MIG welding and advice

Technical Manufacturing
1

Today the robotics team walked into our machine shop to clean it, and found this:

It is a MIG welding torch.

Now, we do not know who left it there (we have our suspicions) but, if they are interested in letting us keep it, we would be VERY happy to use it. Myself and one other person on the team do have experience using a MIG welding torch, plus we could see if a sponsor would be willing to send us one of their professional welders for further instruction.

This would be the first time we had a welding torch, and the question arises if this room would be alright for welding. http://4.bp.blogspot.com/-_pNE_KK5cM8/UeXrJ0lF5rI/AAAAAAAAALo/CyVVcVi4_og/s320/IMAG0184.JPG

We could get access to a table that we need for it, and we would probably either open a window, or, if needed, install a vent for the excess gases.

Next, in order to weld aluminum, the manual says we need 100% Argon gas. Where can we get this, and how expensive is it?

Thank you for the help. More pictures can be found on the blog here: http://robolions3397.blogspot.com/

2

I’d suggest getting some sort of booth setup with some kind of curtain as a door. The arc from an arc welder (such as MIG and TIG) is as bright as the sun, and can cause eye damage easily. If you cannot get a booth, make sure there is some sort of see-through welding curtain. That way you can safely see what is going on inside without being blinded. The arc can also cause sunburns to people nearby it. We have a heavy leather coat that our welders wear when they tig weld for that reason. (we don’t MIG weld our aluminum)

(you can see the curtain we use in the pictures I attached, and you can sort of see the booths we have in the background. Sorry for the poor image quality, I had my friend record a video of me TIG welding with my phone, not the best image quality)

As for gas, yes. It does have to be 100% Argon. That can be bought at different welding supply stores. I’m not sure how gas refills go for us because we haven’t needed to refill it during my time on our team, but the closest place I know is an Airgas store.

Praxair seems to be a really credible place to buy it too.

http://www.praxairdirect.com/Specialty-Gas-Information-Center/Pure-Gas-Specifications/Argon.html

I’m not sure on the price. I found on a website it is $.50 per 100 grams.

Hope this helps!

7-16-2013 9-46-01 PM.jpg
7-16-2013 9-46-01 PM.jpg1264×846 81.3 KB

7-16-2013 9-46-28 PM.jpg
7-16-2013 9-46-28 PM.jpg1264×846 88 KB



7-16-2013 9-46-01 PM.jpg
7-16-2013 9-46-01 PM.jpg1264×846 81.3 KB

7-16-2013 9-46-28 PM.jpg
7-16-2013 9-46-28 PM.jpg1264×846 88 KB

3

If welding steel is like stitches, welding aluminum is like brain surgery. It is challenging, and you absolutely must have competent instruction.

You cannot weld indoors without full and complete vetilation. “open a window” will not cut it. The room also needs to be essentially fireproof - sheetrock is not fireproof.

If you ever weld steel with that welder, it is useless for aluminum. If you dedicate it to 100% aluminum, and use the right supplies, then MIG welding (really, GMAW*) will work well for aluminum.

100% argon is not much different in cost from any welding gas. You will find that it is not a great expense, even if you rent the tank (common) and the regulator (usually you buy one), the cost of the gas is comparable to a nice dinner for four.

So, your next steps:

  1. Can you really keep it?
  2. Get someone who is an expert aluminum welder (not a steel guy who has done some aluminum. Trust me here) and have them help you…
    3…find a good aluminum welding wire, and…
  3. A source of gas, and…
    5…Invest in a set of “aluminum only” tools (your welder will explain)
  4. And personal protective equipment (mask, gloves, apron, etc)
  5. Then find a location approved by the fire marshal (in most states you require a fire dept. permit to do indoor welding)
  6. and practice, practice, practice. Then go and practice more. After 100+ feet of welding bead, you’ll be passable.

This is NOT a lot of money, but step 2 for advice and instruction is critical…

Don

*Gas Metal Arc Welding
**Disclaimer: I know a lot about aluminum welding, maybe too much, but my eye-hand coordination stinks.

4

In order to weld Aluminum with a MIG you have to have a TIG gun. As far as getting gas I would contact a welding gas supplier near you and lease the tanks, OzarkGas is who I would contact first. They are extremely reasonable and highly qualified.

5

  1. I think we can keep it, mostly due to the fact that the only keys to the room that was in are in possession of our captains, our coach, and our teacher sponsor (who expressed interest in giving us a MIG welder).

