The Solderer is a block that is used to craft several items from the mod.
The Solderer is not sided. You can insert from any side and it'll automatically put the items in the right slot.
In RS for MC 1.10.2 it is sided: bottom side for output slot and other sides for input slots.
When the Solderer is running, smoke particles are visible.
Use of JEI (Just Enough Items) is (highly) recommended to see the recipes for the Solderer.