Soldadora de varilla Forney Easy Weld 100ST: configuración y soluciones
Forney Easy Weld 100ST Stick Welder: Settings, Technique and Problems
It comes in a box that weighs less than a bag of dog food. You carry it to the garage with one hand, plug it into the same outlet as your coffee maker, and clamp the ground to a piece of scrap. The first rod sticks. The second one catches, and the arc buzzes through the 10 inch machine like it has no business being this small. That is the Forney Easy Weld 100ST, and for what it is, it works. But you need to know what it can and cannot do before you build anything that matters on it.
The Forney Easy Weld 100ST (model 298) is a 120V inverter stick and DC TIG welder that outputs 90 amps. It weighs 9.65 pounds, runs on standard household power, and uses Easy Start technology to help strike the arc. Forney’s product page describes it as a compact machine designed for portable home, garage, and farm repairs. It is a beginner stick welder, not a production tool.
The short version: if you need to fix a gate, weld a bracket, or practice running beads at home, the Forney 100ST does the job. If you need to weld material thicker than 1/4 inch, run 1/8 inch E7018, or work all day without stopping, you need a bigger machine.
What the Forney 100ST Actually Is
The Forney Easy Weld 100ST is an inverter-based power source, not a transformer. That is why it weighs 10 pounds instead of 90. Inverters switch power electronically, which allows a small, light machine to produce enough current for stick welding.
The specs that matter:
- Input: 120V, standard household outlet
- Output: 10 to 90 amps DC
- Duty cycle: 30 percent at 80 amps (3 minutes of welding out of 10)
- Electrode capacity: up to 1/8 inch (except E7018, which is difficult at this amperage)
- Material range: 16 gauge to 5/16 inch (single pass up to 3/16 inch)
- Weight: 9.65 pounds
- Included: 8 foot electrode holder and 8 foot ground clamp
The machine also has lift-start TIG capability, meaning you can add a TIG torch and argon gas to do DC TIG welding on steel and stainless. It does not have AC output, so it cannot TIG weld aluminum.
The flaw: the included ground clamp is small and the spring is weak. A bad ground connection causes arc instability and sticking rods. Most owners replace the clamp within the first month. Who should skip this machine: anyone welding material thicker than 1/4 inch, anyone who needs to run 1/8 inch E7018 regularly, or anyone doing production work. The 90 amp ceiling and 30 percent duty cycle are real limits.
Settings: Getting the Amperage Right
The Forney 100ST has one knob for amperage. No voltage adjustment, no wire speed, no modes to switch between. You turn the knob, read the number, and weld. Forney’s quick start guide provides these amperage recommendations:
| Rod Diameter | E6011, E6013, E7014 | E7018 | Stainless (E308L, E309) |
|---|---|---|---|
| 1/16 inch | 30 to 40 amps | Not recommended | 20 to 40 amps |
| 5/64 inch | 40 to 60 amps | Not recommended | 30 to 50 amps |
| 3/32 inch | 50 to 70 amps | 70 to 80 amps | 40 to 70 amps |
| 1/8 inch | 80 amps | 80 amps (difficult) | 50 to 80 amps |
Start at the low end of the range and adjust up. If the rod sticks, increase amperage by 5 amps. If the puddle is too fluid or you are blowing through the metal, decrease by 5 amps. The arc should sound like a steady buzz, not a sputter or a roar.
For polarity: most stick rods run on DCEP (electrode positive). The Forney 100ST is a DC machine, so you do not need to worry about AC. Check the rod box for the manufacturer’s polarity recommendation and set your cables accordingly.
Technique: Striking and Maintaining the Arc
Striking an arc with the Forney 100ST is the same as any stick welder. You use a scratch start or a tap start. For scratch start, drag the rod across the metal like striking a match, then lift slightly to establish the arc gap. For tap start, tap the rod straight down and immediately lift to the arc length.
The Easy Start technology helps by boosting current at the moment of strike, which reduces sticking. But the 90 amp ceiling means you have less margin than a 160 or 225 amp machine. On cold metal, the first strike can still stick if you are too slow lifting.
Maintain an arc length roughly equal to the rod diameter. For a 3/32 inch rod, keep the gap at about 3/32 inch. Too close and the rod sticks. Too far and the arc widens, penetration drops, and spatter increases.
Travel speed matters more on a small machine because you cannot compensate with raw amperage. Move too fast and the bead is narrow and underfilled. Move too slow and you pile up metal or burn through on thin stock. Miller Welds’ stick welding technique guide recommends focusing on the sides of the joint on vertical welds and letting the middle fill naturally.
Common Problems and Fixes
Rod keeps sticking: Your amperage is too low, or your ground connection is poor. Increase amperage by 5 to 10 amps. Clean the metal where the ground clamps on. Replace the included ground clamp with a heavier one if the spring is weak.
