Describe the bug
You can convert your PTFE(or PBI or Steel) to tin with following recipes:

Versions
GTCEu: 2.3.4

Setup
dev env

There is no real good way to get around this without introducing a system to keep track of what material components were made of. The issue is, this system was wildly unpopular in GT5u, because it prevented things from stacking, threw off recipes, and other things, as the system was implemented through NBT.

I personally am fine with the ability to transmute materials, in this case, as it is going from higher tier -> lower tier material, and implementing a system to keep track of the materials that the item is made from would cause annoyances to players.

I think we can fix this by simply removing the arc furnace and macerator recipes for the spray can.