MIG welders

[rayjay]

Re: MIG welders

You have to keep your gas nozzle cleaned out. It gets filled with spatter and then won't give you a good arc. One thing that will really improve the 110v welders is to replace the power cord with a high quality stranded copper, large gauge line. I had a Snap On 110v welder { Century } and it seemed like it had 1.5x the amps after upgrading the power cord.

 

[Dunaruna]

Re: MIG welders

Originally posted by deputydawg:<br /> It will often sputter a lot. Instead of the nice arc it will sound like poppoppoppoppoppop and deposit small balls of weld on the surface. Not enough penetration to hold anything. But then it will kick off and run great for a few inches. <br />

That the classic symptom of reversed polarity or you may just have a bad earth clamp connection and as it heats up it connects better. I don't know about your specific mig but every mig I ever seen is reversible, sometimes its a switch and sometimes it requires delicate surgery (like mine!). Ya gunna need a manual. Not enough gas or the wrong type of gas will also cause grief.<br /><br />Nozzle dip grease is great for keeping the tip & nozzle free of splatter balls and cruddy buildup, also try using a tip that is one size bigger than the wire. I'm using 0.8 wire and 0.9 tip (metric), haven't had to replace the tip or cleanout the nozzle after 3 x 5kg rolls. <br /><br />Aldo

 

[Stratosfied]

Re: MIG welders

Been a long time since I mig'ed but it seems that if there was some oil or grease residue on the material, it just would not weld and go crazy. Just a thought.

 

[Nos4r2]

Re: MIG welders

just a tip- if you're going to weld anything with galvanising then clean it all off well around the area you're going to weld- Zinc poisoning will give you a particularly unpleasant 24-hour illness.Argoshield gas in a confined space is also poisonous. Always weld with adequate but not excessive ventilation-wind will ruin a weld as it blows the shielding gas away-even on gasless plants.<br /> Make sure any joints are spotlessly clean before you weld them with no oil,grease or oxidation- I usually cut to +0.5mm with the oxy cutter and grind back to make sure. <br />If you're doing anything structural then be particularly anal about this-grease or oxides can cause hardspots or slag inclusions in welds, which is where cracks and fractures start.<br />I could go on about this for hours- I spent 3 years learning the finer points of welding and the metallurgy associated with it but for basic stuff that's pretty much all you'll need to know.<br /><br />Be aware that your 100 amp mig welder won't be able to weld anything over 3mm thick though-it doesn't have the power to penetrate the workpiece properly. Also remember that Arc-eye is painful (it feels like your eyes are FULL of sand) and cumulative.While you may not have a problem with tacking up without a mask to start,eventually it'll happen almost immediately. You won't realise until it's too late either.<br /><br />and yet another...<br />MAKE SURE YOU'RE WEARING LONG SLEEVES WHILE WELDING! I did one of my certification testpieces in a t-shirt (being naive) which was about half an hour of welding time. This was in a British winter and I'd lost all the skin from my arms within a week. Never underestimate how much UV an arc produces.<br /><br />waffle over!

 

[deputydawg]

Re: MIG welders

Thanks for all the help. My cheap mig I have now is finally working better. I think I failed to clean the metal good enough! <br />I have been arc welding for many years. back in the mid 80's I took classes on welding. In high school FFA I entered welding and mechanics contests and got 1st at the state level in welding. But only arc welding. I worked as a welder for a while after high school. very short term job. Welding hard surface protective coating on farm machinery. I had a big ball of slag roll into myu un-tied tennis shoe one day so know of those burns. I have been awakened at midnight with a screaming pain from burned eyes. Until now have only MIG welded once, with an industrial size welder the school had. Now all I weld is car bodies, frames, roll cages, that sort of hobbies.

 

[Barlow]

Re: MIG welders

got a question here guys.. I was taught to hold 1/4 - 3/8" away from the surface working in the weld in circles .. is correct, no? <br /><br />and pushing and pulling the weld varies on the application??<br /><br />I've got to break mine out perty soon again and I'm a damn idiot cryin' fool when it comes to this. I welded a whole crap load of junk when I first got the thing but its been a few years .. experience prior was repairs w/stick welder on farm equipment so the grinder came out when the welder did.. yea, pathetic! <br /><br />thnx guys ...and pardon the question dd .. just wanted to make it quick.

 

[deputydawg]

Re: MIG welders

If I remember right you hold the MIG a little closer than the arc welder. You need to hold a smaller area for the gas to stay in.<br />You can weld in small circles, crescents back and forth on the line your welding, or for a strong ugly weld make figure 8's with the weld.<br />With all welds you hold the end at different angles for different welds and steel. Right angles stick the rod more into the corner. Thin metel hold at an angle aiming the rod or welding gun ahead of your weld. This will give a good weld with less penetration. Hold straight up and down will give less penetration but a wider weld. The most common is to drag the rod aiming it at your trail. This holds the heat there longer and gives a deeper weld. <br />If I remember right hold the rod about 1/8 inch from the weld. Should get a smooth sizzeling sound.

