Home made AC stick welder!

This is pretty crazy, but it seems to work. These guys made a AC stick welder using old microwave parts and some copper wire. It looks totally crappy and I would be afraid of getting testicle cancer or something. The welds don't look too bad though.
I think this would be a fun project. I would put it in a case though.
http://www.instructables.com/id/Build-a-Microwave-Transformer-Homemade-Welder/

Does anyone who has electrical experience see anything wrong with it? Will it be safe?

 

I guess they call it "The Shocker"

 

the 4wd guys make em using an alternator so they can burn the parts they broke back together to get back to civilization

 

wasnt that alternator one a tig welder ? i saw a post on a mustang forum a few years back about that one made with a battery jump start pack and 90 amp alternator and cheap mig torch some guy was welding ss with it ,

 

I think Sir Isaac Newton will have something to sat about that rig.

 

put a bulb across the output when you unplug welder it it should flash. If so do not operate without functional bulb or deliberate shorting strap. you'll have to play with possibly two bulbs in series.

 

heres one


the original threadhttp://www.theturboforums.com/smf/index.php?topic=8872.msg682907#msg682907

 

I think Murphy has a law that covers that. But Rube Goldberg has the patent.

 

Easy, all you need is a set of jumper cables...

 

my friends grandfather made his own stickwelder back in the 1930s
he couldnt afford to buy one so he built his own..... haha...

 

Two words.....Tesla Coil.....Just go bigger with what you have and you could weld from across town.

 

i'm an electrician and there is no way in hell i would do that. that's a good way to kill yourself with what they are doing.

 

Please explain how. I am not saying you are wrong in fact I would have to agree I just don't know why!

 

All jokes aside, I'm an electrician also and it looks like you stepped up the voltage twice with your two transformers. You could easily make that circuit with your body. Welders have protection from shock and what you have may not. Send it to my ex wife in Omaha labeled "hair dryer".

 

When I was a kid, I bought a little junky "welder" from the back of a Popular Mechanics magazine I think for around $12.99 or something (which seemed like a fortune back then). It was just a metal box with some criss-crossing resistance wire to knock the voltage down a little and maybe some diodes. It plugged into a 110 V outlet. I don't think it had a transformer. So it probably put out 15 amps max. It made sparks and little burn marks on things, but I don't think I ever made anything that looked like a real weld. It came with a handful of stick electrodes and a gizmo with two carbon rods supposedly for doing some sort of arc gouging or brazing or something. It did make an arc and some smoke, but it was hopeless trying to do anything useful with it. I think I might still have that thing in the attic somewhere. What a waste of $12. I probably had to mow 24 lawns to get that kind of dough. You think stuff from Harbor Freight is junk, some of the junk you got through mail-order places back then was even worse.

 

Aren't stick welders like $100 or less?

 

so two step-up transformer's,with the secondary windings wired in series to boost the voltage...i don't think is gonna nuke ya but it looks un-safe as hell.arc welders are cheap these days,you only get one shot at getting it wrong

 

Actually, I think that they are stepping down the voltage. Which is what you want for arc welding: low volts, high amps. That's why the secondary windings are large gauge wire.

Microwave oven transformers probably step up about 40 to 1. 120 volts to 40,000 volts or thereabouts IIRC, and the secondary insulation withstands that large a voltage.

If you connect that backwards, you reduce voltage 40 to 1. You have overkill in terms of the secondary (now primary) insulation dielectric strength, and you have around 3 volts coming out.

So this is very doable.

Of course, 3 volts AC with the current that can come out (voltamps hi = voltamps low; if the 'welder' was drawing 1 amp on the high side you would have 40 on the low side) will absolutely get your attention, so all safety practices should be followed.

 

Ya you are probably right, and that would explain higher amperage welders and not high voltage welders but power is power. The two are multiplied
together and I would not want to be part of the circuit.

 

Yep. Also, in response to someone who was worried about frying gonads, not unless you kept the Klystron tube (which is what requires the 40,000 volts). That's what makes the microwaves.

