 230 volts (may be it exist also for the 110 Volt ?).
pass it all along the edges of the plastic jutting out between the board at a speed and height just enough to melt the plastic (about 1 in). the speed is important to avoid melting the plastic too much. By using the right proportions of speed distance and heat , this job become very easy when getting used to it. La the weld is perfect linear and there is no hole...
warning do not aim the paint burner in the wrong place : it does burn .... after the weld cut the power and put the burner to a safe place it is still very hot!.
- to continue get the boards off.
- move the plastic forward leaving a small part of the previous weld (few inches). The join is perfect .

the best : perfect weld weight saving (no more adhesive).