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View Full Version : What not to do with a MIG welder



Black Forest
04-17-2013, 02:08 PM
Today I made a really dumb mistake. I was tacking a small piece to a big piece and using my hand to hold the small piece in place. I was only wearing a pair of light TIG gloves. No helmet. So I position the small piece put the MIG gun in place, turn my head and pull the trigger. The wire went through the gap, through my glove and into my index finger. It really hurt when the wire hit the bone in my finger! The good thing is the molten tip cauterized the wound on the way out. Nothing serious I hope. Just a swollen finger and it hurts big time.

So the moral of the story is don't get lazy. Use the correct equipment.

Did I mention my finger hurts a lot?

KIMFAB
04-17-2013, 02:14 PM
So you got your training at Orange county choppers?

RussZHC
04-17-2013, 02:15 PM
Just this past week..."tick" off the front of the face shield, had no clue what it was (pretty cold outside so just thought is was plastic creaking), looked where I had been working and one nut of 4 nut and bolt assembled was MIA...had been wire brushing flux and must have just touched the nut, spun it off real quick. Very, very happy I try to play safe.

vpt
04-17-2013, 02:21 PM
That sucks! Very good thing to keep in mind though, keep your hands away from the weld area. Thanks for the lesson!

BigMike782
04-17-2013, 02:33 PM
Before I had an auto darkening lense I had some sheetmetal to tack in place.Position,turn head,tack......did that a hundred times or so.The next day the sid of my face burned like sun sun burn I have ever had.I went and bought my AD soon after.

John Stevenson
04-17-2013, 03:12 PM
Clumsy bastard...........

achtanelion
04-17-2013, 05:07 PM
I did that years ago in shop class. Put the wire into the ball of my thumb. You have my sympathies.

J

Boostinjdm
04-17-2013, 06:24 PM
Watch carefully for infection. I've done that hot poker trick to my knee before.

Plain ol Bill
04-17-2013, 06:30 PM
Ouch - been there done that - I had snipped the ball off the end of the MIG wire once and it drove the wire through the finger and then arced on the far side turning the wire red hot. That will make you wet your pants!

Stern
04-17-2013, 07:19 PM
OWCH, glad to say I have never had the pleasure of jamming a MIG wire through a body part (probably because I consider the MIG a big useless boat anchor, have 2 and never use them). If I cant ARC it, I TIG it. As for the turn head and tack, I never could understand why people do that (first saw this on OCC, and figured "well they are idiots anyway". Even when you dont need to "watch the melt pool" I still like to see what Im doing when even tack welding. Im pretty cheap when it comes to my hobby, but I did spend $300 + on a good AD helmet (more than all my 6 welder cost together, mostly because most were free lol). Have done welding without gloves (and payed the price with nasty burns a day later) but have NEVER welded anything without a helmet on

vpt
04-17-2013, 07:38 PM
I have a tig/stick and bought a MIG for the dirty jobs. I also do the turn your head and tack for some quick deals (most 4 tacks).

_Paul_
04-17-2013, 07:41 PM
I feel your pain, watch out for infection pop a drop or two of Tea Tree oil on it just in case.

Not to hijack but my worst was the big ball of red hot steel from inside the torch shroud dropped between the big toe & it's neighbour took a chunk of flesh off that never came back, more fool me for welding in dappers (pumps).

Paul

Black_Moons
04-17-2013, 07:50 PM
My fav "Worst part of mig welding" story is from my brother...

"Well, I usally wear ear plugs at work. But at home, Yaknow. So here I am doing some overheld welding at home when some splatter manages to make its way into my ear.. And I can hear the earwax boiling away... And that, Is the worst part of welding"

John Stevenson
04-17-2013, 07:52 PM
OWCH, glad to say I have never had the pleasure of jamming a MIG wire through a body part (probably because I consider the MIG a big useless boat anchor, have 2 and never use them). If I cant ARC it,

Horses for courses.
I'd be dead in the water without a Mig welder, a 15kg reel of 1mm wire lasts me about 4 - 5 weeks.

