Fredan writes –

I have found instructions on how to convert kegs, using reciprocating saws, grinder, and plasma cutters. But in my experience, kegs which are ground or sawed generally produce uneven or oval openings. Plasma cutters on the other hand produce outstanding openings; unfortunately I don’t have many friends who have them at their disposal. So I came up with a different way of cutting the opening. In essence, I have created a hand turned lathe for a keg. It cost me around 30 dollars, but depending on your own personal inventory of tools, the cost may be higher or lower. The project took about 3 hours which included the construction, cutting out the opening and smooth out the edges.