1. Get the best ground clamp you can find. Some mig welders come with Chincy ground clamps.
Buy a good one like the one in the picture above.
Millers newest ground clamp with copper contact points on the jaws and a shunt. Getting a better ground will give better starts, which will give you a better weld.
You can make a special ground attachment out of an old section of welding lead. Just some bare woven copper wire wrapped around the part like an anaconda, will give you so many tiny ground points that you will never lose your ground.
2. If you're a noob, one of your best resources for mig welding settings is this page on ...
MillerWelds.com and don't forget to visit other welding forums, and watch all the videos you possibly can.
One of the best things you can possibly do....and by the way , hardly anyone does this, is to pay someone to show you how to get started.
Have you ever tried to learn a new software program all by yourself and when you are ready to cuss and spit, someone comes along and sits down and shows you in 5 minutes what you just wasted 4 hours trying to learn?
Nod your head yes. You know I am right.
3. You can MIG weld mild steel, stainless, and aluminum. But that doesn't mean mig does equally well on all. Mig Welding Steel is Cake...Stainless is a bit harder...Aluminum can be very unforgiving.
3. Mig welding works much better on steel than for stainless or aluminum. Tig welding usually rules the roost for stainless and aluminum (unless you are willing to invest in a high end mig welding machine and gun).
But if you are determined to do it without a spool gun, it can be done . But You usually need a Teflon liner and weaker tensioner spring at the very least for mig welding aluminum.
And please , please do not try to weld aluminum with the 75/25 argon/co2 gas you use for welding steel.
You will curse you mig machine if you do.
4. MIG is the ticket for general fabrication of anything from motorcycle frames to race car frames to landscaping trailers. But don't try doing any of the above with a little 115volt mig machine. The 115 volt mig machines are great for little projects and sheet metal like auto body repairs. But you need more balls for anything critical like a race car frame.
5. MIG welding does not like dirt, rust, oil, and grease. Here is where the 3 C's come in. Clean , clean, clean.
What is clean enough?
I am not saying you have to grind every weld area to shiny bright metal. That would be great in a perfect world. Mill scale is usually not a problem if good technique and settings are used ... But for rust, oil, and grease, they have got to go.
6. Stay away from anti spatter sprays from you local welding supply. Why would you buy anti spatter spray that has a 5 page msds saying it is known to cause cancer when you can buy PAM cooking spray from the grocery store?
I dare you to try it. Now if you are doing Nuclear Code work this might no be an option because of code stipulations, but for welding in the shop, it is da shizz. Dont you just love to find something that works and is cheap and simple and easy to get?
7. Buy a spare liner and change the liner before it starts to clog and restrict the wire from feeding. If you don't have a spare liner, you will always be tempted to get by with the old one.
8. If you are in the market for a 115 volt mig machine, get one with a gas conversion kit. If you do, You will thank me later.
9. A good general-use wire diameter for the hobbyist is 0.035". But that only holds true for 220 volt machines like a Millermatic 251.
For 0.023" is usually best for the small 115 volt mig machines. Thats what they are made for. Short torches, small guns.etc...
10. Make sure your machine is set to direct current electrode positive (DCEP)-also called reverse polarity for bare wire mig, But don't forget, flux core wires often use DCEN. A lot of 115volt mig welding machines have been sold on craigslist because the owner didn't know to change polarity and thought his mig welding machine was a POC. ( that means piece of crap )
11. Remember to use the right amperage circuit and fuse where you plug in your machine. Make sure your wiring is sufficient to carry the current and please do not try to run a 115 volt mig welder off of a 15 amp breaker and a 25 foot extension cord you bought from the Dollar store.
12. A 75/25 shielding gas (75 percent Argon / 25 percent carbon dioxide) is the standard for short circuit mig welding steel. For high amperage, high production mig welding, sometimes different mixes like 95/5, 90/10 , or even 98/2 ar/o2 are used but don't let that confuse you. For the home and shop, stick with 75/25 ar/co2 for steel and don't look back.
13. A good ball park flow rate for your shielding gas is 20 cubic feet per hour (CFH). But since all flowmeters are not created equal, you may need more or less.
14. Be careful to take the right precautions when you weld in confined areas...mig welding does not work with a fan blowing on you but you still need ventilation. for example, don't stick your head down into a 55 gallon drum and mig weld with inert gases. It can kill you.
15. remember the 3 p's practice, practice, practice.. but is it good to practice doing something wrong over and over? See tip #2
16. Although most manuals recommend wire stickout (from nozzle to steel) of 1/2-in. to 3/4-in., I recommend using as little stickout as possible. Except where you want to soften the arc like when weldng thin sheet metal.
When welding thin gauge, allow more wire stickout-even up to 3/4-in.
17. Don't get all hung up on whether to push or pull the weld. When in doubt , try 90 degrees dead nuts and go from there and do what you have to do to get the job done.
18. Relax your hand. Without even realizing it, noobs grip the torch like it was the head of a rattlesnake. Relax, and watch the puddle.
19. When you need to control distortion, Backstep weld on thin sheet metal-or step weld....weld a couple of inches at the beginning,middle, end, and then come back-If you weld a long seam all at once, you are likely to warp the steel.
20. Do a few down and dirty destructive tests to make sure your machine settings and welding technique are giving you the results you need. A simple t joint done on the same thickness and then broken with a bfh. (big freaking hammer) will go a long way in verifying weld settings.
21. It's a common saying that your machine should sound like bacon frying when it is set right on short circuit. Actually if should be smoother than that with less crackles and pops.
But for Aluminum mig welding, the bacon frying is not what you want to hear. You will want to hear it humm. Same for high amperage spray transfer welding.
22. You cant teach seat time...the more you burn, the more you'll learn. Don't be a hack... Do it right the first time. Cutting corners usually results in problems that have to be corrected. Good enough hardly ever is. Get er done.
23. Check around when buying equipment. Be patient, Prices vary a lot. Craigslist is a great place to shop for used welding equipment.
24. Wearing a respirator does not make you a wussy. Welding in Short sleeves, ( I have done it way too much) is not a good idea. Keep a long sleeve shirt in the shop.