http://www.stevenson-engineers.co.uk/files/largerotor3.jpg

That rotor is to take a 65mm bearing and 55mm output shaft and is about 8" long of welding.
Arc is too messy with slag and changing rods, Tig is just toooo slow. Need to get this all welded in 30 minutes max to turn the job round in just under two hours allowing for natural cooling, machining and new keyway.

radkins
04-17-2013, 07:55 PM
I have seen advice on adjusting roller tension for a MIG (even seen this in print!) that goes something like this, hold the tip of the wire against the palm of your hand (with a leather glove) with the trigger pulled then tighten the rollers until the wire is forced out hard enough to bend. Doing this is nothing short of stupid! We had a guy at work a few years ago who did this with .035 that went right through the leather glove, into the palm of his hand, hit a bone in the back of his hand an curled the end of the wire! We had to clip the wire and send him to the ER where a surgeon had to be called in to cut this piece of wire out of his hand. When sniped the end of the wire can be slanted and very sharp but believe it or not a burned end can be even sharper, usually a small ball will form but not always. Sometimes when the arc is stopped the ball will drop off and leave the end of the wire with a tapered point that is sharper than a needle, this point will go right through a leather glove with no effort at all with predictable and extremely painful results.

strider
04-17-2013, 08:41 PM
I have been fortunate enough to not have punctured myself with MIG wire. Seemed good common sense to use a bit of caution and pay attention to procedures and proper equipment. I do need to add one bit of additional safety advice: never - never - ever weld while wearing Crocs.:p

Dr Stan
04-17-2013, 09:09 PM
Horses for courses.
I'd be dead in the water without a Mig welder, a 15kg reel of 1mm wire lasts me about 4 - 5 weeks.

That rotor is to take a 65mm bearing and 55mm output shaft and is about 8" long of welding.
Arc is too messy with slag and changing rods, Tig is just toooo slow. Need to get this all welded in 30 minutes max to turn the job round in just under two hours allowing for natural cooling, machining and new keyway.

When I was in the Navy we used spray welding to build up shafts. If I remember correctly the brands were Eutectic and Utahloy with one considered a "hot" process and the other a "cold" process. The "hot" one used a variety of nickle alloys ranging from similar to stainless steel to tough as nails and a virtual substitute for Stellite that we used for facing 1200 PSI steam valves and similar applications. The "cold" process used a bronze alloy that had to be applied on a "threaded" surface which was cut to make a 90 degree included "thread". They were both excellent for building up worn pump & motor shafts. The torch looked similar to a cutting torch with a plastic bottle of powered metal attached which allowed the metal to be drawn into the gas mixture.

Sure beat running multiple beads and produced a more uniform build up. It also reduced the amount of warping due to heat concentrations.

What I find interesting is that I've never encountered it since I was discharged in 1977 even though I've seen several instances in industry that would have been perfect for the technology.

Here's the location of a good pic of the torch: https://www.google.com/search?q=spray+welding+pics&hl=en&client=firefox-a&hs=ZSz&rls=org.mozilla:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ei=_kdvUePyGrHJ4APKvoGgAg&ved=0CDAQsAQ&biw=1280&bih=846#imgrc=CtLnrb3z7lK_3M%3A%3BsQ0juG_5dgSKSM%3 Bhttp%253A%252F%252Fi00.i.aliimg.com%252Fwsphoto%2 52Fv0%252F315140932%252Fmetal-powder-spray-welding-torch.jpg%3Bhttp%253A%252F%252Fwww.aliexpress.com% 252Fitem-img%252Fmetal-powder-spray-welding-torch%252F315140932.html%3B720%3B504

michigan doug
04-17-2013, 09:54 PM
My condolences.

There is a place in South Bend that does spray welding on crankshafts. I needed one fattened up for an old Lister. The wait was more than 3 months and the price was about the same as a new Indian crank.

doug

flylo
04-17-2013, 11:27 PM
John, I have 2 small systems like that & 1 huge wire system & 1 powder system. 12+ guns spares, a skid of a dozen different wire, 50+ 5# or bigger all different powders, lathe mounts,dual flame sprayers, 2 powders feeders/shakers, 2 power wire feeders, 100+#s tungsten/carbide for oil deill bit hardfacing, At least 6+ Donald loads. In the right hands it's a money maker. For conversation only as I bit off more than my body can handle.:(

wierdscience
04-18-2013, 01:33 AM
Doing something using your hands for a block of wood is about like the old carpenter's goof of using their fingers to feel if the skilsaw is cutting all the way through a board.If it's not fine,but what if it is????:rolleyes:

BF,hope it heals quick.Cauterized or not,when was your last Tetnus booster?

