MIG vs TIG welding on Hawk

[Toxicwst]

Even though I am relatively experienced in all things.... the following does not denote me as a complete newb or unexperienced builder.
Can anyone specify the type of aluminum on the Hawk, and who has MIG vs TIG welded on the frame or swingarm of this beautiful beast?

I ask not because I have a project in mind, but because I am thinking of purchasing a welding machine and I need one to "Do it all" as it were.
Being the proud owner of a Hawk, an R6, and a VW bus, I can think of a few reasons to get a single machine to repair steel and aluminum.

[riot]

Well I cannot comment on what might be best for the hawk, or what process was used to originally weld it (I think MIG),

I plan to buy a TIG setup for my home shop.

Basically, MIG is better for heavy gauge, and where you can get away with less precision (or skill). It is definitely preferable for speed, and the equipment is cheaper.

But for fine work, there is a lot of stuff (especially thin stuff) you can do with TIG that you just can’t with MIG. You can do all of the stuff with TIG, it’s just gonna take longer.

What kind of rigs are you looking at? I plan to get a Miller (Diversion 180) or Lincoln Square Wave once the shop is set up. I’m also debating actually taking some classes. I have some experience with TIG, but at some point if I’m going to do structural stuff (like frames) I’d like to have more confidence in my welds.

[ParcNHawk]

If you want to weld aluminum then you will need an AC welder. Either MIG or TIG it doesn't matter.

When I say AC, I don't mean that it plugs into a 120 or 240V socket... I mean it has to output AC.

Aluminum is NEEDS to have the polarity flip to keep the weld clean.

The advantages of MIG:

• You can do it 1 handed.
• You only are applying heat when you are actually welding

Disadvantages:

• Pushing soft wire is difficult and it tends to birdsnest. A spool gun is preferred.
• Having a steel and aluminum welder involves switching between guns for each metal.
• You are limited to whatever filler actually comes in wire form.

Advantages of TIG:

• Vast choice of filler because you can use sticks... and of any size.
• Allows you to be more precise (when you become skilled) because you are heating and filling separately.

Disadvantages:

• It takes 2 hands and 1 foot.
• Because you heat and fill in 2 distinct actions, you can overheat the aluminum. Aluminum conducts heat really well... so you gotta be very quick and good to make the welds good.

Don't even bother with a MIG rig that is NOT synergic.

[halfast]

If you are going to be doing a lot of aluminum, than I say get a tig. Aluminum is hard with a MIG, in my opinion, and the welds with a TIG will be so much prettier. Just practice, practice, practice on scrap. Nothing more frustrating then laying down a nice row of dimes and then sssplat and blowing a hole. If you are mostly going to be using it with mild steel, I think MIG is easier and quicker, but again practice a lot before tackling aluminum. It's easy to bung up an aluminum job with a TIG, it's far easier to mess it up with a MIG. My amateur opinion.

[Tripleman]

For welding aluminium I would go with a Tig,I use a friends rig but have a 200 amp mig of my own. I don’t have that set up for aluminium. Buy a good quality rig, cheap is crap.

[flyinelvis]

A properly set-up TIG rig will result in superior penetration, but takes immense skill, knowledge and artistry to do the job properly. MIG on the other hand is a simpler ‘point and shoot’ approach that can produce sound welds, but travel speed and heat inputs (along with the proper filler) must be properly controlled or you will just be stacking filler material with little penetration.

Years ago, we designed our own driveshafts that had the end caps welded into place using an ‘electron beam’ (EB) welding technique. The weld required a deep penetrating first pass to join the tube to the end caps, then a second cosmetic pass that produced a nice finished appearance. If you can imagine a metallographic cross-section, the weld would resemble a railroad spike or ‘T’. The first time we ran one of them, it failed in competition (drivers don’t like a driveshaft gone wild at 10,000 RPM beneath their feet) at one of the cap welds. Metallurgical analysis of the part post failure showed the EB operator did not line up properly on the joint (no joining penetration) and the end cap was held into place with just the cosmetic cap weld. 750 horsepower thru the tiny cap weld proved to be more than the part could handle, resulting in a catastrophic failure, a destroyed floorboard and a pissed driver.

So the learning curve (not that you’ll be doing EB welds) for welding is steep, knowing what you’re doing (not just depositing filler or spooling wire) is critical, especially if you are planning on making repairs. There are at least two different aluminum alloys utilized on a Hawk frame, the rectangular spar frame and the cast steerer/lower engine/peg mounts (and possibly others). Welding an aluminum casting (especially one that uses 35 year old casting technology) is not for the faint of heart. The castings were very porous (ask me how I know) with casting voids and gas entrapped porosity. Repairs or brackets welded to these areas require proper pre and post weld heating techniques and an understanding of the chemical composition of the material to be welded. AND, not all aluminum alloys are weldable, so you really need to know your sh*t.

