Random thoughts on Welding

[Loren]

Apply electricity to wire, wire makes sparks and heat, metal melts and fuses together. How hard could it be, right?

I actually started out playing with somebody else's MIG welder, which was kinda fun. But, when it came time for me to buy something, I started (like an idiot) with a cheap TIG welder (which I have since sold to Joe Brannon). My thought was that TIG is essentially a lot like soldering where you have a heat source (the TIG arc) and you feed metal in separately. I've got literally decades of soldering experience, it seemed like I'd pick it up quickly. And maybe I would have if I really got serious about it. But, as a very casual hobbyist, I found that all of the consumables required for TIG (shielding gas, torch cups, electrodes, and welding rod) were a lot more than I wanted to keep up with. To a lesser degree, I felt the same way about MIG. Though you can do flux-core TIG, which is pretty much like a hot-glue gun for metal... there's still a bit of maintenance and inevitable repair with even the most basic MIG machine.

Anyway, I decided to go back to basics. The simplest form of welding. "Stick welding." You use a welding rod that is coated with flux, it acts as your electrode to provide the arc/heat, and off you go. When you're done, you have to chip away the "slag" of melted flux that is left behind. But, if you're good at it, you can weld pretty much anything. It's a little coarse and a little messy, but for the casual garage hobbyist, it takes the least amount of "overhead." You got a welder and some welding rod, you're set. Don't use it for 5 years, come back to it... you're still set. Always there when you need it. That's my kind of rig.

So, I've got the world's cheapest 110 volt, 100 Amp AC stick welder that I bought on Amazon a year or so back for about $80. It's a cute little thing, and I really like it. For small welding projects, it's great! I'm still very much a beginner with it. But, it can stick some metal together as long as it's not absolutely critical that I get it right the first time, and it's not too thin.

Last week, somebody posted up an old (1981 vintage, I learned on Google) Craftsman 220 volt, 230 Amp AC stick welder for the irresistable sum of $20 on the local Miata forum. You can find similar units on places like Craigslist all day for $150-200. But, not for $20. So, I drove out to Plant City and picked it up. I haven't even plugged it in yet, but the seller did spark it up before I picked it up, so I know it works. And it will probably still be working after I'm dead.

Now, my baby welder is theoretically capable of welding up to 1/4" steel. In practice, it's a lot happier doing small welds on 1/8 to 3/16". The 230 Amps of the Craftsman welder... that opens me up to welding, well, anything that *I* would ever need to weld.

With new equipment on-hand, and a garage full of scraps of metal and old car parts, the mind boggles at the possibilities! So, today I decided to start tinkering and just practicing some basic weld beads on some scrap. I've been refreshing myself with YouTube welding videos lately. Time to try to put some of that knowledge into practice!

Plugged in the baby welder, and went after it.

Including the 1/8" sticks that came with the big welder, I now have a pretty good selection of welding rods. So, I opted to try them all on my 1/16" thick piece of scrap. (pretty easy to blow through something that thin, btw...)

I started with the smallest, which is 1/16" 6013 rod. I bought it to attempt to weld automotive sheet metal, but never had any luck with it. Today was similar... REALLY hard to start an arc with. but, eventually, I got the current set right and was able to do some interesting stuff with it. Being so thin, you go through it REALLY quickly.

Next, I grabbed the 1/8" 6013 rod. Doesn't sound like much, but 1/8" is pretty big for a welding rod. Being larger, it takes more current to work with it. I found that I had the same problems with getting an arc started. I thought it was due to the tiny rod before... but, now I'm thinking it's just the nature of 6013. It took a LOT of current to get this rod to weld properly. So much so that I was popping my circuit breaker. (20 Amp breaker... 20 Amps x 110v = 2200W... the welding transformer cuts the voltage down closer to 24v... so when I hit 95 Amps on the welder, that's 95A x 24v = 2280W. The breaker didn't like that for more than about half a minute!) But, at about 90-95 Amps, I could actually weld with the 1/8" 6013... for as long as my circuit would hold out.

Then I went back to what has been my favorite rod for the baby welder. 3/16" 7014 rod. Super-easy to strike an arc. Arc stays lit. Restarts easily. Just all-around easy to work with. And it works well within the usable range of my welder. It doesn't take 90 Amps to get it to work. It's happy somewhere around 80 Amps. Gets surprisingly hot and blows through easily, though!

