Sorry but it would be better to show people how to weld properly and avoid burning holes in the first place. That is a bit like showing people how to crash when learning to drive. Having watched the footage it is apparent to me the welding in both cases is not very fluid. I put my tacks a lot closer together this pre-heats the ally ready for the next tack, these are done in quick succession then the weld is laid with a fluid pass from one end to the other. You can see this here...
http://www.youtube.com/watch?v=IGElSHzm0q8
David