First time welder ??? Then get a stick welder... Mig's are only good on new clean metal and you would need to spend around $2000.00 for a good one to weld 1/2" or thicker steel...
For around $200.00 you can get a stick welder that welds almost anything but aluminum ... You can also use a stick welder to cut metal...

I've tried several of the 110 volt welders with little success. The Lincoln SP135 does a decent job but as kbeitz mentions it doesn't have enough heat to burn into "dirty" metal. Also the flux core wire is nothing more than a self feeding stick electrode. However the mig is easier to weld with than an arc welder, but you really need a 220 volt unit to do you much good. If you are dead set on a little mig, make sure it comes with a gas valve and a liner in the cable to carry the gas, you WILL be wanting to upgrade to gas down the line.

A Lincoln or Miller/Hobart AC 200-230A 240V stick welder is a good choice as a basic machine. Nonferrous and sheetmetal are about the only things you can't do with one.

If you get an AC/DC model, you can retrofit it with a TIG kit for almost anything.

I concur with kevin(get the stick machine), I feel everyone should learn oxy/accetylene first, then stick, then mig, etc....
But then again it may be because thats what I did and it seeemed to work for me.
When you say you want to build trelises, do you mean a few for your own use or set up production for marketing?
You may want to seriously look at machine capabilities including duty cycles, nothing worse than outgrowing a machine faster than you thouhgt, simply because you didn't know enough about the capability or your need.
DED

I have a MIG PAK10 welder made by Lincoln several years ago that has served me well. As others have posted, it's good for beginners but won't weld the thicker stuff. Since most of what I do is Hobby welding/fabrication and mostly on small stuff, it is fine for me. 6yrs and no problems.

Chad

I like the HH 175 I have, but as others have mentioned, it is limited somewhat on the thickness of the pieces for a single pass. It is awesome with C25 gas 1/4 inch and smaller. Otherwise, multiple passes are required to get a sound weld (for me, YMMV depending on skill level, I'm no pro :).

For what you want to do, a 120 volt mig/flux core would work, but remember, welding is addictive and if you need to weld thicker matial, you might wish you got a larger 220V machine. The plus side of the 120 V unit is that it is more portable.

I used an older 220V 170 amp Harbor Freight mig welder, and it worked OK. The Hobart is better however. The wire feed mechanism and the gun were the biggest differences I saw. Also, I think getting parts for it would have been a problem on the HF model.

I also used a cheap 110 volt arc welder (70 amps believe it or not). I could get it to work, but burning up 1/16 rods all the time with multiple passes got pretty old. Mine makes a good paper weight.

Kurt

The harbor Freight 120 Volt won't work with much more than 10 guage metal (Has worked well for me on mower decks) I have to agree a 220 Volt stick welder will be better for what you looking for.

I use a Miller Thunderbolt 225. It is a 220v AC machine. I also have a 110v mig for light metal. Here is a picture of my rose arbor. It si designed to come apart into 3 sections top and 2 sides.
{{!gwi}}
Top section close up
{{!gwi}}
Middle section This is where it comes apart. Look closely at the square section 4" below the curved part.
{{!gwi}}

This is one of my welded arbors...
{{!gwi}}

We bought a little Lincoln "crackerbox" welder- at least that's what people call it around here. It's wonderful and has built most of our barn house. I cut the steel, and Mr H. welds it. It seems to be a good general use welder for common metal projects.
Mrs H

Here is a link that might be useful: the barn house project

Wow that barn looks like alot of work...

