Doubleumc

You can get an empty blue barrel by reclaiming a large box of trash.

This is no longer necessary. The steam machine recipe (and all other recipes) now accept the craftable metal barrel from the "Make Metal Barrel" recipe.

If you're referring to the "Make Salt Powder" recipe, it accepts the Hydrocraft version of mortar and pestle (crafted with two stones) but not the vanilla version. Not sure if that's intended.

I took a peek at the other recipes and it seems "Make Ammonal" and "Build Professional Lab" also look for the old barrels. On that note "Make Bone Powder" accepts the Hydrocraft version of the mortar and pestle, "HCMortarandpestle", but not the vanilla version, "MortarPestle".

Also logged in w/r/t Metal Barrel problems. Looks like the Steam Machine wants a "HCEmptybarrelmetal", but the barrel object is known as "HCMetalbarrel".