Introduction: Water and Salt Welder

About: DIYer and enthusiast of everything. I have been tinkering with a variety of things since my childhood, from simple electronics to workshop and audiovisual.
Hello fellow 'iblers! Today i'm going to teach you, how to build a Welder with plain Water and Salt, yes you did read it right! WATER AND SALT! And there is even Historical reference to this kind of welder.
Check out the Video:
Despite from the Video name, I'm not Mexican and I don't speak Spanish!

Step 1: High Amperage! Careful Is Just the Beginning!

This project uses High Amperage and High Voltage and it's mostly lethal if not handed carefully, allways wear gloves and shoes, don't operate exposed parts or not securely insulated components, If you need to change the positions of the cables inside the water, unplug it first. Use all the recommended welding equipment when working on this project incluing: Welding Glasses or Mask, Leather Gloves, Leather clothes and an insulated surface. Don't forget to be dry (always dry your hands if you change anything on the water).

Step 2: Materials

10m of AWG #7 (10mm) wire
20L of water
1Kg of salt
Electrode pliers
Earth clamp
6013 or 6011 Welding rods
Wire Cutter
Screw driver

McGayver Version:
10m of AWG #5 - #7
20L of water
1Kg of salt
2 Insulated Pliers
6013 Welding rods

Step 3: Cut the Wires

OK, first we are going to need 3 pieces of wire, take the 10m piece and cut it in half, next take one of these half's and cut in half again.

Now we got 3 pieces of wire:
1 5m piece
2 2,5m piece

Take the 5m piece, scrape about 1,5cm on each side of the cable, it will be used as the ground wire.
Take the 2,5m cable and scrape 1,5cm on one end and 20cm on the other end, these will be our positive wire.

Step 4: Install the Contacts

Now Install the Electrodes holder on the 1,5cm end of the 2,5m cable, and the earth clamp on one of the 1,5cm end of the 5m cable.

Step 5: All Goes in the Water!

Fill the 20l gallon with around 15l of water, put the 20cm end of the 2,5m cables in the water and put something on the bottom to hold them submerged and straight. Pour around 500g to 800g of salt on the water.

The salty water will work as a variable resistor, powering the AMPs up based on Electrolysis.

Step 6: Plug and Arc

To turn the power on, Attach the 5m cable on the neutral line of your wall plug and the 2,5cm cable on the Positive line, DON'T PUT THEM AS YOU WISH, YOU MUST KNOW WHICH ONE IS THE HOT WIRE AND WHICH ONE IS THE GROUND WIRE. Put the 6013 electrode on the electrodes holder and try striking an arc, if the amps are too low, put the two cables nearer inside the water, if the amps are too high, space them from one another. DON'T FORGET TO UNPLUG THE WIRES BEFORE ADJUSTING THE CABLES.

Step 7: Why It Works?

OK, let's go to the Science of the thing!

Take a look at the table (fig. 1), as you see, water is very resistant, so plain water will not allow any current being draw, the objective here is to lower the resistance of water until you can draw current from it, and as you see, from the gaps between the wires, it varies on cm, so as much as you take them apart, more resistance is added, if you put them together less resistance is added.

So, the variables we are working with here are V (Voltage), I (Current), R (Resistance in Ohms) and D (Distance in cm).

To measure I (Current), to find out how much amps we are drawing, we gonna divide V (Voltage) to R (Resistance in Ohms), just like this:


We know the value of V that is begin used, in this case 110v, but the value of R is based on distance and salinity, so we can define Rd, which is equal to Rs (Resistance from the salinity table (fig.1)) times D (distance in cm).

We end up with something like this:




If we substitute for the values we know for, say as salty as sea water in open sea 10cm apart, we will end up with something like this:






That ends up like:


So, for this situation we can draw 0,5 amps from this circuit. Following this same formula for 1cm apart, we end up with a maximum theoretical value of 5,5 amps. If the voltage used was 220v, then we end up with a maximum draw of 11 amps.

My setup tripped the breakers twice during the development of this project, and my breakers are rated for 10 amps, so my water was overly saturated with salt plus the fact that the wires where submerged to the bottom of the solution, which is denser and saltier. We can even say that the resistance varied based on depth and end up with a gradient of resistance that sums up to a average resistance, plus the resistance of the wires themselves.

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