RAZOR™ 200 AC/DC: DC TIG Welding Setup Guide

June 11, 2020

G’day and welcome back to UNIMIG. Today I’m going to show you how to set up for TIG welding mild steel using DC for the RAZOR 200 AC/DC.

Please note that at first this machine can seem quite complex and takes time to get used to. However, this guide will give you a greater understanding of the specifics of this machine and how it operates.

Today we will be using our prefered settings for both DC and DC pulse for 3mm thick Mild Steel as well as give you a basic guide if welding other thicknesses of Mild Steel.

First, let’s plug our machine into our 15 amp plug into our wall socket and organize the suitable PPE.

Step 1: Polarity

We are going to start off with DC Tig so our earth lead goes into the positive panel-mount socket, our torch goes into the negative panel-mount socket, our amphenol plug goes into our amphenol socket and our gas hose connects to the gas connection on the front panel of our machine.

Step 2: Gas connection

It’s now time to connect our gas hose to the gas inlet on the back of our machine if using a regular gas hose make sure you crimp it tight. using a hose clamp. Next, you will need to insert the regulator tail into the other end of the gas hose, again crimping using a hose clamp. This is the flowmeter regulator we are using, now we connect our flow meter regulator to our gas bottle and tighten using a spanner.

This is pure argon gas ideal for tig welding aluminium. The next step is to attach the other end of the gas hose to the regulator and tighten once again with a spanner.

Step 3: Basic setup

To start, Make sure your selector switch is turned to DC. You can then choose between 2t, 4t or spot. 2T means you need to retain pressure on the trigger while welding, 4t, which means after you press the trigger the arc will continue on its own until the trigger is pressed again. And finally spot, which will give you consecutive and evenly timed tacks. We will be using 2t for the purpose of this demonstration.

Step 4: Weld Cycle Parameters

Now we will go in-depth of each setting for DC, as well as setting to our preference for TIG welding 3mm thick Mild Steel. One reason you would use DC over DC pulse is to get deeper penetration on thicker materials, generally increased by 30 amps for every millimetre.

Part 1: Pre Gas

Pre gas is the gas that shields the area and the tungsten before welding so the start of the weld doesn’t get exposed to the atmosphere. If you turn it up pre gas more gas flows out for a longer period of time and if you turn it down it flows out for a lesser period of time.

Part 2: Start amperage

Start amps allow for a lower or higher amperage startup. If you turn it up, it will start the arc at a higher amperage, best suited for thicker materials and if you turn it down it starts at a lower temperature, which is best suited for thinner materials.

Part 3: Up-slope

Up-slope dictates the time between the start-up amps and the peak amps. If you turn it up, it will increase the time it will take for the amps to climb to the peak amps, this is suited for thinner materials to minimise burning away of edges and if you turn it down it will decrease the time for the amps to climb to the peak amps, which is suited for thicker materials.

Part 4: Peak amperage

Peak amp is the amperage at which you will be welding at once the current climbs up from the start amp. If you turn it up the amps will be higher and if you turn it down your amps will be lower.

Part 5: Downslope

Downslope dictates the time between the peak amps and finish amps. This will taper the arc to prevent crater holes and cracks at the end of the weld.

Part 6: Finish amps

The Finish amps are the final amps that the arc will get to after the amps have decreased before the arc turns off. If you turn it up it will be a hotter finish, suited for thicker materials and if you turn it down it will be a cooler finish, suited for thinner materials.

Part 7 post gas

Post gas is the gas that flows for a set time after the arc has turned off to shield and cool the tungsten as well as the weld. If you turn it up it flows for longer, reducing pinholes and craters and cooling down the tungsten and if you turn it down it flows for a shorter period of time suited for thinner welds.

Part 8: Torch setup

To set up the t2 torch that comes with the machine, you will need these consumables. A head gasket, a heat zone isolator, a gas lens and collet, a backcap, a shroud and a tungsten, which we will go more into depth in the next section. To put them on the T2 torch you will need to slide on the head gasket, screw on the heat zone isolator, push in the gas lens and collet, screw on back cap, slide in the tungsten and push on the shroud.

You can also set up remote mode for use with the optional foot control or the torch control. To do this hold the button for 5 seconds or until the machine beeps and the green light comes on, Then you are able to change the amps using the optional foot control or the torch amperage control.

Part 9: Tungsten electrode

Firstly you will need to choose the thickness of the tungsten electrode you are using, we supply 4 types of electrodes for this machine, the grey tipped ceriated, the white-tipped zirconiated, the purple-tipped E3 and the gold-tipped lanthanated. We will be using the gold-tipped lanthanated as it is more versatile and has better arc characteristics.

Step 5: Tig Welding

Now that you have set your parameters, it’s time to turn your gas on to around 8 to 10 L per minute and attach the earth clamp to your workpiece. You are now ready to weld.


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