Some time ago I needed an 100 w dummy load for of air transmitter testing (it's bad to put 100 w on an antenna and whistle ).
What beter use for 42, 2k1 (2100 ohm) resistors in parallel :)
The box was done with an paint container after some cleaning. Originaly the idea was to put engine oil inside for termal dissipation but if I don't transmit for more than an minute theres no overheating problem.
The resistors were placed in an PCB board all lined up and the other end conected by an wire mesh.
The photos show the final product.