Do I need to be talked out of buying this?

[falcon62]

http://www.harborfreight.com/cpi/cta...emnumber=91811


OK so I already know this is a cheapo Harbor Freight tool and the price reflects it. But is this a good deal?

What I want is to be able to weld aluminum. I already own a Lincoln MIG welder that I can buy an aluminum welding kit for. Which would be a better way to go?


BTW, I have zero experience with TIG welding......

[Chris Olson]

If you are wanting to weld TIG on Aluminum you should be looking for a welder with high frequency arc stabilization.. when you weld with that welder you would need to scratch start (touch the tungsten to the work) this can contaminate the tungsten and cause a porous weld

If there are only one or two projects that you might want to fabricate from aluminum you can easily convert a regular MIG welder to run aluminum wire (like .030" 4043)
you would need to change the gun liner to a nylon one and change the gas bottle to straight Argon.

[falcon62]

My dad & I are thinking about building an aluminum trailer. It needs to be big enough to carry his little Kubota tractor. I just want to be able to haul a car when I need to.

Is a 135 amp MIG welder enough to tackle a job like that? Or should I be learning to TIG weld?

Thanks guys for the input!!!!


Travis

[JimmieD]

Chris was absolutely right. As for welding aluminum with your MIG, it all depends on how thick the aluminum is. If you are talking about heavy channel sections for frame members then your 135 cannot handle it. For lightweight sheet panels and fairly small parts you have more than enough power. I'd contact the Mfgr. and get some specs from them on your machine's capabilities.

As for TIG, it is a very complicated process requiring a high level of skills. I would suggest taking courses in a local voc-ed or night school if you want to be any good at it at all. It requires precise hand control [both, simultaneously] a keen eye, and a very steady grip. Machine voltage adjustments are critical also. If you are an accomplished acetylene welder then it's not so very hard to learn, but don't kid yourself into thinking you can learn at home to just get by.

TIG is very expensive even for a startup rig. The cost of consumables is high. It cannot be performed outdoors unless you fabricate close wind screens to keep the gas from being blown away, which can ruin your welds. It requires the highest maintenance costs of equipment.

You could get a Miller MM210 or Hobart equivalent for the same price or less, and be able to weld any aluminum, stainless, cast iron, steel, alloys or anything else you're likely to come across and yet it is a simple MIG machine to operate and lasts for many years. No, it will not produce the beautiful welds on aluminum that a Tig unit can, but that takes a lot of experience anyway, and MIG welds are just as strong!
JimmieD

[JimmieD]

One other sobering thought: if your home-made trailer decides to break in half while hauling the tractor or car then the liability issues are astronomical! The plaintiffs would eat you alive in court, and there goes the whole kit and caboodle. If you've never lost the caboodle take my word for it, it is most unpleasant and sorely missed when gone.

You might drop by your local night school or whatever and have a chat with a welding instructor about this plan, as they could steer you in the right direction.
JimmieD

[falcon62]

Hey thanks guys for your input. I think for now I will buy the aluminum welding kit for my Lincoln Pro-MIG 175. I now wish I had bought a slightly larger welder :( Oh well.

Maybe then I can get some aluminum welding practice in while my dad & I decide how bmyuch of our caboodles we want to risk :)


One other thing. My friend has a TIG welder and all he does is one handed welding. Meaning he doesn't use a filler rod at all. I assume this is the wrong way to use a TIG. Can you get a good weld doing that?

Travis

[JimmieD]

Hey Falcon,

That's a yes and no answer there. Yes, you can get an excellent weld 'one-handed' without filler rod, depending on the joint type and thickness of materials. That method is normally restricted to thin materials and sheet stocks or non-critical components.

Anything structural usually calls for filler rod. A weld is normally v-grooved before it is welded in order to get good penetration on the root [first] pass. If necessary, subsequent fill passes will finish closing the gap.

Miller, Hobart and Lincoln all have welding sites on the net where you can pick up valuable information. Of course the best bet is to take a welding class at night school or whatever as the instructor willl have a lifetime of knowledge to share with you, plus you won't learn bad welding habits from the start.
JimmieD

[HWooldridge]

I bought a used TIG at an auction and taught myself to use it. A buddy of mine bought a used Miller MIG with a spool gun for aluminum. We are both about equal in skills and have been weldors for over twenty years but he learned to weld aluminum much faster with his setup. I like my TIG but if you are an occasional welder, you are better off with the MIG plus it is faster to use.

