High quality materials for building your own ballast system.
We are selling very nice carbon tubes that can be used to build your own ballast system. We have four different diameters of carbon tubing. Two of them are sized to accept our tungsten cylinders and the other two are sized to fit lead weights cast into copper plumbing sleeves. We are not currently selling cast lead weight. However, in the ballast specs, we list their weight as well as physical dimensions as a reference. The carbon tubes have been categorized so that you can easily find the proper size for your chosen ballast material.
The tungsten weights are the most convenient by far, they are pre made, have a higher material density than lead and are non toxic. The downside is cost. Lead is the economical choice for ballast but requires casting. The ballast tubes that we have provided for use with lead weights are sized to accommodate weights that have been cast into either 1/2" or 3/4" copper plumbing coupling sleeves. There are numerous places across the web to find information on casting your own weights. Please do your homework though, as mishandling this material is dangerous.
A note about density vs atomic weight:
The Periodic Table tells us that tungsten has an atomic weight of 74 while lead has an atomic weight of 82. Typically, the heavier an atom is, the heavier a material will be when made from those atoms. Tungsten however is an exception to the rule due to the tighter arrangement of its molecules. This tighter arrangement results in a higher density material, 0.70 lbs/in3 vs. leads 0.410 lb/in3. The good news here, for glider pilots is, the ability to have greater mass in a smaller area.
- Currently we are stocking tungsten ballast cylinders in two different sizes.
Ballast Specs: diameter X length - weight :
- Tungsten 19mm X 30mm (0.752" X 1.256") - Weight: 153.6g ( 5.42oz)
- Tungsten 25mm X 38mm (1.002" X 1.542") - Weight: 338.5g (11.94oz)
- Cast lead 18mm X 28mm (0.704" X 1.109") - Weight: 73.71g (2.6oz)
- Cast lead 25mm X 40mm (0.965" X 1.612") - Weight: 195.4g (6.89oz)
The carbon tubes are constructed of a combination of unidirectional and woven carbon fabrics and are mandrel wound. The tubes can withstand rather extreme tension, compression and torsional loads as well as being very resistant to crushing and splitting.
Carbon Tube Specs: id x od x L
- 20 X 22 X 1000mm (0.787" X 0.867") - For small Tungsten
- 26 X 28 X 1000mm (1.024" X 1.108") - For large Tungsten
- 18 X 20 X 1000mm (0.711" X 0.787") - For small cast Lead
- 25 X 27 X 1000mm (0.987" X 1.064") - For large cast Lead
The Carbon tubes are also available in 330mm lengths.