Factorio Forums

Currently, setting "molten iron" (the liquid) as recipe does not select "molten iron" (the recipe)-- it selects "molten iron from lava" instead. Same for copper.

Expected behavior:
When sending a "molten iron" (the liquid) signal to a forge, the "Molten iron (Recipe)" should be selected.
When sending a "molten copper" (the liquid) signal to a forge, the "Molten copper (Recipe)" should be selected.

This is especially impactful because this is primarily encountered on space platforms and takes a lot of extra circuits to fix.
The current behavior is never desirable in my opinion (because regulating lava processing on Vulcanus is pretty much pointless anyway, while regulating non-lava ore smelting makes sense both in space and on other planets).

It is also a bug in my opinion because "Set recipe" should map to the recipe with the same name when possible and not to something else.

See example: This is a loosely related bug that is going to be fixed (similar issue for crushers):
viewtopic.php?f=30&t=119690

In case someone else runs into this problem the important part is to set the recipe to the Molten Iron or Copper inside the Intermediate products tab and not the fluids tab.

To get the a storage tank to output the correct thing directly, just add an arithmetic combinator multiplying the fluid by one, and choosing the intermediate product as output like shown in the picture. Requires an arithmetic combinator per fluid, so just two.