  2. We can do this. The guy who welded our aluminum robot last season ( http://www.chiefdelphi.com/forums/showthread.phpt=114320&highlight=Serenity) was a professor at the local Tech College, and is very good at his job. He can teach us.

  3. What is an example of good aluminum welding wire?

  4. We should be able to find some thanks to Justin

  5. I will ask him tomorrow

  6. We can get those

  7. We might have an area in our school’s wood shop (away from all of the wood) that would allow us to have ventilation and a curtain, and be fire-safe, we would check with this to be certain (to make sure it is no going to mix with the wood).

  8. Sounds like a plan.

Thank you so much!

6

OzarkGas will be able to get you anything you need for welding; gas, wire, guns, etc… And hope you have a great experience with your welder!!

7

I have done Aluminum TIG welding, I taught myself, (I think I did one steel TIG weld), I can TIG weld aluminum better than steel, which isn’t saying too much.

  1. clean the surfaces very good
  2. use stainless steel wire brush( and only use it for this purpose)
  3. electrode distance from material should be 1/2 the electrode thickness
  4. when the weld puddle turns reflective, start inserting filler rod (you can melt through very quickly wspesially with thinner metals, so this takes skill)
  5. practice, practice practice :smiley:

not 100% shure on #3, been a while.

8

Always consult the manuals, and defer to experts. I am neither, just someone with a fair bit of FRC experience and a bit of welding practice under his belt.

First off, congratulations! Welding is a great resource to have, and although MIG welding is more difficult with aluminuim, don’t let that stop you. Compared to TIG welding, MIG is faster to setup, so you can run more beads, but is more difficult to get right. Finding the right wire feeds and power levels are very important to getting good results. Think of it this way: although our main student welder and I love TIG welding aluminuim, he welded two full 1/16" alu frames last year with good results. MIG is still a great way to go.

I wouldn’t recommend welding in there, at least not just with a window open. Others have more experience with this, but we weld in a dedicated booth with one of those welding safety curtains. The walls are plaster, I believe, but the floor is some type of concrete or sheetrock. We weld on an (unfortunately not flat) metal table. Keep in mind, technically, exposing even concrete to high temperatures can have disastrous consequences. (Such as when doing aluminuim casting, the molten aluminuim can vaporize moisture in the concrete with, shall we say, dangerous results. Welding shouldn’t get the concrete close to those temperatures, though, even if you weld right on it.) So, be safe. We also use a fume hood. In your case, I’d consider welding outside. If you use appropriate safety equipment, don’t weld tired, and have proper training, welding isn’t dangerous, and it’s quite fun. Don’t be scared away. That said, consult experts and manuals first.

One last thing, this probably isn’t the first time you’ve heard this, but welding is hard. Like really hard. Welding practice is not only a lot more fun than CAD practice, but essential to getting good results. You’re going to need at least several days in the welding booth before getting even passable results. Also, warping is a real issue. Weld on a surface you KNOW to be flat, and check everything’s squareness after tacking and every weld, squaring everything again if appropriate. Weld carefully, and be smart. Oh yeah, and in case I haven’t said this enough already, listen to those with the most experience (the experts).

Good luck, have fun and be safe!

9

Sorry to derail the thread a bit, but why would welding steel make a welder no longer fit to weld aluminum? The obvious answer is that it messes it up in some way (just as crimpers that have been used as pliers will never crimp again), but how?

10

It’s because you have to have a completely different setup to weld aluminum then you do steel. I wouldn’t say it makes it completely useless but it’s expensive to keep both setups and time consuming to switch back and forth.

11

In a former life time, I TIG welded steel & aluminum with the same equipment. Aluminum generally needs a bigger welder, a HF starter & is pickier with the shield gas.

MIG is slightly different. Since aluminum is softer, you generally need a spool gun rather than having the wire feed in the welder so the wire does not kink.

As previously stated. Have an expert help set up the machine, advise you what you need. & teach you how to weld. The thinner the pieces you are welding the more difficult it becomes.

12

Well, maybe it was a slight overstatement. In reality, if you buy a new gun and hose (and drive wheel for some welders), you can swap them for steel and aluminum.

The issue is one of contamination: A tiny bit of steel dust (even at the molecular level) will cause your aluminum welds to fail or be very weak. For this reason, you must take extreme care that no steel of any kind - dust, grinding debris, or even the residue from a welding gun used for steel - gets on or near the aluminum. That’s also why you need a stainless steel brush and must dedicate all your aluminum welding tools to aluminum only.