Well I’m also debating actually taking some classes. I have some experience with TIG, but at some point if I’m going to do structural stuff (like frames) I’d like to have more confidence in my welds.

This is sound advice. Just because the weld is pretty to the eye, doesn’t mean it’s structurally sound.

[ParcNHawk]

MIG on the other hand is a simpler ‘point and shoot’ approach that can produce sound welds, but travel speed and heat inputs (along with the proper filler) must be properly controlled or you will just be stacking filler material with little penetration.

Absolutely. That's why I'd only ever invest in (notice how I didn't just say "buy"), a synergic machine. This allows you to set just the wire speed while a computer balances everything else for you.

I miss my old machine. It went missing when I was packing up all my stuff to move.

[Peteroo]

I recently bought this. Its resonably priced, does most everything(not mig) comes with a nice torch and pedal. TIG225X AC/DC TIG Welder With Pulse | PrimeWeld I plan on welding up the frame and other bits here n there. It has the 120 converter but it really doesnt work, had to get 220 into the garage. kept blowing breaker and couldnt get enough amps into the aluminum(1/8th ")

[6]

I spent the last few years learning to weld. Started with mig, moved to tig.

If you have patience and the ability to push through the learning stages, get a tig welder (with a thumb switch option! lots of times you cant stand on that petal in a comfortable welding position. .) and learn to tig.

If your attention span is short and you want to lay down passable welds with minimal effort spent, get a mig.

Want to learn to drive in an auto, or a stick? You will learn to drive the auto easier and faster, but learn to drive in the stick shift car and you have more control over the vehicle and will be able to drive just about anything.

But be honest with yourself, if you don't have the time and energy to learn, buy yourself a mig welder. Its just plain easier.

[ParcNHawk]

Love the first review of that welder:

Screenshot_20221205-193346_Firefox.jpg
I just used it today (long term test)

To weld a cast transmission case seasoned with lubricant... no mention of pre heating or post heating. But it worked "great."

Wrote the review before the case cooled (and stress cracked from the cooling alone).

I guess they never drove 10,000 miles on it today just before writing the review.

Verified buyer... so the person made the purchase. Verified.

I'm not saying it's not a good welder... but the review is 100% pure bullshit.

[bogan]

Depends on the budget, good Migs that do Ali are expensive, previous work used to spend 35k on each Ali Mig and about 25k on the Tigs, which is probably 25k and 15k in freedom dollars.

I find you can get away with a cheaper TIG with pedal and a nominal amount of knowhow, but a cheap mig is a steeper learning curve to get it set right, then it's easy as pie.

Personally, I have one of each (only a DC MIG though) because they're useful for different jobs, mig is just so good to point and shoot and get things done quickly on bigger fab projects, if you're just doing vehicle stuff, definitely the TIG first imo.

Oh, and it's pronounced Aluminium

[Peteroo]

i cut my teeth on my old mans lincoln tig 255. nice piece of equipment even if its older. Il say that the prime weld i picked up performs just as well with the size of projects i would ever attack. its crazy, in DC its silent. you just hear the high frequency start then the gas. AC is a different story, i tend to wear ear buds during that. the high pitched buzz gives me anxiety. if you need to weld ehausts or sheet metal its gotta be tig, you can tack with mig but to finish it up you really need tig for thin stuff. Also, im not sure if i ever saw an ac/dc Mig machine. Is mig nice to knock out something quick? definitely. But an ac/dc tig is more versatile but prepare to practice and get a good grinder. FWIW, im still pretty awful despite taking a tig course but there arent many more rewarding feelings when you put down a good shiny bead. But id be interested to see what kind of aluminum rod and success people have had for welding on frame....

[rpcraft]

I spent the last few years learning to weld. Started with mig, moved to tig.

If you have patience and the ability to push through the learning stages, get a tig welder (with a thumb switch option! lots of times you cant stand on that petal in a comfortable welding position. .) and learn to tig.

If your attention span is short and you want to lay down passable welds with minimal effort spent, get a mig.

Want to learn to drive in an auto, or a stick? You will learn to drive the auto easier and faster, but learn to drive in the stick shift car and you have more control over the vehicle and will be able to drive just about anything.

But be honest with yourself, if you don't have the time and energy to learn, buy yourself a mig welder. Its just plain easier.

I recently got exposed to a pressure sensetive tig button for the torch. I have yet to buy one and test it but seems like a game changer overall. Kind of the best of both worlds. It's a pricey unit though. 275 USD - https://www.6061.com/tigbutton.htm. I can keep using my current switch for now. Maybe one day when I break down and make some chassis stuff for the 64 C10, lol.