We frequently see "What should I buy" questions; one example is "What MIG welder should I buy?" There is no definite answer, and the prospective buyer should read the other entries in this FAQ regarding welding. What follows is an example of such a question and the answers received (June, 1993). We claim no responsibility for correctness or liability for your money!
Keith King asked:
I'm looking at the purchase of a MIG welder for auto body repair and other light welding jobs around the homestead and I don't have much background on this type of equipment.
The models I'm looking at are the Lincoln SP-100 and the Miller 130. Both models are 110v portables. The Miller has a higher rating but I'm not sure if that's critical for my applications. The Lincoln has the advantage of having infinitely variable power output vs. stepped output for the Miller and the salesman said the gun on the Lincoln was a "Tweako?" whatever that means. Both units are similarly priced/warranted etc.
Century has a bunch of lower priced, shorter warranty, cheaper looking, MIG welders.
Does anyone have any experience/opinions on these welders or other MIGs to help me make a more informed purchase.
Jim Narem answered/asked:
I'm also interested in MIG welders for sheet metal and roll bar work. I've used the Italian made SIP 110V MIG unit. It works; it was worth $100 (purchased at some close-out sale) but not the $350 that places want retail. It's tough to get parts; even the tips have to be ordered. The wire feed mechanism sucks.
I've seen some new Lincoln's on the market; both are wire feed welders with optional MIG kits as opposed to the SP-100 and SP-130 which are purpose build MIG units.
Lincoln Weld-Pak 100, 88 amp, 18V @ 20% duty, 110V, $354 w/MIG kit. Lincoln Weld-Pak 125, 130 amp, 20v @ 30% duty, 220V, $556 w/MIG kit. (Prices are Connecticut Home Depot, tax bandit not included)
The MIG kits are about $80 each, they have a gas flow regulator, solenoid and (I think) a different gun.
Does anyone have any experience with these welders? They seem cost effective compared to the SP-100 and SP-130 but I'm nervous since Lincoln seems to be releasing some home/consumer grade equipment (like their new AC arc welder with the cheezy variable amperage control).
There are also several Century MIG units commonly available at large home improvement shops (yup, WELD on that new addition). I've used their AC/DC arc welder and was impressed with its cost/performance. Has anyone used any of the Century MIGs?
Ken Clarke answered:
I took an evening welding class at a technical high school (10 weeks) and got to try various types of welding (stick, MIG, TIG, and oxy/acetylene. Also got some good tips on safety, and on how to by a MIG welder.
The instructor spoke of the "big three" in the welding business (Miller, Lincoln, and Hobart). He was a confirmed "Miller" man, but we used Lincoln (and Airco) welders in the tech. school. I now think that it makes sense to buy whatever you decide to buy at your favorite welding supply store. The guys there have lots of good advice and if you go with one of the big three, you will not have any problem getting parts and consumables for your welder.
I looked around for a while and compared the 110v portable welders by Lincoln and Miller and Hobart. My favorite welding supply house was having a "package deal" that included the Hobart Handler 120. Included in the package was the welder, a 2 lb. spool of .024 wire, a Jackson welders mask with the 4x5 face plate (get a number 10 shade), a *good* pair of welders gloves, a 55 cu. ft. tank of shielding gas (C25 which is 25 percent CO2 and 75 percent Argon), a dual-gauge regulator and connecting hose. This was about 1.5 years ago and I believe I paid $625 for the package.
The Hobart has been great. It works fine on auto body panels and I have also done work on exhaust systems, mailbox posts, minibike mufflers, lawnmower parts, and am finishing up a trailer axle for a friend this weekend.
So, I guess I'm advocating the Hobart, but if you can get a good deal on the Miller or the Lincoln, those would probably be fine, too.
A few of the features on the Hobart that I liked were:
1. A "purge" feature, that allows you to set the flow rate on the shielding gas without spooling out wire.
2. The wire feed mechanism that lets you set the tension on the drive wheel but also lets you change wire spools without moving the setting.
3. The ergonomics of the unit, the way the wire spool goes in, the way the lid hinges down (not up like the others).
4. Five year warranty on power diodes and SCRs, three years on major components and one year on parts and labor.
I would stay away from the Century welder. I don't think it has the quality of the "big three". I think you would have trouble getting parts, probably would have to order them. All parts for the big three can be had at local welding supply houses, in-stock. Also, the "Tweeko" comment is referring to the gun end of the welder. I hear that it's supposed to be a very common industry-standard type of part. Parts for the Tweeko handle/gun should be available at any welding supply house.
Jim Swonger answered:
"Tweako" is actually Tweco, a manufacturer of MIG and TIG handpieces and such. What this means is that parts are pretty readily available; they're everywhere.
For sheet metal welding you'll run nowhere near the maximum heat setting on any machine. On my 160 I'm down on "2" for heat. The higher current machines of some of the cheaper brands need to be looked at carefully; some of them have -very- low duty cycles, leading me to believe that the critical parts are not much, if any, better than the cheaper models.
