ok... having some trouble making nice welds
well, partially

below is a pic of a recent weld
usually, I can get a nice weld going. good penetration etc.
and then out of the blue, it'll start sputtering and globs of weld start to stack making thick ugly welds

what's my problem?
- hand/eye coordination
- wire speed
- amp setting

any tips/pointers?
please help me out... I hate the look of ugly welds and it's a huge PITA to grind 'm out and start over

You are using a shielding gas set up??
Clean the sufaces better...

Maybe a tad more amps

tot ziens

Could it be impurities on the surface, and not so much your welding technique?
If this happens and you are concerned with the appearance and/or ultimate strength I would recommend having a die grinder handy with a carbide burr to grind out the offending section and reweld. Going over the top just leaves the impurities inside, often in the form of a big gas pocket.

You're using a MIG, right? I know that when I swapped out my lining there was a marked improvement. Big lesson for me. Also related, I've had people wrap my line really tightly which isn't good for the lining either. Maybe new gun pieces are in order as well.

Amperage looks O.K. from pic, clean clean clean. Dirty metal, rusty metal does not weld well at all. (unless stick welding) clean BOTH sides of the metal if at all possible. Depending on the welder, some of the cheaper machines have a coller that simply slides on (as opposed to threading on) and what happens quite often is that as you weld, the collar tends to slip further down the torch head causing the shielding gas to disperse before reaching the weld. Also make certain there is no breeze to blow the gas away, it doesn't take much. 15 C.F.M. is plenty of flow for welding.

Is that weld thru primer or regular paint? If it's paint, get it outta there! Get it ground to good clean steel a couple centimeters from the area to be welded, and your results will be better. Even if it is weld thru primer, it still helps to get it off, when you can.

Aside from that, adding heat or reducing wire speed will lessen that, but of course you can go too far the other way. I like to adjust my welder to the point that if I stop in one spot it'll burn a hole. That way when I'm welding I'm always at the verge of burning through, but I get good penetration. Also, the extra heat seems to help burn off impurities ahead of the weld.

Looks like you're out of gas.


KT

surfaces are clean
no rust or paint (except a thin coat of weld through primer)

Mark, what do you mean with "lining"
the wire?

oh and yes, this is a MIG with gas

You need to clean to a nice shiney substrate before you weld. But you knew this already!! is this a trick question?

was your tub dipped?

Liner runs through the sleeve, and the wire runs throught the liner. Liners must be appropriate size for the chosen wire, or the wire can get kinked inside the liner. Liners can also get a kink in them if they are ever crushed or folded too tightly. Also check the tension on your drive rollers inside the machine. Prolly not the problem but check it anyway. Best way to check is to run your wire into a piece of wood, the roller should be tight enough to feed the wire but loose enough to free spool when the wire hits the board, this is to prevent the wire from "birdnesting' should you ever lose your arc. Yes it happens!

Get some scrap of the same guage.
Turn up the voltage and turn down the wire speed.

Practice with that "new" setting and see if your results improve.


KT

The liner is what keeps the MIG wire from jamming as it goes down the hose. As they get older or bent the wire doesn't feed out as smoothly. It doesn't look like you're out of gas or having gas problems. When I forget to turn my gas on the welds are a big splattery, cratery mess. Those are relatively clean welds.

Dude wazzup

120 volt machine, wire size?...
Try reducing wire feed speed, less gas, hold your tip closer.
I don't trust the regulators and go more by ear. Drag a file on your groung clamp. Both theses things add to a declining quality of weld over a piriod of time.

Later

I see evidence of off-gassing. (the white haze) you are cooking some filth into your weld. after cleaning the metal, give it a light pass with a torch just before welding it up. this will draw the moisture out and if it is chemically contaminated, you will see it discolor or smoke. this woudl be an indication of additional cleaning required

QUOTE (MecGen @ Nov 21 2005, 07:06 PM)

120 volt machine, wire size?...

Ja-roon is in Holland I think... They don't have pansy 120volt electric there - everything is 220/240V.

QUOTE (fiid @ Nov 22 2005, 11:08 AM)

QUOTE (MecGen @ Nov 21 2005, 07:06 PM) 120 volt machine, wire size?... Ja-roon is in Holland I think... They don't have pansy 120volt electric there - everything is 220/240V.

yep, we got 220V standard and 380V as power (comparable to your 110 and 220)

wire is 0.6mm

talked to the guy from the bodyshop today and he's gonna get me a different type of wire that should work better with older metals

thanks for all the input and I'll keep ya posted

All I can add to this is your bad welds look ten times better than my best welds!

It looks like when you get around this issue you are going to have some really nice looking welds. They look a lot better than some of my welds.