Cheap homemade welders compared: AC stick, DC stick, DC spoolgun. Oxyfuel discussion.
Welding is usually the easiest and quickest way to build something.
You just put the parts next to each other and weld them.
You don't have to drill bolt holes and go to the hardware store for bolts.
Metal doesn't split like wood. It doesn't have grain and knots that make every piece different.
You can get all kinds of scrap metal for free. Bed frames, parts of old cars, etc etc.
And you can make your own welder for free or close to it.
Don't have access to a welder? LIAR!! All it takes is some junk car batteries and a welding rod.
Or some dead microwave ovens to butcher for the transformers.
Make your own industrial revolution!
Make these welders yourself!
AC stick welder,
DC stick welding with car batteries
wirefeed spoolgun with car batteries
Solar powered battery welder
This instructable is my "table of contents" for welding projects. When I do more projects I'll add more steps here to link to them.
Step 1: Welding With Books!
The most important welding tool is... INFORMATION.
Whenever I screw up a weld, I go look up how I should have done it. Sure enough, there's a proper polarity, current, feed rate, shielding gas/flow rate, flux etc for the weld. I do it that way, and suddenly I'm a great welder.
No matter how many welding books I get, I need them all. There's some kind of Japanese-style collusion between publishers to distribute the information between all the books. None of them have all the information you need. Every book will add a lot of information the others don't have. They also tend to devote a lot of space to info you'll never need, like how to weld train tracks using an automated submerged-arc machine.
The Miller online welding calculators are really good, especially for something like TIG that has 5 or 6 different parameters.
Step 2: Don't Poison Gas Attack Yourself, Etc.
Welders don't live very long.
Smoke including welding smoke is usually full of some poison or other.
Manganese poisoning is one of the hazards, especially if you do a lot of welding in confined spaces. Wear a respirator with the proper filter.
Or make your own, 1942 style!
New Zealand has a great online manual on welding safety. The number of ways to harm yourself with welding is truly amazing. I took a welding class once. It turned out I'd been doing some really dangerous things. Lets say you need to arc weld a distance from your welder. So you carry a coil of cable. If you weld with that coil of cable around you, you can stop your heart with an induced current.
Step 3: AC Stick
Cost: $0 and up.
see the entire DIY AC Stick Welder Instructable.
It costs nothing to make. The junk you need is probably already in your alley or garage. A bundle of rods costs $7 or so anywhere in the world.
It's much easier to make this welder run on 220 volts than on 110, since it draws half as much current on 220 and your breakers are less likely to blow.
Striking an arc without sticking the rod to the work is a skill, look for some instructional videos on youtube. I do it by listening. It makes a particular sound when you do it right.
It's very easy to weld on steel that's about the same thickness as your welding rods or a little thicker.
For thinner walled stuff it takes some skill and looking up the proper settings.
Stainless is also easy to weld with this unit. Just get some stainless rods at the welding store. Use low power and thin rods, stainless is a poor conductor of heat and it's easy to melt through. But it's easy to make it look nice. It's "stainless" so it's easy to make nice shiny welds.
They sell aluminum rods also, but I've never gotten them to work for me.
Step 4: DC Stick
Weld Steel and stainless steel
Cost: $0 and up.
Another welder that's already laying in pieces in your alley, car, and garage.
see the entire DIY DC Stick Welder Instructable.
A few old batteries can deliver awesome amounts of current.
Combine 6volt and 12 volt batteries to get any voltage you need. I've never needed more than 36 volts.
I've done some really heavy welding with batteries. I've also cut holes by dipping the rods in water first.
For stainless, you can wire it electrode positive so most of the heat goes into the rod rather than the work. It's harder to strike an arc with this DC unit than the AC one. The AC unit has a higher "open-circuit voltage". Batteries are a "voltage source" and the arc is much shorter than with a "current source".
Step 5: Solar Welder
Here's my Solar Powered Welder project.
Pretty much any alternative energy project will include something that will make a fine welder.
If you're living in an off-grid house with a battery bank, you've got the most powerful welder ever made!
Step 6: Battery Spoolgun - Flux Core Wirefeed
Cost: $75 and up.
see the entire DIY Battery SpoolGun instructable.
Wirefeed is very easy to use. A lot like a gluegun. Just point it at the pieces you want joined and pull the trigger.
Flux-core wire means you don't need a shielding gas cylinder. The fluxcore wire I've used has deposited very thin slag. Not much work to brush it off. Fluxcore wire costs $4/lb and up.
Cheap fluxcore wirefeed welders are abundant in hardware stores and used on craigslist.
For even less cost on ebay you can get a spoolgun and run it on car batteries. Old car batteries will put out as much current as a very expensive welder.
Control welding heat with distance from the gun to the weld. Close in is a short low resistance wire - more current and heat - melt it in. Further out - longer wire - more resistance - less heat and a puddle that builds up higher.
To weld stainless steel and aluminum you'll need shielding gas.
For ~$200 you can add a gas cylinder and regulator.
Different materials require different shielding gases.
Thin walled materials such as tubing require skill.
You must look up wire diameter, feed rate, and voltage to get a good weld and not burn holes.
You must look up and do everything exactly right to weld aluminum.
Step 7: Oxy-Acetylene (Oxy-Fuel)
Weld Steel, stainless steel, aluminum. Braze anything. Really good on sheetmetal, thin tubing, and rusty stuff.
Cost: $200 and up.
A lot of people have a set of tanks around just for cutting. They don't realize it's their best welder for a lot of jobs. Put your smallest tip on it and it's easier to use on thin tubing and sheetmetal than any other welder I've tried. You can use coat hangers and random wire for filler rod.
Acetylene isn't the only fuel for this, you can use propane, hydrogen, or pretty much any flammable gas. Acetylene has the hottest flame. Get the free manual for gas cutting/welding from the welding supply shop. It has tables for what size tip and pressure to use for what fuel. And what thickness of what metal you're working on. Like all other welding, checking the book first makes your welds beautiful.
I just gas welded a stainless steel ladder from tubing. I used stainless bicycle spokes from junk wheels for filler rod. Now I want to make a whole lot more stuff like that. You don't need a helmet or gloves, just a pair of welding goggles. It's really quiet.
At Oshkosh they teach people to weld airplane frames and aluminum with oxy-acetylene and oxy-hydrogen. It's a really sociable type of welding. It doesn't drive people off with UV, fumes and noise. For aluminum you use some white flux to paint on the area before heating.
We used ESAB #35 aluminum flux and Alcotec alloy ER1100 3/64" welding rods.
TM tinmantech Aluminum Premium Flux also.
Muffler shops, even the big franchises use oxy-acetylene for patching pipes. You can adjust the flame to "reducing" with a shortage of oxygen. The starved flame turns rust back into steel.
Stainless will rust unless you treat it right. You can't use a steel brush or an old grinding wheel that's been used on regular steel. That will rub rustable iron onto the surface. Get a fresh grinding wheel and only use it for stainless. After welding you need to "passivate" the stainless. Rustable iron crystals come to the surface of the weld. You need to clean your weld with something - not steel wool, not steel brush. I'm using a bronze brush. Then use lemon juice to etch all the iron off the surface. The chrome and nickel that remains won't rust. Unless you mix grades of stainless, or have an electrical problem, or....
But don't worry about that stuff for now, it'll still rust a lot slower than regular iron.