The "purge" feature is good to have; however if you do not find a machine with it you can add it pretty simply. An auxiliary control switch for the solenoid valve is all it takes, in parallel with the relay that runs off the gun trigger.
For serious sheet metal work spot and stitch modes are very nice amenities, allowing you to tack up a large piece with spaced short beads, minimizing distortion and allowing a fast, even hand motion. You can get by without it, but if it comes free or cheap...
Quite a while later (26-Sep-1993), mrehmus@ix.netcom.com wrote --
I've owned a Century 90 amp MIG welder for 4 or 5 years now. Never a problem with the unit and I've put three large reels of 0.024" wire through it. The one time I thought I had a problem the people at Century were very helpful. Century may not be one of the "big three" but they have been around for a very long time (mainly they make many of the professional battery chargers sold in this country, so I'm told).
Other comments that have come up from various sources, especially Ken Clarke:
Arc welders are often rated for a particular duty cycle, such as 30%. This means you can weld for about 3 minutes at full power, then you have to let the welder cool off for 7 minutes. The cheap units are typically low duty cycle, where the professional units have a high duty cycle. Also, units are often rated at a certain lower amperage where they can safely be operated at a higher percentage; for example, a 200 amp unit might be rated at 50 amps @ 100%, 100 amps at @ 60%, and 200 amps at 30%. Look for some sort of automatic cutoff to protect your investment in case you get carried away.
DC systems are nicer than AC systems, especially if you can reverse polarity. AC systems splatter a bit more. DC doesn't as much, and makes a nicer weld as a result. Reversing polarity apparently can direct heat away from, or to, the workpiece; directing it away from a sheet metal weld can reduce warpage.
Inverter models run off DC, or rectified line current. Their portability is the main selling point, for field welding where 220V isn't available. For the home or small shop, they are probably overkill.
Large spools of wire, or other welding supplies, may corrode before they get used up in a hobby environment. Dry storage is important to preserve them.
In late 1995 (10/1), Ernie Leimkuhler (ernieleim@aol.com) wrote:
The best of all the baby migs are the Lincoln SP-125, Miller 130, and Hobart Handler 120. All 3 are gas MIGs that can also run flux-core (but why would you want to if you don't have to ?). I own a Handler 120 and have loved it for the last 3 years. I've welded stainless, aluminum and steel with it without a hitch, although the aluminum capability of all the baby migs is pretty limited. For regular steel I use a 75% argon / 25% CO2 mix, but if I need to do a bunch of stainless I swap my 75/25 bottle in for a bottle of Helium-tri-mix. This gives hotter, cleaner welds on stainless and as long as you own your tank it doesn't cost much to swap out for a specific job and then swap back. Eventually I suppose I'll buy another tank, but for now it doesn't seem worth it.
Flux-core is only recomended where a sheilding gas is likely to get blown away, such as in-the-field repairs. It is considerably nastier and means a lot of cleanup.
BTW instead of buying 10 lb. ($50 - $60) spools of stainless, I buy the little 1.1 lb ($6 - $7 )spools made for spooler guns. This saves a bit of money for small jobs, but if you are doing a lot of stainless, it is cheaper per pound to buy the 10 lb spools.
Remeber to match you filler metal on stainless, other wise you can get some funky welds. 308L SS filler wire is used for 304 SS. 316L SS filler wire is used for 316 SS. (The "L" stands for elevated temperature stable).
The Hobart, Lincoln , and Miller machines all run close to $500 for a package.
I would stay away from the cheesier brands on principle allthough some members of this newsgroup have bought them and been quite satisfied. The problem is that the low end companies tend to have probems with warranty repairs and replacment parts, whereas the larger companies have certified repair stations all over the country.
All these machines have similar max output amps and tend to max out on 1/4 inch plate steel. For thick sections just preheat to above 400 deg F.
-- to which Jim Campbell ( campbellj@fdtc.flo.TEC.SC.US) replied: The Chicago Electric systems also have a clever marketing scheme that uses non-standard wire diameters that may commit you to using their systems and materials only. That's probably why their machines are priced rock-bottom, especially through Harbour Freight. [See next comment by Altavoz. JK]
For those asking Mig theory questions, are you getting enough info in your operator's manual (When all else fails)? A good little book on Mig is ESAB's "Mig Welding Handbook" revised in 1994. Only $7.50 and evaluation copies FREE for students/educators/advisors to schools, or whatever. ESAB was once Union Carbide/Linde. They may sell a small Mig unit too, but I am not familiar with theirs. ESAB's snail mail is: PO Box 100545 Florence, SC 29501-0545 and voice is (803) 669-4411. (I do not work for them, but use their mechanized stuff).
-- Altavoz (altavo19@IDT.NET) points out that Chicago Electric is actually Harbor Freight's name for an Italian company. He's had no problem using their .035" tips on Tweco handpieces, contrary to Jim's previous comment.