LKeithR
04-18-2013, 03:05 AM
Horses for courses. I'd be dead in the water without a Mig welder, a 15kg reel of 1mm wire lasts me about 4 - 5 weeks.

Yup. Nothing wrong with stick welding; nothing wrong with tig welding--each has its place. But anyone who claims that mig welding is a waste of time is not serious about welding. In this day and age there are many jobs out there that simply could not be done cost effectively without a mig welder...

John Stevenson
04-18-2013, 04:51 AM
First of all let me say that I have never done any spray welding but seen it and the results of it.
I know there are many different types of filler powder and possibly the wrong ones have been used at times but from experience of having to redo sprayed shafts a lot of people are making a lot of mistakes.

What I have found is that I have had rotors in that have been spray welded and the bearing is loose on the rotor but will not pull of because it hammered the powdered surface under the bearing and pushed it in front so it's larger in diameter and won't allow the bearing to come off.

Distortion isn't a worry because all shafts where heat is involved will distort, depending on design, long keyways etc and the ratio of diameter to length affects it. You don't need to worry because you just have to deal with it ;)

Not clear in the picture is the fact that there are two different diameters, larger on the left for the bearing at 65mm and the output shaft at 55 mm finished sizes. That rotor came in with the bearing diameter worn so quickest way is make a sleeve, turn the bearing diameter undersize, whack the sleeve on, tight fit plus loctite and machine back to size - easy job.

So made the sleeve, put the rotor in the lathe to turn undersize and the bastard was bent slightly, get the end running true and bearing diameter and inboard end of the shaft was running out. No way to straighten this at that diameter and short length so turn both diameters undersize wand gob some weld on.

Problem I havenow is I know the centre hole is going to be out, no way it can't be, that's why i say don't worry, just no point.
Can't use the seal track it's sitting on as that is worn slightly oval, not enough to worry about it's only a grease seal plate and nowadays they use sealed bearings anyway. Only good diameter is on the shaft just inside the fins.

This is where you never have enough steadys !

http://www.stevenson-engineers.co.uk/files/largerotor4.jpg

THIS is a steady !!
4 Jaw chuck with integral bearings on a MY4 shank. Allows you to dial in and get one surface suitable for a steady so you can single point the centre.

http://www.stevenson-engineers.co.uk/files/largerotor5.jpg

Roughing down to size to make sure everything will clean up. Just to hep support given the steady rollers are not very big I have pushes a scrap bearing up against the end of the shaft.

http://www.stevenson-engineers.co.uk/files/largerotor6.jpg

Centre single pointed and it's clear just how far with the bend and welding it is off.

Just requires final turning and a keyway, no pics of that as I misplaced the camera for a couple of days. Anyway start to finish just over two hours

GKman
04-18-2013, 05:48 AM
Back to the original post, before his majesty hijacked it. Tattoo studios (parlors) here in the states have added exotic piercing to their menu of services. Looks like your mig is the tool for the job. Hang a new sign and be ready for the Goth chicks to beat your door down.

Black Forest
04-18-2013, 06:48 AM
This morning my finger is swollen to about twice its normal size. It doesn't hurt so much anymore.

I finish breakfast and I am heading out the door. Good wife asks me as I leave if I have to do anymore of that welding that I hurt my finger with yesterday.

I answer yes, why?

She smiles and said, "Use your penis!"

Referring to swollen twice it's size I assume.

You just have to love a girl with a sense of humor.

Stern
04-18-2013, 09:20 AM
Yup. Nothing wrong with stick welding; nothing wrong with tig welding--each has its place. But anyone who claims that mig welding is a waste of time is not serious about welding. In this day and age there are many jobs out there that simply could not be done cost effectively without a mig welder...

