Dam, it's about time you posted!

I live in Florida. 4 ton A/C unit, with planet-sized air handler. (My place is ~1500 SF. It's common for larger homes to have two A/C units this size.) We have no municipal gas, so electric furnace, electric water heater, electric stove. The service in newer homes is typically sized to allow for a swimming pool. That's 10-20A for the pump, plus another 40-60A if you're a pussy and have an electric pool heater.

Funny you mention grow-lights though. An old cow-orker of mine back in OH, who was an even bigger geek than me, got a visit from DEA one day at his home. Apparently CG&E is in the practice of ratting out people living in isolated areas whose home electric bills jump suddenly. No plants, but several old mainframe computers.


That's one of the ones I was looking at. Seems like a reasonably sized unit for DIY'er use.

Did you have any previous TIG experience, or this this your first time?



Found some info. From A TIG Buyer's Guide from Miller:

AC TIG is generally used to weld aluminum and magnesium
materials. These metals instantly form oxides when exposed
to air. Before the parts can be welded, the oxide must be
removed. While it can be cleaned manually, the oxide will
quickly form again. Alternating current aids in removing
this oxide layer by cleaning the weld puddle.

Makes sense if you think about the physical movement of electrons in an arc. Tip positive should draw impurities out of the material, but at the expense of concentrating most of the heat production in the electrode. A/C is a compromise that provides scavenging without melting the tip. The fancier models can apparently modulate the relative pos/neg duty cycle too.


And apparently, with TIG setups you can use argon for all your welding, rather than keeping both CO2 and Argon tanks on hand. Long-term cost savings.

If you have the money, I would go for it. Just make sure to keep the flux core for tack welds and really hard to reach places. Trust me, Trying to use TIG in a really tight space takes a lot of experience.

I just started using one when I was working on the FSAE car, just get some scrap and practice. Its sorta like soldering in that you have the feed rod, but other than that its not similar. The infintably adjustable pedal is real nice too, can help prevent blow outs and you keep welding.

Like I said before, TIG heats the metal alot more tho, so just watch for warping. Bit it is a lot of fun, and just using argon is nice.

Looks like that Miller is the replacement for my Syncrowave 180. It's a great machine. IIRC, my 180 was supposed to have a 100 amp breaker, but I had a spare 80 and used it. I have capped it on max amps and never tripped it. The nice thing about a decent sized TIG is that you can stick weld with it as well. Maybe doesn't mean anything for most of you, but on the farm when it comes to implement repair, it's nice to have.

Don't be afraid to search ebay even on an industrial machine. Mine came from PA, but in reality, they all ship from the factory, so take the cheapest one you can find. Mine was $1350 list, got it for right at $1000, free shipping, no sales tax.

I have a Lincoln 175 plus MIG as well. I'm not really biased, either red or blue will do you well.

I have a Lincoln welder which has TIG and stick capability. Im also an avid cyclist and I used the welder to build an Aluminum trailer, took be about 4 hours of constant welding to get absolutely beautiful welds going, perfect beads and excellent penetration. a good machine does make a huge differance. My machine is the Precision Tig 225

Joe if your doing thin aluminum i would stay away from MIG. Unless you have lots of scrap laying around that you can poke through. Also for a tig machine i would check craigslist. Lots of "DIY"ers buy these nice ass machines for retail use em for a job or two and let them sit for a few years. I bought my lincoln 150 weldpack with full bottle of c25 (75 argon 25 c02) for 250$ the welder alone retailed for 600. The guy never even finished one of the 5lb spools.

If your serious about learning how to weld. A vocational school is by far the best place to learn the basics. I say the basics because i graduated with my welding degree (full time) and even with the repetitive welding at work (tig fabrication/aluminum) it took me a good 6 months of daily (approx 3ft of tig welding/day mostly out of position welding ex; overhead, verticle, under a table bending like a contortionist to weld for 10 seconds) welding till i could literaly weld anything. And my welds have been sound ever since

Funny short story i thought i would share. My boss's background is in contracting for major housing developments before he came to the frame shop. He had no experience in TIG whatsoever. The only welding he did was over 25 years ago and that was SMAW (stick). In about 1.5 hours of continuos coaching he could make a bead on 1/8th inch square tubing. We have had guys come in for weld tests that claim they can weld and cant even get the pieces tacked togethor.

You want an AC/DC TIG welder. And all (atleast the ones ive seen) "tig" welders can stick too, they share the same current type which is Constant current. My home welder is a Miller TIG Welder - Dynasty 200 DX AC/DC TIG/Stick and its perfect for anything up to 1/2" aluminum in which you would have to preheat the work piece.


Also if you intend to work on your car with this maching i highly highly reccomend you get the "slider" thumb controll for controll rather than the foot pedal. Reason is ive welded under my car with my hand controll and there would be no way in hell i would be able to do it with a foot pedal. Another reason is its always with the torch; no kicking anything across the floor just so you can weld,especially f you need to go to the other side of the shop. After using the slider, i would never go back to the foot pedal unless the hand controll wasnt available.


Let us know what you end up doing as i am curious.

:2cents:

I've considered this as well. After TIG welding my full dune buggy and my Locost 7 frame, it was always a bitch keeping one foot on the ground. I may have to try one, but I'm sure I'll be spoiled if I do.