 

Klystron tube? Is that what made time travel possible for Marty and the
Delorean? J/k no disrespect just trying to bring this thread back to cars.....or end it......if the welder guy isn't dead already.

 

LOL that's what they are called. There is a pretty nice home made tool thread going on; maybe the home made welder belongs there. With a flux capacitor.

 

Come on Guys. Traditional Hot Rodding is what we are about. Building things to learn about the craft. The Microwave transformer has a seperate primary winding and a seperate secondary winding. You knock out the High Voltage seconday and wind as many turns of #4 welding cable you can fit where the old secondary was. The secondary open circuit voltage would be less than 10 volts and you could pull 100 amps. Two transformer primarys in parallel 115 volts(correct phaseing) and two secondarys in series would work. Open circuit secondary volts around 20 VAC. The power factor is very poor for this setup and would pop a 25 amp breaker when you had a heavy arc going. Two primarys in series (correct phaseing) and 220 volts would be a better set up. Very similar to a 100 amp buzz box. Sure you could buy a welder,but we make a lot of stuff we could buy. Also a Kylstron tube is different than a cavity Magnetron tube used in microwaves.

 

I guess in Cuba they just hook right into the electric line to arc weld, and use wire from chain link fence as welding rod. Compared to that, this almost seems safe.

 

Wait a dang minute! Re Popular Mechanics $12 welder
I had one of those for years, never had a seconds trouble with it. It was no Lincoln 225 but it worked perfect. made motor mounts , an engine hoist and all kinds of small stuff aswell. used to weld small stufff for my motorcycle pals. You need the small rods (1/16) When you 16 years old and pumping gas at 35 cents an hour it was all you could possibly afford. Where did the North American spirit of experimentation and enterpise go. Sometimes i think it fell on 911 as well. When i was drag racing a few years ago with my nephew he said once. "Why do you make everything when we could buy it?" I was absolutely floored. i had mistakenly thought that was the great attraction of the hobby. I am also a Ham operator (VE3LYX)and we used to build transmitters with 3000 to 5000 volts DC at decent amperages too. up to 2500 watts. You have to be careful for sure but a 28 volt welder will have to work pretty hard to zap you. Two tranformers or twentytwo makes little difference. I applaud the spirit of invention and those who take the time to try. I am sick of cruise nights with 40 boughten hot rods , racers with $28000 dollar motors and $9000 dollar trans all racing for the same $500 bucks I am and whining about how it is unfair to have to race us since we havent spent the gold they have. Tis a bad year when you cant make something. I made a dragster. several manifolds, a battery charger, an electrolysis cleaning tank, several violins and even remanufactured some pistons from usable cores for a 426 cube stroker motor that ran 10.40s in an 82 Mirada. Surely that part of the hobby life should not be extinct. Saw one guy who had the alternator tig welder attached to his air compressor and drove from the same belt. I admire this type of inovation and hope it never stops.
Fact is homemade welders as well do work. Voltage is not high, amperage is, although I do agree one hundred percent that it should be in a box and not sitting on the table like that. If it is grounded and fused it is fine.

 

And you read a schematic with two transformers in parallel and think that will step up the voltage? Who 's joking who?

 

Electricians are into delivery. They never make the pizza. Still we need them desperately but ???????? well, you know.

 

I believe I'll stick to store bought welders.

 

Hey, not all of us electricians are like that. I'm an industrial electrician......which means I have handled live 480 without a flash shield and 2 layers of gloves. Yep, I survived.....no ground path.

Amps kill you, but voltage is what gets it into you. Ever shock yourself with a car battery? I haven't, but I managed to weld a steel crescent wrench to an aluminum alternator case pretty effectively about 21 years ago. The low voltage has a very hard time breaking through the body's natural resistance. That same low voltage, given enough current, is an electric welder.

Anybody know where to get the diodes to turn an AC rig into DC? I'm too lazy to look...................

Tim D.

 

Thanks for clearing that up for everyone GOOBs