Why doesn't someone offer plans for a natural gas forge? I have a commercial building so bigger lines coming into the shop. The problem with propane is moving them outside overtime I'm done using them. I talked with my city inspector and he won't allow a large refillable external propane tank which would be fine with me, but he said since natural gas is available propane isn't an option. Even the midsize tanks being outside might be a possibility, but moving them to fill is a pita. I keep reading of natural gas forges that work, but no-one shares their plans. Help a brother out.