I do agree with that, but I myself dont use mine (because both are cheap HF units) and cant afford a REAL one (like a Lincoln or similar). With both the HF ones I have the wire feed mechanism is crap, works 10 seconds then jams, hose jams, etc. My buddy had a BIG Miller one that works great, which he uses for aluminum.... but its WAY out of my price range. All my welders are "cheap or free" ones, and all work well except the MIG's (have a 140A and a big 220V one, both crap).
Maybe one day I will get a good one, that is RELIABLE, as having to stop every 2 min to spend 30 min trying to fix something is NOT cost effective lol. I want a nice big Miller one, it even looks good LOL.

LKeithR
04-18-2013, 12:11 PM
This is where you never have enough steadys !

http://www.stevenson-engineers.co.uk/files/largerotor4.jpg

THIS is a steady !!
4 Jaw chuck with integral bearings on a MY4 shank. Allows you to dial in and get one surface suitable for a steady so you can single point the centre.

What a great idea! I've seen 3-jaw chucks on MT arbors but never a 4-jaw. We do the occasional shaft repair and that would be really handy for initial setups. Did you buy it? Or build it yourself?

LKeithR
04-18-2013, 12:15 PM
...You just have to love a girl with a sense of humor.

I think there's more than humour involved here my friend...http://www.shopfloortalk.com/forums/images/smilies/devil.gif

Lucky b*astard!!

brian Rupnow
04-18-2013, 03:22 PM
BlackForest---Here's a story to maky you wince!!! I worked with a lady in Peterborough, and her boyfriend was a welder, with quite a few years in the profession. One day his mig wire stuck. Generally, if it doesn't stick bad at the tip of the gun, a sharp rap on the welding table will free it up and you can continue welding. He gave it a rap---still stuck. He gave it another rap and pulled the trigger---still stuck. He turned the gun up to look at the end of the nozzle and inadvertantly pulled the trigger---and it WASN'T stuck. The wire peirced the cornea of his eye and passed thru the eyeball and damaged the retina at the back of his eyeball. He had a few surgeries, and many months of treatment, but ultimately went blind in that eye. Consider yourself lucky that it was only a finger!!!! ---Brian

Dr Stan
04-18-2013, 03:32 PM
What I have found is that I have had rotors in that have been spray welded and the bearing is loose on the rotor but will not pull of because it hammered the powdered surface under the bearing and pushed it in front so it's larger in diameter and won't allow the bearing to come off.

That's strange. A powder metal buildup should be just as solid as any other weld, especially one of the "hot" processes as one must have a puddle to achieve any sort of penetration just like any other welding process.

BadDog
04-18-2013, 04:51 PM
On the OT line, is there some confusion between "spray transfer" (which is a high energy GMAW process) and metal spray coating process? The high energy metal spray coating is used like a paint gun with internal plasma arc and is a very specialized process often used to add special coatings and buildups. Generally spray is applied in a hot room with water back-catch and separator for "over spray" (coating materials can cost more than gold per oz). Spray transfer is a much more mundane process using a sufficiently powerful common MIG/GMAW power supply. The main obvious difference is the fine grain bead patterns that result.

John Stevenson
04-18-2013, 07:13 PM
Wish my camera had a date stamp on it !

Posted the above post this morning and went into the shop. Guy turns up for a largish chemical plant nearby with two stainless shafts out of mixers.

In the past both had run a bearing and been away somewhere for repair by metal spraying, see why i said need a date stamp - unbelievable.

However both had failed again in the same area.

http://www.stevenson-engineers.co.uk/files/sprayshaft2.jpg

Top one has been grooved for better grip [ which didn't happen ] bottom one hasn't.
Guy was not very impressed as so far they have had these shafts done 3 times each, probably accounts for the grooving / non grooving ?

I offered to repair them with stainless welding but he wanted no part of it and insisted on new shafts because of the down time of changing these. one immediate [ plant down ] and one to follow next week.

http://www.stevenson-engineers.co.uk/files/spratshaft3.jpg

This is exactly the same as I'm seeing on rotors and these come from different companies in different areas. So either it doesn't work or they all use the same dick head at the same company, which I doubt.