In the automotive world, where aluminum repairs are common, it is almost universally mandatory that a body shop have a dedicated aluminum roof in their shop. Just being in a corner “away from the steel” is very insufficient. At the very least, a curtained-off area that you wash down with water before using anything is required (for car repairs, which are safety-sensitive).

Again: A good aluminum welder will tell you all this, along with helping you find good wire and other supplies.

Welding IS fun, but it really is hard, too. Worth It.

13

New just arrived:

  1. The MIG welder is ours

  2. We happen to have an old welding booth at the school! We will just need to replace the old Steel table with a new aluminum one, get the gas (which our teacher sponsor is going to try to get the school to provide) and some equipment, and we are good to go.

  3. Our local welder is happy to come in and teach a few of us to weld aluminum.

  4. The nearest OzarkGas supplier is 30 minutes away, we are gonna see if we can find someone closer, preferably local.

Thanks for all the help, it looks like 3397 will have ourselves some welding next year.

14

All I can say is good luck.
My expectation you will be very disappointed after spending the $ to swap it over to aluminum welding just to find out that the machine/welds are not able to reliably meet your needs. If you want a consistently good weld with a low machine cost tig welding has the advantage over mig welding. (The cost of Mig welding with this welder is not worth the investment. You need a spool gun that pulls the wire out not pushes the wire out. If you use this welder with soft AL wire, it will make a birds nest in the unit. The best way to mig weld with Al you will need a new lead with a pull drive in the head of the gun. It is NOT worth upgrading this welder! Yes they have the adapter to be able to weld AL with this welder but please do your research before you put any thing into this welder.) If you are welding anything 1/8" or under you will be more pleased with a tig welder because you will be able to control your temp, looks better and it will produce the clean and strong weld without porosity! For example look at this welder,
http://www.millerwelds.com/products/tig/product.php?model=M00337
Best of luck.

15

Be sure that you understand welding processes before you give out too much information. MIG and TIG are abbreviations for the same process (GMAW), but differ greatly in the fact that the machine, electrode, filler material delivery, cost, much more are dissimilar.

You can MIG weld aluminum, but as mentioned the contamination is hard to avoid if used for other materials. Also the quality of weld achieved from a MIG welder is generally not to the same level as one can get with a pedal operated TIG set-up. It should still be plenty fine for FRC uses, but don’t expect beautiful flowing material spec rated aluminum welds out of the machine that the OP has.

For gas, check some medical supply shops and a quick google search for your area based on city alone brought up a handful of welding supply shops. Looks like you guys are in the Airgas supply area, as well as many others. Between Airgas, Delta, and Rod’s you have your choice of 3-4 shops within ten minutes of the city listed in your location.

The best advice is to get some training from someone who knows what they are doing and then run through a whole spool of wire practicing. But, practice on the same material you will be using during the season. If you are buying a particular type of aluminum tubing, get a chunk of it. Buy a lot of usable drops from your supplier and start burning holes in those until you can get a reliable bead built up. Then start connecting pieces together and see what it takes to break them apart. Some of the most fun we had in welding classes was the “toss test.” Just find some concrete and chuck a test weld in the air ten or fifteen feet. If it survives the landing then move on to the real part to be welded.

And have fun, welding is one of those addicting hobbies you never seem to stop doing once you start.

16

If that MIG unit is less than 200A (it says 125 on the front) you’ll likely run into some issues with aluminum.
As mentioned you want 100% argon as well.

My Hobart 210MVP has a spool gun but there’s limits of what you pull off with low power delivery.

17

You will probably only be able to weld up to 1/8 maybe 3/16 inch aluminum plate with that machine. We have a 180 amp Miller TIG welder on campus which can weld a little under 1/4 inch Al. When we have our robots welded, some of our thicker components (1/4 - 1/2 inch) have to be taken to our welders off campus shop with a more powerful machine.

18

In practice MIG & TIG are very different. In MIG your electrode becomes the filler & is consumed. In TIG your tungsten electrode is not consumed & should never touch the weld puddle. While you can buy machines that do both the setups are very different.

19

Exactly right, but both MIG and TIG fall in the category of Gas Metal Arc Welding (GMAW) by using a shielding gas (Argon, Carbon Dioxide, etc.) rather than Shielded Metal Arc Welding (SMAW) using a flux coated filler material. What you said is exactly what I wanted the poster to look up and learn on his own.

20

Not to be confused with a flux core wire welder which looks a lot like a MIG. :wink: