ApocalypsePal

I'm having trouble making a cement mixer. I started as mechanic. I found the schematic for the mixer. I looked at the perk list and it was a red check mark. Tip says it requires science crafting 2, Mining Tools 20, No Laborer Class. I gained a few levels to get science crafting 2. My mining tools is at 43. The check mark is white now in the perk list, but I still can't make the mixer. The only option on the recipe is Perk <w>. I've tried from inventory and from a workbench with both wrench and hammer in it. Edit: I think I see now that it needs a metal workbench and a welding torch. *facepalm*