Welding 101

[skb12172]

I would like to learn a bit about welding, but I currently know virtually NOTHING. From looking at the offerings at the local community college, it is a bit overwhelming. The "Certificate" would require over a year of full-time study and the Associate's Degree looks like it would take close to 3 years. I'm also uncertain as to how many of these classes I would actually need, since I don't want to be a professional welder. I'm just looking into this to improve my personal skill set of Useful Things I Can Do.

So...let's start with the basics. What is the difference between Stick, Mig, and Tig? What classes/certifications would I actually need to be a competent, backyard welder? Again, I'm not looking to be qualified to work on the Alaskan Pipeline or in a shipyard, I just want a healthy understanding and skill level.

[Darrell]

I took classes in stick and oxy/acetylene welding to learn the basics. I think a fair bit of oxy/ace carries over to TIG, the motions are similar, at least, and learning to control the puddle; I'm self taught in TIG, and pretty good at it, or used to be. MIG is generally considered the easiest. Practice, practice, practice is key.

[HTRN]

Mig and tig are both gas shielded electric welding systems. The difference is with Mig, the electrode is also the filler material, and is generally wirefed, either from a spool in the machine, or from a socalled spoolgun(typically used on aluminum, as aluminum wire doesn't like being fed through the liner in lead).

Tig instead uses a tungsten electrode, with the welder hand feeding in filler material(if your familiar with Oxy/Acyl, it's a very similar, so much so, that those who generally have least problems picking it up are experienced Oxy/acyl welders).

"Stick" welding doesn't use a shielding gas, instead, is uses a solid flux coating on the filler material(like MIG, the filler is the electrode), which generally comes as foot long pieces that look alot like sparklers.

Please note, that these aren't the "official" names of the processes, but are instead common industry terms.

[Highspeed]

I've read Welding for Dummies and apart from the irritating format of those books ( YMMV ) and the constant nagging about safety it contains a lot of useful information.

I think you should start with a decent MiG ( not gasless like the crappy live torch thing I currently have ) and an automatic helmet ( not like the crappy headshield I have )
With a bit of reading and practise you can get to the stage of producing welds which are 'good enough' very quickly.

[Netpackrat]

The latest revised welders handbook as an ebook ($17, cheaper as a paperback):

http://www.amazon.com/Welders-Handbook- ... lene-ebook

You can buy that book, as it is a good overview of the different processes, but a better book by the same author is Performance Welding:

http://www.amazon.com/Performance-Weldi ... 760321728/

Neither will really teach you to weld, but the latter book has more practical information, and he doesn't have to pull his punches as much because the welding equipment suppliers weren't sponsoring him to write it. I have both but the only one I still refer to at times is the Performance Welding book. Some of his advice goes against the conventional wisdom but I have found the conventional wisdom in those instances to be either wrong, or unnecessary.

As for what I would recommend in terms of learning to weld; start out with the oxy-acetylene process. It will teach you puddle control which is the basis for ALL of the manual welding processes. Once you have mastered O/A, TIG will be easy (I could basically pick up a TIG torch and run it right away after years of welding O/A). Also, even after you move on to the electric welding methods, you will want an O/A torch set in your shop because it is an extremely useful piece of kit in general. You can cut very thick sections of steel with it, you can braze with it, and for heating some parts that are frozen it's much better and faster than using something like a propane torch. With enough practice you can even use it to weld and braze aluminum. And as I recently noted in another thread, you can still use a gas torch to weld even if you have no electricity. The Russians even have a flux that will allow welding of titanium using O/A. One of my instructors has been trying to get his hands on some for years, to no avail. As he said, they will sell you parts, but not the technology used to make them.

For the electric methods, it really depends on what you want to do, and how much you can spend. TIG is more akin to a surgeon's tool. It's a bit slower than MIG or stick, but for most precision work there is nothing better; for things like tube frames, fuel tanks, special alloys, et cetera, although you can still do quality work on those items with the O/A torch, which even has some advantages in some situations over TIG.

If you mainly want to work on structural steel sections, farm type repairs, building bumpers for your off-road rig, etc. you can get a basic stick machine for not a lot of money that will do all that. It takes a bit of practice to master, but it's hard to beat for economy, and if you were to pursue a career in pipefitting, etc, it's what you would be using most of the time. In an emergency, with the right cabling setup, you can even stick weld using a couple of automotive batteries.

