Circumference: 520 -540 mm ( for men ), 490-510 for women
Negative buoyancy: 1000 - 1250 mm/s
Equipment necessary to fill balls :
1 football pump - plastic if available -
1 basketball filler needle ( 2mm dia x app. 30 mm long )
alternative : Spraying pump
e.g. garden spray -qualified to operate at 3 bar -.
A brass tube 2mm dia x 30 mm long must be soldered into the spray-jet
opening *. Such tubes can be bought in any do-it-yourself supermarket. Or ask
at any butcher shop to get their usual liquid-injection pump loaned and connect a
hose adapter with the filling needle.
1 brass tube 2mm dia x 200mm long *
(* tubes to be rounded on one edge before use )
1800 gr kitchen salt.
1 container with app. 5 l water heated up to app. 60°C (or 2160
gr salt in 6 ltr water for appr. 2 balls)
Filling Procedure :
- Press all remaining air out of the ball before you start with the filling procedure.
Completely dissolve the salt
before filling it into the spraying pump
-use mixing device--
- Insert carefully (soaped) filling needle into ball valve, rounded edge first. Press out all remaining air.
- Fill football pump with salt water and press into ball. Repeat process until ball feels pretty hard.
- Insert one end luted 200mm tube -ball valve down-.Push carefully through and allow remainder of air bubble to escape."Gurgling" must not be heard any more!
Again start pumping salt water into the ball until circumference has reached approximately 540 mm.After appr. 1 hour drain saltwater until circumference of 520-540 mm (for men) is reached.
Surface Treatment - to improve grip-
- Carefully cut away all fringes with small sharp knife.
- put ball in a small bowl and rub the whet surface with emery paper 600 until no shine is visible when held against light.
The pentagons faded due to rubbing can be restored by using EDDING 800 waterproof crayon. Ball will be ready for use after a drying
time of 12 hrs.
Red balls do not need any repainting.
Handling and Care:
To maintain its roundness the ball must be hanged up in a net!
From time to time or before start of the seasonal competitions ball must be thoroughly cleaned -with soap or similar-.
Repainting of pentagons also is advisable after a longer period of use.