[tonkadoctor]

MIG welding aluminum

I have many years welding aluminum having worked in machine shops, sign shops, US Navy, shipyards etc...as a welder.

In my experience with MIG welding, I have always hated the Nylon & Teflon Liners. Every one I have used has worn out quickly and the wire pushed thru the sides of them and knoted up inside making it a real pain to repair.

Yes they are the recommended tubes but I would never use another one of them, I personnaly will always use the steel liners. as long as the tube length is less than 10 ft.

One other thing to note is that aluminum wire expands rapidly as it gets hot and I also recommend using one or two sizes larger tip with aluminum wire or it will get stuck at the tip and weld itself to the copper quite often causing you to have to replace the tip if you can't free it up with side cutters. IE .030 wire use a .035 or .040 tip. this also helps with using the steel liners for a reduction in friction so the aluminum wire doesn't wad up before it goes thru the tube.

Of course if you can afford it the cobramatic guns that have rollers in the head to pull the wire and the Miller spool guns (1 lb spool is in the head) is the best way to go with MIG for aluminum.

Proper Gas flow rates and the cleanliness of the metal is critical with welding aluminum. If the pressure is too high it creates turbulance inviting contamination and making it hard to weld as well as risking blowing a big hole. Not enough pressure alows contamination and risks blowing a big hole and dirty metal is both hard to weld to and the contamination will make it easy to blow a big hole.

Unlike steel where you can usually tell when your gonna blow a hole aluminum acts differently and when conditions are right (or wrong depending on your point of veiw) it will drop out in a big blob really quickly.

Use stainless steel wire brushes to clean the seams of aluminum before welding.

I'm not trying to scare you here...just want to stress a few points and highly recommend that you spend time to practice first before tackleing a project. If you like working with metal aluminum work can be very satisfying to work with.

Best of luck to you.

P.S. Buy quality when it comes to tools like this and tools for the shop. Save harbor freight and all the rest of those chinese tools for the 2 lb sledge and emergency tool kit you want to let bounce around in the toolbox on your truck so you don't have to worry about losing an expensive tool in a parking lot at midnight in the rain.

I'll buy something cheap now and then but I'm careful what I get like a $89 gravity feed sandblast cabinet that holds 100# sand, but I have a 6.5 hp craftsman shop vac to go with it. Air tools strictly craftsman professional, Devilbiss & Chicago Pnuematic, sockets wrenches all craftsman, Hammers cheap & heavy, electric drills & saws cheap Craftsmand and Black & decker because I rarely do woodwork just nice to have when you need it. Buy tools according to how you plan to use them, If you get a really good deal on a quality tool and only need it one time you can usually get all of your mony back if you sell it when you are done. I recently bought a quality mini lathe, milling machine & drill press combo on EBay NEW and Unopened for $103 (about 30% of retail price)assembled it and used it for about 3 months and then sold it on EBayfor $380, good tools keep their value.

[falcon62]

Hey thanks for the info. I didn't realize that you needed to use a stainless steel brush. Those are the things that are going to get me.

Does anyone have any good websites where I can learn some more techniques about aluminum welding?

[HWooldridge]

Google on "welding forum". There are several listed - even one expressly devoted to TIG questions.

[tonkadoctor]

stainless brushes work best

a small stainless brush slightly bigger than a toothbrush is all you need inless you have a dremel tool or die grinder.

your buddy welding without filler is somewhat wrong, but this tecnique does have its time and place if your are welding overlapped sheetmetal.

the filler rod is to add metal so you don't undercut the metal while welding.

I enjoy TIG welding and if I could afford one I definatly would get one. you can do some really pretty and detailed work with a TIG torch. I used to be able to weld aluminum foil together with TIG using a foil strip for filler metal and a magnifying lens in my helmet. it used to be pretty funny to watch other guys in the shop get frustrated trying to duplicate this not knowing I was "cheating" with a magnifying lens.