For a typical user, MIG will do nearly everything that stick can do, and then some. It will do it easier and with less clean up required afterward. It is far better suited to welding thin metal than stick, and IMO it is way better for auto body and most sheet metal work than TIG. You start to run into some of the limitations of MIG when you get into thin, higher alloy tubing such as in aerospace work. People will point out that several manufactures of certified and kit aircraft use MIG to weld together their fuselages, but often fail to note that those are expert welders using much higher quality equipment than the vast majority of home users will have. And they still sometimes have problems with cracking due to the nature of the MIG weld in such thin sections. Another problem with MIG is that it is deceptively easy to use. Of all the processes, its the easiest with which to lay down a weld bead that looks OK, but in reality has little strength and penetration. Buying a MIG unit that is operated with a single trigger pull is not a substitute for developing skill, although many treat it that way.

[Netpackrat]

Zen, and the Art of the Weld Puddle

[TheIrishman]

The "Certificate" would require over a year of full-time study and the Associate's Degree looks like it would take close to 3 years...What classes/certifications would I actually need to be a competent, backyard welder?

I'm a certified backyard welder I spent a few weeks every year in the welding shop of my "Vo-Tech" high school. We started with oxy/acetylene and then moved to stick. Those who were in the autobody class were required to take MIG, as it is part of the trade. O/A is not hard to learn if you are only looking to join two pieces of steel together, though quite slow, and brazing is rather simple(unless you're building an airframe). A small O/A set up and a few different torch tips will get you going, and as stated before is also great when you need to cut something up or heat a frozen nut/bolt. I have a Lincoln "tombstone" which is fine for heavy steel, but not so much sheet metal. Oddly, it sits in my cousins welding shop as I have no 220v source at home. I use a Snap On MIG most of the time for anything up to 1/8" or my cheap Horror Freight Inverter to tack heavier pieces. The heavier stuff then gets shuttled to my cousins for final welding. I would look at a portable O/A set up and a 110v stick(but not an inverter, they're portable and great for field repairs but wont hold up to "learning"). For most "around the house" welding repairs, a small stick welder will work fine. You can even buy Eutectic rods for welding aluminum and there are also rods for stainless. Will they be as pretty as a TIG? No, but the aluminum is easy to grind smooth afterward. I'd steer clear of TIG unless you plan on doing a lot of thin metals/stainless and want very clean welds.

[Highspeed]

brazing is rather simple(unless you're building an airframe)

Or on the structural areas of a motorcycle frame. Really good brazing ( plus joint design and tube fitting ) isn't at all simple.
I used to SIF bronze weld frames and the ideal joint looks more like TIG than anything else.

Going on your previous postings I suspect you know that already though

[Netpackrat]

brazing is rather simple(unless you're building an airframe)

Or on the structural areas of a motorcycle frame. Really good brazing ( plus joint design and tube fitting ) isn't at all simple.
I used to SIF bronze weld frames and the ideal joint looks more like TIG than anything else.

Going on your previous postings I suspect you know that already though

Yeah, brazing structural joints is a lot more common in the UK than it is over here. A lot of the stuff that you guys braze, we weld. Brazing of tube frame structure used to be pretty common, but it is a bad idea these days now that almost everyone is using 4130 instead of mild steel. If you go too hot by just a little bit when brazing 4130, the grain structure can open up and be infiltrated by the brazing filler. When the parts cool again it can cause cracks. It's better to use the torch to weld the joint.

As a matter of fact, while I generally use the TIG for that kind of work since I have one, if I only had an O/A torch I would have no qualms about welding together an airframe using it, and flying in it. The O/A is actually better for a less experienced welder building his own aircraft, because it's a lot more difficult to produce a bad weld that looks OK with it as opposed to TIG or (ugh) MIG. With O/A, if a weld looks good, it generally IS good. In fact, sometimes an O/A weld can look bad and still be good.

[Darrell]

You might find this amusing--Amazing Blaze welding, a short video. The site looks interesting, lots of welding tips and tricks, duh:

http://www.weldingtipsandtricks.com/ama ... eatin.html

Found via Insty.