MIG welding and advice

[Scott L.]

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

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

[DampRobot]

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!

[dictionaria13]

Originally Posted by DonRotolo

If you ever weld steel with that welder, it is useless for aluminum.

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?

[Justin Shelley]

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.

[FrankJ]

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.

[DonRotolo]

Originally Posted by dictionaria13

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?

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.

[Walter Deitzler]

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.

[Mrnye]

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/...p?model=M00337
Best of luck.

[techhelpbb]

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.

[ttakashima]

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.