Arc sputters or sounds rough: The rod may be damp, or the polarity is wrong. Store rods in a sealed container with desiccant. Check that your cables are set for DCEP if the rod requires it.
Weld looks lumpy with slag trapped: Your arc length is too short. You are burying the rod in the puddle and trapping slag. Lift the rod slightly and maintain a consistent gap. Forney’s operating manual describes this as arc distance too short, which causes irregular weld masses with slag contamination.
Weld has poor penetration and excessive spatter: Your arc length is too long. The arc spreads wide and loses focus. Bring the rod closer to the work and maintain a tight gap.
Machine shuts off mid-weld: The thermal overload has tripped. You have exceeded the 30 percent duty cycle at your amperage. Let the machine cool for 5 to 10 minutes. The fan will run during cooling. To avoid this, weld for 3 minutes and rest for 7 at 80 amps.
1/8 inch E7018 is difficult to run: E7018 at 80 amps on a 90 amp machine is at the edge of what the machine can sustain. The arc is unstable because the rod needs more heat than the machine can deliver consistently. If you need to run E7018, use 3/32 inch rods instead, which run well at 70 to 80 amps.
Can You Weld Aluminum With the Forney 100ST
You can, but with limitations. Aluminum stick welding uses E4043 electrodes on DCEP. The Forney 100ST is a DC machine, so it can provide DCEP. However, stick welding aluminum is difficult on any machine, and a 90 amp ceiling makes it harder.
Aluminum conducts heat rapidly, so the puddle moves fast and you cannot see the color change the way you can with steel. You need to preheat thick aluminum to 300 degrees Fahrenheit before welding. The results are messy, with heavy slag that is hard to remove. Hildstrom’s aluminum stick welding project confirms that E4043 electrodes on DCEP work but require fast travel speed and minimal weave.
For anything thinner than 1/8 inch, skip stick and use TIG or MIG with a spool gun. The Forney 100ST cannot TIG weld aluminum because it lacks AC output. For occasional thick aluminum repairs, E4043 rods on the Forney will work, but do not expect clean results.
Should You Buy the Forney 100ST
If your welding consists of home repairs, farm fixes, and learning how to weld with a stick welder, the Forney 100ST is enough machine. It plugs into any outlet, weighs 10 pounds, and runs the rods you need for 3/16 inch steel. It is one of the simplest ways to start stick welding.
If you are weighing MIG welding vs stick welding for your first machine, the Forney 100ST is a stick-only tool. It cannot run a wire feeder, so if you want MIG, you need a different machine. But if you want to learn stick welding on a machine that plugs into any outlet and requires no gas bottle, the Forney 100ST does the job.
If you need to weld thicker material, run E7018 in 1/8 inch, or work for more than a few minutes at a time, spend more for a 160 amp dual voltage machine. The Forney 100ST is a starter tool that will teach you the fundamentals. Once you outgrow it, you will know exactly what you need next.
Frequently Asked Questions
Can the Forney Easy Weld 100ST weld aluminum?
Yes, with E4043 aluminum electrodes on DCEP. It is limited to thick aluminum repairs and produces messy results. The machine cannot TIG weld aluminum because it lacks AC output.
What rods can you run on the Forney 100ST?
The machine handles E6011, E6013, E7014, and stainless rods like E308L up to 1/8 inch. E7018 in 3/32 inch runs well at 70 to 80 amps. E7018 in 1/8 inch is difficult because the 90 amp output is not enough for sustained runs.
What power outlet does the Forney 100ST need?
Any standard 120V household outlet. It draws less than 20 amps at full output, so it works on a 15 amp circuit, though a 20 amp circuit is better for sustained welding at high amperage.
What is the duty cycle on the Forney 100ST?
30 percent at 80 amps, meaning 3 minutes of welding out of every 10. At lower amperage, the duty cycle increases. At 50 amps, you can weld longer before the thermal overload trips.
Can you TIG weld with the Forney 100ST?
Yes, it has lift-start TIG capability for DC TIG on steel and stainless steel. You need a TIG torch, argon gas, and a regulator, which are not included. It cannot AC TIG weld aluminum.
Is the Forney 100ST good for beginners?
Yes. The one-knob amperage control, 120V input, and Easy Start technology make it one of the simplest stick welders to set up and use. The limitation is the 90 amp output, which caps the material thickness and rod sizes you can run.
What is the difference between the Forney 100ST model 298 and 100 ST-i model 297?
The model 298 is the original 90 amp version. The model 297 (100 ST-i) is the updated version with up to 100 amps output, an LCD display, and arc force control. Both run on 120V and handle similar material ranges. The 297 adds more precise amperage control and a slightly higher output.
