Intro: Monster Soldering Gun
Are you tired of having a dinky safe soldering gun that only puts out a measly 250 watts of power? Are you tired of your puny 40 watt soldering station taking forever to heat up? How about upgrading to a monster 2250 watt soldering gun that heats up in 2 seconds, gets red hot in about 15, and a very real possibility of melting if you hold the trigger for more than a minute. If yes, then for about $45 worth of easily available parts, you can build your own monster soldering gun.
Step 1: Parts
-A 4500 watt 240 volt water heater element
-A suitable 120 volt polarized power cord
-a metal conduit box with 1/2" threaded openings
-a 1"x3/4"x1" NPT steel pipe tee
-a 3/4"x1/2" steel pipe bushing
-2 3/8" NM cable clamps
-a 1/2" steel pipe nipple
-an SPST momentary button switch rated for at least 6 amps at 120 volts
-2 fork crimp connectors
-2 ring crimp connectors
-heat shrink tubing
For those of you who live outside of North America, I do not know your standard conduit box, pipe, and element sizes, or electrical standards, so if you attempt this project, you will have to figure out what parts will work. I am sorry. Even if I did provide metric conversions, they may not apply to the parts you can locally source.
Step 2: Tools
-A screwdriver, my particular box, clamp, and element had Phillips and flat head screws, yours may be different
-Your tool(s) of choice for cutting, stripping, and crimping wire. I used a pair of line mans pliers and crimping pliers.
-A scriber or marker
-A combination square, ruler, or tape measure.
-A center punch, I used an automatic center punch.
-A pair of channellock pliers.
-An adjustable wrench, a pipe wrench, or a second pair of channellocks.
-A lighter, heatgun, or torch.
-A drill, if you have access to a drill press or mill, use that.
-A 1/2" drill bit.
-A 7/8" drill bit, I used a step bit.
-A 1/8" drill bit or #3 center drill.
-A deburring tool or small round file(not shown).
Step 3: Layout
-Find the center of the front plate, and mark a spot about 1&1/4" from the center of the screw.
-On the back side, find the center of the box and mark a spot 1&1/2" from the very end of the threaded portion.
-Center punch the spots you marked.
Step 4: Pre-drilling
With a 1/8" drill bit or #3 center drill, pre drill the spots you marked on the front and back.
Step 5: Drilling
Drill a 1/2" hole on the front cover, then remove it, there will be a rubber membrane underneath, you can discard this, make sure you do not lose the screws. Then flip the box over and drill a 7/8" hole in the back. I used a vise for drilling, and you should too, I just took the picture in a better lit spot.
Step 6: Deburring
With a deburring tool or small round file, deburr the holes, be careful not to enlarge them.
Step 7: Box Assembly
Screw one NM cable clamp into the 7/8" hole on the back, and the other in the threaded hole opposite the drilled side. Then install the button switch in the 1/2" hole on the front plate. Make sure the switch body is in a vertical position so that it will fit properly into the box.
Step 8: Assembly
Screw the 1/2" pipe nipple into the top of the conduit box. Next screw the 3/4"x1/2" bushing into the pipe tee. Then screw the tee and bushing onto the box. Finally, screw the heater element into the pipe tee using a pair of channellocks or an element wrench. Make sure the rubber gasket the comes with the element is used.
Step 9: Finished Assembly
This is what it should look like up to this point.
Step 10: Cord
Separate the wires from the end to roughly 12".
Step 11: Cutting the Cord
Lay the wire on top of the gun and cut the hot wire, not the neutral wire roughly where the switch will be. The hot side is the skinny prong, and the wire without ridges.
Step 12: Stripping
Strip both ends of the short piece you cut, and the ends of the cord. Only strip about 1/4" and tightly twist the ends.
Step 13: Crimping
Crimp a ring connector to the long end of the cord, and a spade connector on the short end. On the short piece crimp a ring connector on one end, and a fork connector on the other. Then remove the insulation from the ring connectors, the easiest way to do this is to crimp the plastic shroud in a couple different directions, slide it down the wire, and carefully cut it off with a pair of diagonal cutters.
Step 14: Wiring the Switch
Fish the cord through the bottom of the box. Then put a piece of heat shrink tubing on the wire ends with fork connectors. Connect the fork connectors to the switch terminals and heat shrink the connections.
Step 15: Closing the Box
Fish the ends of the wires out the back of the box. Then screw the box shut.
Step 16: Connecting the Element
Connect the ring connectors to the screw terminals on the element. Then bend the connectors back towards yourself.
Step 17: Finishing Up
Finally, screw down the NM cable clamps. Be careful not to go through the wire insulation. If you'd like, cut the protruding ends off the screws.
Step 18: Usage Technique
This gun is incredibly dangerous and heats up almost instantly. You should not hold the trigger down for more than a few seconds at a time. The element cools down very slowly, so you do not need to hold the trigger down. The element doesn't even need to get red hot to solder. Be careful not to hold the trigger down for very long, or the element could melt. A good rule of thumb is to hold the trigger until the element barely turns a dull red, and when it goes back to its normal color, pull the trigger again. But you can experiment and figure out your own techniques. This gun has many hazards. It gets very hot, and when the trigger is pulled, there are exposed 120 volt contacts on the back. Have fun!