Sometime soon, I'll pull the covers off of the new welder, clean it up, and give it a go. I bet it will make quick work of those 1/8" rods and be awesome at welding big stuff. It has a "low range" that is 40-110 Amps, so it may actually be as good as the baby welder for smaller stuff. Being 220v and plugged into my dryer outlet, it ain't gonna blow the breaker, either. It will give me what I want without complaint!

Meanwhile... I'm about to swear off 6013 welding rod. I have some 1/8" 6011 to try, as well. So far, I think 7014 is much easier to work with.

There are LOTS of other welding rods to try, as well. Mostly just variations in the flux coating used, but they all have interesting characteristics. Some go for deeper penetration. Some go for high deposition of weld metal. Less weld spatter. Usable in different positions (like overhead, or vertical vs. horizontal).

I just need to make myself go out to the garage and play more!

[AScoda]

Always wanted to weld, but I can count on one hand the time where I could have used the skill and equipment. I think most of those few times have also been aluminum, which requires more than your basic welding skills as I understand.

[Loren]

I did some looking into welding aluminum. I'm not ready to try it yet, but you CAN stick weld aluminum. It's not the preferred method, and it won't be as pretty as a TIG weld, but it can be done! I think it may require a DC welder rather than the cheap AC welders that I have, as well.

I need to develop at least a meager level of "mastery" of welding steel before I think about aluminum.

Oh, and if you HAVE a welder, you'll find a lot more uses for it. Welding together broken this or that. Fabricating and welding a nice bracket where you might have done with a zip-tie before. Stuff like that.

[Loren]

Heh. Was just watching another video and realized that I said I was using 3/16" rod above. It's actually 3/32". 3/16" would be larger tahn 1/8" (duh!). I definitely don't have anything that big.

And I've come to the conclusion that most of my practice has been on material that is way too thin. It's someting that I want to be able to do, but it's NOT the best way to start! To pull it off, you have to be good enough that you can move QUICKLY without losing your technique. In my case, I can't move that quickly... so, I blow through the material. Thus I turn the amperage down, and get into all the pitfalls of not enough amps.

I need to scrounge up some thicker scrap for practice. I wonder if I can run beads on a Festiva engine block?

[jbrannon7]

I wonder if I can run beads on a Festiva engine block?

Cast iron doesn't weld well, but there should be plenty of steel in the engine to play with.

[Loren]

I wonder if I can run beads on a Festiva engine block?

Cast iron doesn't weld well, but there should be plenty of steel in the engine to play with.

Yeah, connecting rods, crankshaft, camshaft, pressure plate. Lots of steel bits.

[Rawkkrawler]

I’ll be looking for some nice flywheel/connecting rod/camshaft/piston yard art next time I’m over!

[Loren]

Idunno about "nice", but I may have some crap scabbed together in strange ways!

I gave the "new" welder a look last night. Found out that the plug that's on it doesn't match my dryer outlet. And I decided (okay, I really decided this when I first saw it) that I don't like the idea of using solid-conductor builder-grade wire as a flexible cord. No idea how long it's been in use that way (looks like a LONG time), so I don't know how many times it's been coiled and uncoiled, or when one of those conductors is going to decide to break and start causing me problems... such as fire.

So, I ordered a proper 10' dryer cord, and I'll wire that up.

Oh, and I ordered some 7018 welding rod. Everybody, and I mean everybody, says that 7018 is the shit. I'd been shunning it because it's supposed to require special handling... and it does, IF you are doing critical structural welding with it. But, I'm not. And I found plenty of people claiming to use the stuff regularly "around the shop" for general purpose use without giving it "proper care".

I did order a sealed welding rod container to put them in. That will help keep them from absorbing moisture, and should keep them plenty happy for my purposes. I ordered it in the 3/32" size, so I can use it with either welder.

Can't wait to try it!

But, I've also got 5 pounds of 1/8" 6011, and 5 pounds of 1/8" 6013 to burn up. Lots of welding rod to practice with.

[Blue_Heron]

I've been stick welding since metal shop in high school 40 years ago. When Tyler graduated high school in 2010, we took a community ed welding class at the local community college and I was introduced to MIG for the first time. After the class, I went out and bought a Millermatic 185 MIG welder. I also picked up bottles of Argon (for aluminum) and mixed gas (for steel and stainless).

The Millermatic has a dummy mode where you set the wire thickness and the thickness of the metal you're welding and the machine automagically sets wire speed and amperage. It's DC, so you use reverse polarity on Aluminum. It is the bomb for anything from 18ga sheet metal to 1/4" steel. My stick welder ( a DC Miller machine) sits in the corner gathering dust. Lincoln and some others make similar machines.