I believe it pays for itself in versatility. Unless you break torches like we do at work ( once a week cause idiots drop them from 15 feet in the air or rest the exposed coolant lines on freshly welded material) you will never have to buy a new control again. Time is money ;)

I'm not too worried about damage. It's a toy. A cup ususally lasts me 2-3 years.:giggle: IIRC, it's about $200 for a trigger torch. May have to look again. I debated when I bought it but spluged on a Jackson NextGen helmet instead. Probably overkill for a hobby guy, but it picks up TIG starts better than the cheap ones. Eats batteries, though.

Funny thing is i stopped using my miller optrel helmet for a full-time dark helmet. It has a wider view which helps. Its more comfortable. One thing about my duties is getting in tight places or having the workpiece on your stomach to hold it in place while tacking, does not always allow the sensor to go off. I got flashburn real bad one day because of it and havent used my miller since. With welding helmets its another ego booster such as who has the nicer boat/truck/house, or in our case who spools faster and our hp/tq numbers :giggle:

Actually, that's why I went with the NextGen. Field of view is HUGE and it rarely misfires on me, but I see your point in awkward positions.

The switch I mentioned inserts in the panel just above these wires. That's why I assumed it was a switch for polarity... but yes, w/o it it does not let the spoolgun feed wire. I figured it controlled both. :loser:

Oh well. Maybe I'm no expert, never said I was. I just know welding steel/stainless in general w/ a MIG + gas is simple. Welding aluminum is an annoying pain in the ass.

It doesn't help that the "setting guide" on the inside panel of the MM140 tells you where to set voltage/wire speed for different gauges of material and spools up to .030 and I for some reason insisted on using .035 wire for both stainless and aluminum. I'm effectively guessing my settings. :noob:

Get a TIG, I have a lincoln invertec 205 and love it, it does everything with one gas and all the controls are digital and easy to use, the best set up is to have both a mig and TIG, but I would get the TIG first because it will do everything, and then get a mig later. I just bring home my miller 250 mig when I need one from work. If you can get good on a tig you will be a better mig welder.

One thing I'm noticing is that one of the biggest differences between the "cheap" TIG units ($1,500) and the more expensive units is not their maximum power, but rather their minimum power. For instance, the Miller Diversion 165 has a minimum output of 10 amps. The Dynasty series can get down to 5A, and the Syncrowave series to 3A.

I guess this would be useful if you needed to weld two pieces of aluminum foil together.

Thoughts?

That's right Joe. My Miller Diversion can only go down to 10 a, but like you said it's rare to need to go down below that. I can weld auto sheet metal with what I got, don't see a need to weld razor blades etc to show off.

The big difference in TIG machines is that the new technology is away from the heavy transformer machines and into the inverter based units. The Diversion is inverter based and weighs about 50 pounds, the xfmr machines weigh hundreds.
The inverters have a square wave vs the xfmr's sine wave. Square wave is desirable because it is on or off current, not transitioning.

I had never struck a TIG arc until I got mine last month and now I'm pretty decent at running beads on steel and SS. Aluminum is much, much, harder and I'm practicing that. Its like melting candle wax with a blow torch, happens all at once, hard to not melt thru thin stuff.
JD

Another reason I ask about the smaller current ratings. Does decreasing the current make this process easier to control, or does it only make it take longer?

Decreasing the current (amps) will affect your travel speed and how long it takes you to start welding. With the heat controll (either foot or pedal) you set your maximum amps on the machine and fine tune it with the pedal. The trick is to find that median between too hot and too cold also to get the rythem down on adding metal at the right time. Also near the end of the weld you will back off your amps because the piece will start getting heatsoaked and will wet way to much and burn through.

Joe, I started TIG welding a couple of years ago, bought a DVD on how to TIG, and read up on it. I MIG welded for years, and I'm not going back.

TIG is easy, get a decent used machine (I got mine for $200 used, 120amp DC.) here are my thoughts:
-Start w/ fusion joints (no filler), easy to start w/ and very clean looking, as strong as parent mat'l if prep'ed properly (has to be a butt weld)
-Scratch to start is a PITA, my machine has, will make learning harder but not impossible
-Foot control is nice, but not a must have. I use a torch w/ controls mounted on it, a bit harder to use than a foot pedal though.
-You'll need a tank of pure Argon, I'd rent one (get a big tank)
-TIG makes the best looking welds IMHO
-You can TIG a tin can together w/ TIG (I've seen a guy weld FOIL), nice for thin sections (body work), a pulsing unit is nice.
-You don't need classes, it's very easy once you get the feel for it
-Adding filler is going to be a difficult step, most welding I've done doesn't need filler, just fusion welding.
-Stay away from the chinese ones, a Millermatic is nice but overkill; wait for a good basic used one.
-You need to set current for the mat'l thickness (pretty much), don't want to use to low a current or you'll end up w/ a huge heat affected zone

I would just get a unit, we'll help get you welding.

Also, get an electronic auto darkening helmet; TIG welding flash is serious, ebay is fine, all made in china. I paid $50 for mine, no complaints.

Here's one:
http://cgi.ebay.com/Miller-Maxstar-1...3A1%7C294%3A50

Can't do aluminum, that feature is going to cost you