The Soldering Iron can be used to attach certain Vacuum Tubes (Tin Electron Tube, Copper Electron Tube, Bronze Electron Tube, or Iron Electron Tube), to Circuit Boards and to remove Circuit Boards from Electrical Engines. Without modification, the Electrical Engine outputs 2 MJ/t. It can be upgraded to produce a maximum of 10 MJ/t (by attaching an Enhanced Circuit Board with two Bronze Electron Tubes); note that the Electrical Engine will also draw 36 EU/t, six times the normal EU consumption. Breaking an Electrical Engine without removing the board first with this tool will destroy the Circuit Board.
To attach tubes with the Soldering Iron, put it in your hotbar and right click towards any empty area/block without a right click interface. This will bring up the Soldering Iron's GUI. It is important to note that you must place ALL the tubes you wish to attach on the left hand side before putting the circuit board on the right. Placing the board in the Iron's interface will fuse the tube(s) to it permanently! Do not stack tubes if you are trying to use more than one of the same type for a single board, place only one in each slot on the left. The Circuit Board will only take the Electron Tubes which are in the top slots of the Soldering Iron's GUI; for example, if using a Medium Circuit Board, the Circuit Board will only take tubes in the top two slots and the bottom two will be ignored whether they have tubes or not, as the Medium Circuit Board can only hold two tubes.
A Large Circuit Board can hold up to three tubes, a Medium Circuit Board can hold two tubes, and a Small Circuit Board can hold one tube. Removing boards from engines uses durability on this tool, but crafting boards does not. Since the Soldering Iron only has six uses, it is advisable to think twice before adding a Circuit Board to an Electrical Engine, as they can only be removed safely with a Soldering Iron. It is also wise to think twice before soldering Electron Tubes to a Circuit Board, as any Circuit Board that has had Electron Tubes soldered to it cannot have these tubes removed.
|Type of tube||Effect (Max stack)||Change in input EU||Change in output MJ||MJ:EU ratio (Normal 2:6 = 1:3)|
|Copper||Choke(1)||-2 EU/t||-1 MJ/t||1:4 (Worst)|
|Tin||Boost I(2)||+7 EU/t||+2 MJ/t||4:13|
|Bronze||Boost II(2)||+15 EU/t||+4 MJ/t||6:21 = 2:7|
|Iron||Efficiency(1)||-1 EU/t||No change||2:5 (Best)|
Golden Electron Tubes and Diamantine Electron Tubes are currently used only as crafting components and cannot be soldered to a Circuit Board to upgrade an Electrical Engine. The max stack is the limit for how many of that specific type of tube can be on a single circuit board irrespective of the circuit board's maximum tube capacity.