Welding Tips and Tricks

Today I did a fillet weld with TIG for practice. I was welding 1/8" carbon steel with C25 and .035" wire. Because scale builds up on the opposite side, I decided to MIG the back instead of using TIG. I figured it was easier to clean the metal back to MIG standards than TIG, and I needed the practice.

The MIG spattered like crazy, and the weld was very lumpy. At the end of the weld, I got a spoon-shaped depression, as if the gas had blown the hot metal out. This happened with several other beads I laid down. I fiddled with the gas, voltage, and wire speed, and things worked better when I increased the voltage, slowed down the wire, and took the gas from 35 cfm to about 22.

I started out using the settings recommended on the little chart on the welder (PowerMIG 180C), but it looks like they're not right. The gas, in particular, was way high. Am I the only one who finds the chart useless?

I have no idea what the settings on the little dials actually mean. They don't correspond to volts or feet per minute.

On the up side, MIG seems much easier to control after struggling with TIG. I guess TIG improves your MIG skills.

Yeah, they're pretty useless. Ballpark at best.

For the WFS its best to just chart the settings by running it out for 6 seconds, measure, and multiply by 10. For voltage, see if you can get someone to read it across the terminals by the gun block while you weld with a multi-meter.

Then you can set according to the wire manufacturers specs, which are still ballpark, but real numbers and usually tested.

edit: You can also wind the wire back in each time instead of clipping it off and wasting many feet of wire.

A good way to learn about mig settings is just playing with settings. A lot of spatter-Adjust your wire feed speed both ways and see what happens and find a sweet spot and then take a sharpie and right it on the welder or put a peice of paper on it.

Chips,

The crater at the end always happens, and is solved by a technique commonly called "buttoning off". When you stop, pause for about a full second without moving the gun, then hit the trigger again for about a full second to fill the crater. You want the metal to solidify (the first second), but not cool below red heat. The next second of welding without moving the gun fills in the crater and prevents the weak spot/cold crack that could occur if you wait too long to fill it.

I say "full second", but the timing depends on the material thickness and wire size. Experiment, and you'll sort out how long to pause and how long to button off.

Steve S

Have you ever used that MIG machine to weld flux core wire? I'm wondering if this might be a polarity issue.

Well this is funny. It turned out the gun cable was loose, so I wasn't getting gas. I don't know why the welds looked lumpy instead of porous, but there you go. I figured it out when I Googled to find out why there was brown powder all around the beads. Usually when I forget to turn the gas on, the resulting weld looks like a sponge.

I got the welder tightened up and started over. I got a much better bead, but still some powder. Cranked the gas up to 35 and reduced it somewhat, but it seems like it won't go away.

I came up with a way to test the gas flow. I put the end of the torch in a glass of water and let fly.

Anyway, I feel a whole lot better. I ran two nice long lap beads, and they're really good compared to my usual mess.

I have never used flux core wire.

Interesting note: I felt little things hitting my legs while I welded. I figured it was bits of spatter. It turns out UV light attracts winged ants. Apparently a swarm has moved in. One ended up on the weld.

For most short circuit mig I run around 20 CFH at the most

You must know the answer to this question, then. Am I supposed to be getting all that brown residue?

Chips O'Toole wrote:You must know the answer to this question, then. Am I supposed to be getting all that brown residue?

The only time I have ever had that brown soot is when I tried spray transfer on dirty metal with piss poor settings and the wrong gas mixture. For short circuit I haven't had the brown stuff before though.

Hmm. Not really. Try disengaging the drive wheel and checking how much gas flow you have when its running. A lot of regulators spike quickly then drop into the running range.

Maybe its just frivolous, but for hard wire mig, I like a minimum of 25 up to 35. The gas shouldn't blow away the molten pool unless its some kind of crazy high.

Chips O'Toole wrote:You must know the answer to this question, then. Am I supposed to be getting all that brown residue?

Yes and no.

exnailpounder wrote:

Chips O'Toole wrote:You must know the answer to this question, then. Am I supposed to be getting all that brown residue?

Yes and no.

Why not explain it Jeff. Why yes and why no...

Farmwelding wrote:

exnailpounder wrote:

Chips O'Toole wrote:You must know the answer to this question, then. Am I supposed to be getting all that brown residue?

Yes and no.

Why not explain it Jeff. Why yes and why no...

I can't explain it because I have a bad hangover...what day is this?

A hangover and you are up at 6:00 and on the forum? wow this man needs a beer or something. Oh and its Monday...but for a second I thought it was Wednesday and then I thought Tuesday and I dont have a hangover so...

exnailpounder wrote:

Chips O'Toole wrote:You must know the answer to this question, then. Am I supposed to be getting all that brown residue?

Yes and no.

Agreed

Given the choices, I choose "yes."

Chips O'Toole wrote:Given the choices, I choose "yes."

Sorry man, you don't get a vote because you're not supposed to be getting all that brown stuff

MinnesotaDave wrote:

Chips O'Toole wrote:Given the choices, I choose "yes."

Sorry man, you don't get a vote because you're not supposed to be getting all that brown stuff

Right! A little smoke is normal sometimes but not the whole weld. I looked closer at the pic and you even have soot on the table . Gas trouble somehow/somewhere. Is your nozzle and contact tip full of spatter? It builds up really quickly if you don't use nozzle gel and will cut your gas flow down considerably.

If the bugs were coming in was there a breeze blowing around as well?

Before I did that weld, I took the nozzle apart and cleaned a ton of brown crap out of it.

Chips O'Toole wrote:Before I did that weld, I took the nozzle apart and cleaned a ton of brown crap out of it.

No telling then. You need to look for gas problems. You're getting some shielding otherwise your weld would be porous but you must be drawing in air or something. You're using 75/25?(C25)

I believe I loosened the cable connection when I changed the spool from stainless to steel. That would explain why I lost gas. But I tightened it up and cleaned the nozzle before making the long weld in the photo, which was surrounded by brown dust.

It's C25.

I don't suppose wire lube would make that stuff? I have two felt things on the feed mechanism, lubing the wire.

I have a couple of CO2 tanks from my brewing days sitting around. I could try a pure CO2 weld and see what happens.

I'm really happy about the weld, though. It's a big improvement over recent efforts, and there's a much nicer one on the other side of that piece of scrap.

Yes that lube can do stuff like that. I used to use the pads but just dry.

Poland308 wrote:Yes that lube can do stuff like that. I used to use the pads but just dry.

Agreed. I've used the lube only rarely, and it only takes a couple drops. We had one guy at work who would saturate the pad like he was greasing the wire rope on a crane, and couldn't understand why his welds were crappy. I now never use the lube. It's less hassle to replace the liner occasionally.

Steve S

When I dip my nozzle in the gel, my machine doesn't want to light up and it soots a little but not much and the welds are fine so I doubt oily felt is causing your problem...you have a gas problem. I put some big dessicant packs I got from a shipment inside the chassis where my wire spool is...seems to help during the humid weather and I threw my felts in the burner. Keep your wire dry and the lid closed and you won't have dirty wire...felt cleaners...IMO..gimmick. Like I said earlier...you're getting some decent gas coverage because your weld isn't porous and all slagged up but IMO you're not getting enough CFH or too much and swirling or you have bad gas.