 

[Nos4r2]

Re: MIG welders

You hold the mig TIP further away than the arc welder- the arc welding shielding gas comes from the flux burning away therefore you have a lot less of it-but saying that you should have an arc length of no more than 3mm max when arc welding. You can tell a good arc weld when the slag lifts off as the weld cools without using a chipping hammer. <br /><br />With mig I use approx 5-6mm from the tip to the workpiece.<br /><br />I find crescents are the best method when welding flat-Arc or mig-but keep them small (2-3mmm)-if you make them any bigger you risk overheating the workpiece and causing more heat distortion.Better to do a "root" run then a capping run than to put a whole lot of weld down at the same time-this way also improves the properties of the root weld metal.<br /><br />There are various methods for welding overhead and vertical- most involve using a "xmas tree" shaped weave to keep the weld run under control-but again, keep it small.4mm-5mm max works well for me doing 6mmm plate.Thinner plate means smaller movement.<br /><br />While welding if there's a good line of sight to the weld itself watch for the workpiece metal burning SLIGHTLY away and being replaced with weld metal. This is generally a good rule of thumb for good penetration-though on material less than 3mm thick you shouldn't be able to see this-it'll just burn through.<br /><br />No insult intended here deputydawg, but I was always taught that an ugly weld is defective- all welds should be uniform size and texture. Any pitting/unevenness is the point where a crack will start. You can always grind out the weld at the point of the pit and re-weld that point. It's not as good as doing it in one run but it's stronger than having a pit there.

 

[Tinkerer]

Re: MIG welders

Whatever you do don't buy a SIP Migmate 130.<br /><br />Nasty little machine with a lousy and unpredictable wire feed that feeds OK for a while and then decides to do nothing. No adjustment can sort it out. No manufacturer support here, despite major stores selling lots of them, and nobody can solve the problem. So I'm stuck with a $500 machine that is pretty much useless and not heavy enough to be a good mooring.<br /><br />I bought mine about three years ago after carefully researching it in magazine reviews, which were all positive. Either the reviewers are idiots or the machine I got was a lemon. Either way nobody should buy one.

 

[Paul Moir]

Re: MIG welders

Hey, Tinkerer - is this your machine?<br /><br /> Migmate<br /><br />I don't know how much you tinker with electronics, but he did some relitively simple things to his to fix the speed control.<br /> Fix.<br /><br />(...and I thought the one on my Lincon was kind of crummy!)

 

[Dunaruna]

Re: MIG welders

Originally posted by Nos4r2:<br /> .Better to do a "root" run then a capping run than to put a whole lot of weld down at the same time-this way also improves the properties of the root weld metal.<br />

110% agree, thats the secret to a strong, goodlooking weld. Most hobby welders won't give enough penetration - their just not strong enough. Over stitching (sometimes 3 or 4 times) keeps the machine cool and overcomes the duty cycle problems.<br /><br />Heres my take on angles and methods of welding, every job is different - different materials, different welding angles etc. Get some scrap and practice. Crecent, figure 8, pull & push, distance from material and angle of torch. Also play around with the gas pressure but don't exceed the max on the gauge (the red area). <br /><br />Aldo

 

[Tinkerer]

Re: MIG welders

Originally posted by Paul Moir:<br /> Hey, Tinkerer - is this your machine?<br /><br /> Migmate<br /><br />I don't know how much you tinker with electronics, but he did some relitively simple things to his to fix the speed control.<br /> Fix.<br /><br />(...and I thought the one on my Lincon was kind of crummy!)

Paul<br /><br />Thanks.<br /><br />It's the big brother to my one. Same set up. Same problems too.<br /><br />At least it confirms that the speed control is part of the problem rather than being solely my lousy welding. <br /><br />The electronics fix is beyond me. What I know about electricity is that it comes out of the wall and makes the beer in the fridge go cold. I do some basic electrical stuff if I know what I'm doing but I don't tinker with 240V electricity. There's already enough ways to die.

 

[Barlow]

Re: MIG welders

deputydawg, Nos4r2, Aldo - thanx for the instruction an help guys.<br /><br /> I've got a wire feed nowdays - stick while growin' up around the farms. <br /><br />I appreciate it!

 

[deputydawg]

Re: MIG welders

Nos4r.... you are very right about a good looking weld being stronger. I meant the stule of the figure 8 weld is ugly. If you look at the weld it should have uniform loops on each edge of the weld, and the middle will be a smooth even ridge. Similar to the christmas tree you described. <br />When I was in tech school at Central community college they instructed on both the figure 8 and the tree you described. The finish weld was almost identical. <br />I only wish when I was in school learning welding, I would have continued beyond basic arc welding. I was studying atuomotive technology and needed a filler credit so I took a semester of welding. We used arc mostly, gas brazing, some TIG and some carbon arc. I think we spent about an hour on the MIG. I do wish I had stuck with it.<br />Thanks for the information, you definately know your stuff. And everyone else here, thanks for all the tips!

 

[Nos4r2]

Re: MIG welders

Agreed deputydawg... Arc is by far the hardest to do properly though-If you can arc weld then MIG will be a breeze. The hardest part is learning to set up the plant you're using properly. I prefer TIG or oxy-acetylene though, it looks beautiful and you've got more control.<br /><br />Enjoy!