MIG makes it so much easier to strike an ark. It makes such pretty beads with no slag to chip off. You don't have to adjust your hand position to compensate for an ever shortening electrode, I can't imagine using a stick welder for anything thinner than 3/16" but your mileage may vary. It's fun to play with a welder no matter what kind. But the right tool for the right job is a thing, too.
Dave

[Loren]

I definitely hear you about the right tool! That's why certain jobs will always go to someone like Joe with better equipment and more experience.

I figure if I get reasonably good with stick welding, the basic skills will translate to MIG later on if I need it.

[Blue_Heron]

I figure if I get reasonably good with stick welding, the basic skills will translate to MIG later on if I need it.

True enough. Welding with an AC buzz box is like autoXing on all season radials.

[Blue_Heron]

If you don't already have an auto-darkening helmet, these are a good value:

https://www.harborfreight.com/welding/w ... 46092.html

They go on sale from time to time. Once I had one, I wondered how I ever welded without one.

[Loren]

Yeah, I actually have two of them. One has a wonky strap. They do make the process of welding much easier!

[Loren]

Took apart the ol' Craftsman welder today. 28 damned screws holding the cover on that thing!!!

Very basic inside. Power switch, transformer, and output jacks. That's pretty much it!

Caution -- Geeky electronics stuff ahead.

I never gave it much thought. If I had, I'd have probably expected this. I sort of thought that the variable amperage control in an AC welder came from some sort of a rheostat or potentiometer or variable resistor of some sort. That's they typical to way to vary power output. But, on a high-power device like a welder, it would have to be a VERY heavy-duty resistor, and ultimately, it would just become a heating element and burn itself up.

No, the actual solution is far more elegant. The welder uses a simple transformer to convert high voltage (220 Volts), low current (30 Amps) AC to low voltage (~24 Volts), high current (up to 240 Amps) AC. To make the output current variable, the transformer uses multiple output windings and a movable iron core to control the electromagnetic flux that is applied to each secondary winding.

A picture is worth a thousand words:



And that's all there is to it. The amperage control on an old-school transformer-based AC welder is purely mechanical. No contact points at all! That, plus the fact that the transformers are very beefy, is why these things tend to last forever.

[blacksheep-1]

Absolutely get an auto darkening helmet, just for the ease of use, starting to weld, then having to rock your head to drop the visor is a PITA.
Also, it might pay to take a welding class at your local vocational school.

[Loren]

Did some cleaning inside the welder today, got the new cable installed and gave it a quick test run. It fires up, fan works, and it will make an arc. Couldn't get a good bead with the leftover piece of 3/32 rod I was playing with due to an interesting trick of physics.

I mentioned above the movable iron core used in the transformer. Well, I was testing things with the cover off. Hate to button it all up just to find out something is wrong and have to take it all apart again. Cover off means that the amperage selector knob thingy is not present. It's a rotating/sliding kinda deal that (worthy of note!) locks into position when you tighten the knob. I thought that was a curious feature, maybe due to vibration or something? But, why would it move? Probably won't move. Right?

So, I'm testing. Power it up. Fan sounds good. Little bit of transformer hum. No smells, no smoke. But, as soon as I go to strike an arc, THWACK! The current through the transformer acts like an electromagnet and flings the movable core shuttle all the way to the minimum current side. So, all of my testing was done at 40 amps.

Anyway, it works. I opted to do a little bit of paint work on the top plate where it was significantly rusty. Didn't feel like fully disassembling to do a full repaint. I just knocked the rust off of it, taped off a nice line, and hit it with my favorite can of hammered copper Rustoleum. Should protect it for a few years. Maybe someday I'll do a full refurb on it.

Once the paint is cured, I'll put it all back together and get it back on the cart. Need to do some work on the cart, too. I bought a new set of lawn mower wheels ($3 each on Amazon!) for the cart to replace the very flat sided (more than a flat spot, doesn't roll worth a damn) old recycled tricycle rear wheels. Will fit those and maybe do a little clean-up on it. It's galvanized steel, so doesn't need paint. But, it's got an awful lot of sharp edges that I might round off with the angle grinder. And I'll put some proper cord hangers on it and stuff to make it more usable.

[twistedwankel]

The strongest weld I ever did was putting my Sear's ridamower back together at the farm. What really pissed me off was that the welding cart fell apart and I had to weld it back together. The gas is rather irrelevant with the flux wire. I weld for shit but it stays together better than Chinamerica. Keep the surfaces clean. Use the anti blind helmet.