Welding

[BrentD]

Ok, so I haven't touched a welder since back in high-school in 1995 and that was an old 1950's or older tombstone Lincoln. Back then I was taking an Ag class thinking that would be the easiest way to weld. Unfortunately, school budgets being what they are, the class was held in an old maintenance garage with terrible lighting and the only welding helmets we had were probably shade 15.

Back then I was so nervous and blind through the helmet that I stuck the rod to the table more often than I was able to successfully strike an arc, and when I finally got the arc striking down I'd end up welding my workpiece to the table because I absolutely could not see when I got to the end. And yet, somehow I managed to pass....

Well, fast forward to the present. In one of those bizarre deals only Harbor Freight can come up with I got a welder for 25% off, then was able to use another 15% off coupon. I ended up with their 110 Amp 220V MIG welder for around $150. That was Last Christmas. Finally got around to using it for the first time today. Needed to make a new alternator bracket to fit a Delco 12SI alternator to my Geo Tracker.

Spent about 30 minutes doing test welds on the same thickness metal I'd be using for the bracket. Once I got a good understanding of how the MIG plasma flame melts the metal and the wire I was able to get decent welds fairly quickly. My auto-darkening helmet is an absolute luxury compared to those old flip-down Shade 15's from back in school. After I got the hang of controlling the welder I cut and drilled all the pieces for my bracket, cleaned them up good and then proceeded to weld my first actual usable item.

I'm sure it won't win any awards for nice looking welds, but it's holding together even after some fairly hefty whacks with the sledge hammer.

I do have a few questions after this first experience though... I had trouble controlling my wire speed. Seemed like it was either too fast or too slow. I was welding 1/4" plate, Mostly Fillet welds. At one spot near the end of one of the welds it looked like the weld bead sort of took a chunk out of the metal, so I turned my amps down and raised the wire speed. The big issue I ran into with most of my welds is that the bead is pretty thick. Looks like somebody over-did it with a glue gun. From the edges you can see that the bead is penetrating into the sufficiently though. I thought turning down the wire speed a little would give me a better looking weld without piling up so much metal on the bead, but it just gave me a sputtery weld that was more like a rapid series of arc strikes. I eventually just turned the speed back up and finished my job with the ugly welds. At least I know they'll hold.

Any suggestions for getting better control of the machine (apart from getting a better machine with dials for current control instead of switches)?

 

[framer]

Using flux core wire? If so hard to get nice welds. 75/25 gas looks much
better.And you are welding 1/4 plate that would be max out on most 110 units.Good luck Framer

 

[dbdartman]

With fixed voltages you use wire speed & torch speed (technique) to control the puddle. Sounds like you wanted the torch to run hotter so you should have moved faster to counter the heat.

A good weld sounds like bacon sizzling in the pan.

When all else fails, read the instructions! My welder has a guide on the lid: Material thickness, voltage & wire speed settings for solid (c25) & flux core wire. Setting the machine to their recommendations before starting means minor wire speed adjustments at most.

 

[RWolf]

Wire size has a big factor on welding. Welding 1/4 in. needs to have at least a .035 wire. You "can" get decent welds with flux core and in some situations it's better than gas. I've made the mistake on using to small of wire and my welds looked like crap and I didn't have any penetration.

 

[BrentD]

Should have mentioned that I was using .35 wire. I totally get the bacon sizzling thing. I spent a whole 6-weeks trying to get arc welding down back in high-school and never quite got past being startled every time the arc struck. Thinking about that I was really nervous before pulling that trigger the first time today, but was pleasantly surprised by the nice steady hiss with just a bit of popping.

Also, I'm using solid wire with 100% argon. When I bought the machine I was planning on building an aluminum frame for a pontoon boat so I got the pure argon to weld aluminum.

The sticker in my welder is actually in the wire compartment. I was going by the general recommended settings for 1/4" in there. That's supposed to be about the upper limit of what the welder will weld, even though I did manage to burn a hole through one of my test pieces of 1/4" with the welder at full power. I think everybody is right about my speed though. I think I was probably trying to remember what I was taught in high school and probably moving the torch too slow and letting the metal build up. I probably didn't do too bad for a first timer. I'll try to get some pics of the bracket tomorrow, just don't laugh too hard when you see them.