Yes, it has been lots of work, and we hope to be finished around Christmas, but will still be putting a cuppola on top around next Spring. This project started about a year ago. We work on it on our days off of our regular jobs.
Mrs H

My vote is the Lincoln MIG PAC 10 (for 110volt) or the MIG PAC 15 (220 volt) either with gas

Great for small stuff
Yes you need to clean (Grind) your metal (WE ALL SHOULD)
If you need to weld larger stuff that requires abit of strength all you need to do is fit it properly. Grind a "v" joint and fill it properly, multiple stringers not one big blob pass

THEN THERES ALL YOUR SPECIFIC NEEDS WELDS ??????
Thanks
Roscoe

Interesting comments on the small, cheaper welders. I am also in the market for a 115VAC input welder, but so far it appears there aint one with enough amperage output for the "stinger". As steel gets thicker, you need more amps to make enough heat through the arc, or it aint going to weld with enough penetration, or so my welding class instructor has been hinting. I got about a year to go before I can certify, assuming I continue to progress well with the skill tests. He is a bit picky about appearance and such things on the skill tests of the welding examples we turn in for grading. At this point I know what he will take and what he will not.
At the Tech Center (old name is Voc Ed) we started out with oxyfuel, which was mostly acetylene torch welding, and then did some oxyfuel cutting torch. After the required beads, butt joints, T joints, and lap joints demonstrated and accepted for grading, we moved on to Shield Metal Arc Welding (SMAW) with E6011 and E7018 rod. That is where most of us are after starting in mid August. If you want to learn how to weld properly, with safety training and such, the local state Tech Center is the cheapest way to go. I have already learned enough so far to extend my life a dozen years compared to what might have happened if I had of read books and did self-help OJT.
I am on stick welding at the moment, but am learning I am alergic to the fumes of SMAW. I wear a 3M respirator under the helmet that helps a lot with the coughing and whezing at night, but the younger folk still in high school just tuff it out. Not smart, but hey, they are young. Later we do TIG and MIG and aluminum, then steel pipe, like 6"-8" pipe. I have little doubt I will feel "educated" in the fall of next year since there is a big summer break. Hard to say enough about "professional" education the State Tech Centers provide.

there aint one with enough amperage output for the "stinger".

That was my experience with the 110V stick machine. I use it once in a while for fun, but it gets old quick :).

Just stop in at your local welding supply and look at the 220 volt lincoln mig welder a 135 or 150 will weld anything you want most likely, be sure to go ahead and get the setup for shielding gas as the flux core wire is just junk, you will need a tank of gas (75/25 for mild steel) and a flow gauge also be sure to pickup some extra tip and other consumables might want a can of nozzle dip or spray to it works real well, they can fill you in on all the details at the welding supply . No need to suffer thru the oxy acy welding and stick welding unless you plan on welding for a living. Just about anyone can pickup Mig welding in a couple of hours. My six year old recently welded some plates together for show and tell at school. He even signed his name on the piece with the welder, he said it was just like writing with a pencil. Good welding machines are not cheap and cheap welding machines are not good.

Kbeitz,

Cool car! Looks like a '38 to me, but I can't quite figure out the make. Love the little trailer, too!

Santa brought me a 110V wire welder from Harbor Freight for Christmas. I have read this post a couple of times since it was originally posted, and while I think you guys a correct if the person is going to build substantial projects, but a little 110V wire welder used to stick together yard art as the original post stated will be an acceptable cheap tool. I have access to industrial welders at work both arc and wire, an I was rather suprised when I first tried my new toy. It was easy to use and like the guy above I plan on getting my grandson involved since its so easy to learn. As a side note; I work with a boiler maker and he was intrested in my new toy, and when done testing it he said the next time he had to crawl under a car to weld an exhaust pipe he wanted to use my welder. Bill

I have never welded before but got a friend that can teach me I was jw what is a good welder to start out with? If u can let me know by email badmugzz@gmail.com thank you

I have the 110v flux core from harbor freight and I love it. It works well with mild steel up to about 3/16". Anything after that and you won't get good penetration for a strong structural weld. It will do 1/2" rebar though and if you have a small gas torch you can pre-heat your metal to get a little more penetration. Flux core also has one serios advantage over mig/gas in that you can use it outdoors even on a breezy day without worrying about the wind dispersing your shielding gas. Nothing worse than a weld full of air bubbles