I am looking for an AWS or PSNS instruction, if one exists, that specifies the required/allowed cup size when using 1/8" Tungsten while welding aluminum. I am trying to change an instruction for performing structural maintinence on LCACs. Our procedure calls for the usage of a 1/2" cup with a gas lense (a #8) while using 1/8" Tungsten. This makes our job incredibly hard while doing repairs out of position and in confined spaces and inhibits seeing the puddle. But when using a #5 cup our job becomes much, much easier. Any help or insight would be greatly appreciated.