 

[AKwelder]

think of welding this way. the voltage controls the profile (flat or not) of the weld, the wire speed simple put controls the amperage. The faster the wire reaches the work, the more amperage the machine uses to melt the wire. As the wire speed and amperage increase the voltage required to produce the same profile increases.

to set your wire speed here are the two main items to remember, if it is to slow it burns back to the tip, to fast and it hits the work and jerks. If you turn the wire speed up or down more than a small amount you will need to adjust your voltage.

The pure argon will work, I would have bought 75/25 for most welding and CO2 for junk iron. 100% argon cost a lot more than 75/25, and until you are ready to tackle your aluminum you don't need it. Also if you have a gas cylinder, most welding stores will let you exchange it for cylinders with other gases. I turned in my argon when it was empty for Helium to fill a bunch of balloons for my buddies wedding.

 

[smfcpacfp]

I concur with everything AKwelder said. Using pure argon with steel is not recommended and usually requires less voltage, and it sometimes leaves a hummpy, skinny weld with some undercutting. I can't imagine what caused the problem near the end unless it was "arc blow", or a base metal imperfection. I sometimes put a piece of scrap metal beyond the end of the welded piece to avoid arc blow ( i.e., the weld really ends on the scrap).

I assume when you said you turned down the amperage, you meant you turned down the voltage, but it seems like you have the concept down. If I had a hummpy weld I would have probably first turned up the voltage, and then perhaps down the wire speed, however. I think your problem is that the machine doesn't allow fine enough adjustments to get the perfect looking weld. Once you get the settings just right, the weld will look great and be strong. Switches (high, low voltage) just won't do that. You could grind the weld a bit if it looks real ugly, and then paint it.

I just bought a Millermatic 211 this last week with a Spoolgun for soft metals (i.e., soft wire). It is infinitely flexible and really fantastic, but the whole shebang (filled tank, cart, out the door) was 10 times the cost of yours, unfortunately.

 

[BrentD]

I assume when you said you turned down the amperage, you meant you turned down the voltage, but it seems like you have the concept down. If I had a hummpy weld I would have probably first turned up the voltage, and then perhaps down the wire speed, however. I think your problem is that the machine doesn't allow fine enough adjustments to get the perfect looking weld. Once you get the settings just right, the weld will look great and be strong. Switches (high, low voltage) just won't do that. You could grind the weld a bit if it looks real ugly, and then paint it.

I was mainly going by the chart on the front of the welder. It has 2 switches, One for Min and Max, the other for range 1 or 2. The settings go min 1, min 2, max 1, max 2. The chart shows a voltage increase for each step, but also an increase in available current. The change in available current seemed to be the more significant change on the chart, so that's what I thought I was changing. The voltage change is rather slight. From Min1 to Min2 the voltage only goes from 16 to 18 volts, but the current goes from around 20 amps to around 40 amps. (If I remember right the current steps are 20, 40, 65, 110).

 

[sizzami]

.035 wire is too big for your machine I have 3 250 amp lincolns on my floor and unless we are doing structural steel we run .030
try using 5% helium 70% carbon dioxide 25% argon mix this will get more heat aout of your little machine mig isnt really accurate in this case since helium is not inert and will cause the wire to burn hotter.
heat is the problem trust me , a simple way to prove it is this: set the welder up as you were .start a bead slowly move your nozzle closer to the work ,does performance improve ? it should , think of the wire like a resistor longer resistor = more energy to melt it
also the bacon thing is kinda half right it should sound like bacon frying without the silences between it should be a sizzle with a slight little groan the more uniform the better , remember with welding usually if it looks good it is good

 

[Knight]

I was mainly going by the chart on the front of the welder. It has 2 switches, One for Min and Max, the other for range 1 or 2. The settings go min 1, min 2, max 1, max 2. The chart shows a voltage increase for each step, but also an increase in available current. The change in available current seemed to be the more significant change on the chart, so that's what I thought I was changing. The voltage change is rather slight. From Min1 to Min2 the voltage only goes from 16 to 18 volts, but the current goes from around 20 amps to around 40 amps. (If I remember right the current steps are 20, 40, 65, 110).

A good way to set wire feed speed is to place a scrap piece very close to the welder so you can easily reach the control knobs. Then weld and adjust wire speed until it sounds just right. The label settings are just a close estimate.