Keith, chuck was home built, board the back out and fitted a bearing and also fitted one in the back plate, then made a MT4 shaft to fit them.

BF, Sorry for the hi-jack.

vpt
04-18-2013, 08:34 PM
Sony has a date stamp.

http://img412.imageshack.us/img412/4619/propshaft011.jpg

John Stevenson
04-18-2013, 08:44 PM
Mine isn't a Sony,

metalmagpie
04-18-2013, 08:47 PM
Not to hijack but my worst was the big ball of red hot steel from inside the torch shroud dropped between the big toe & it's neighbour took a chunk of flesh off that never came back, more fool me for welding in dappers (pumps).

Back in my early 20s I was working in a large machinery room on a ship with dozens of tradesmen also working. I swept an area of deck and bent over with a whisk broom and dustpan to collect the debris. Unbeknownst to me a guy above was cutting down a vertical section and just as I bent over a large blob of molten slag dropped - right down my shamefully exposed butt crack! OMG did that hurt! I got 3 little 3rd degree burns. The worst part was for the next six months I had to start my work day by going to the dispensary and dropping trou in front of an old crone of a nurse and bending over an exam table while she dressed it, invariably snickering at my embarrassment. I remember upping the priority on buying a belt after that happened!

metalmagpie

danlb
04-18-2013, 09:07 PM
Wish my camera had a date stamp on it !



It does have one, buried in the EXIF data portion of the picture. I deleted most of the data.

EXIF IFD0

Camera Make {0x010F} = Panasonic
Camera Model {0x0110} = DMC-LS75
Software / Firmware Version {0x0131} = Ver.1.0
Last Modified Date/Time {0x0132} = 2013:04:18 22:53:56



Dan

mickeyf
04-18-2013, 10:49 PM
Somewhere in their Welding Tips, Miller says "hold the mig gun with both hands". I thought, yeah, steadier, but this may be an even better reason. Like when you clip the power cord off some old equipement, always make sure you are holding both prongs of the plug.

Black Forest
04-19-2013, 12:16 AM
Sir John, No worries on the hi-jack. The discussion on spray welding is much more interesting to me than my stupidity with a mig gun.

John Stevenson
04-19-2013, 03:48 AM
It does have one, buried in the EXIF data portion of the picture. I deleted most of the data.

EXIF IFD0

Camera Make {0x010F} = Panasonic
Camera Model {0x0110} = DMC-LS75
Software / Firmware Version {0x0131} = Ver.1.0
Last Modified Date/Time {0x0132} = 2013:04:18 22:53:56



Dan

I knew the information was tagged inside the pic but had forgotten about it.
Looked at the time of nearly 11pm and though that was because I'd edited it to upload but then realised that I had shot back to get my camera and took a close up thinking the first picture was a wide shot but it wasn't.

This is the first pic.


http://www.stevenson-engineers.co.uk/files/sprayshaft1.jpg


Timed at 10:20 and the finished shaft was timed at 3:30pm so by the time I'd nipped out to get some stainless, been on the phone for an hour ;) and a bit of dinner probably took 3 hours, about right.

JCHannum
04-19-2013, 08:47 AM
Many years ago, I worked closely with a motor repair shop that did many repairs similar to Sir John's. Their experience with the Eutectic system was spotty and depended on the skill of the user. They found the best method was a dedicated scrapped lathe to turn the shaft while spraying. They still had the occasional failures resembling SJ's photos and eventually abandoned the procedure.

Related to the OP, I have it on good authority that it is not a good idea to hold a TIG torch close to your ear to adjust the gas flow when the high freq is turned on.

BigMike782
04-19-2013, 09:45 AM
It's not a good idea to lay the TIG torch over your leg with your foot still on the foot control.....DAMHIK.

radkins
04-19-2013, 10:47 AM
It's an even worse idea to lay a TIG torch in lap with your foot still on the foot control!

BigMike782
04-19-2013, 12:06 PM
Hi freq is bad enough but when it jingles the tomatos that's a bad day!