Welding and Metalworking - Building an Arc Welder - Would like help.

Hi all.


I'm going to try and build one of those microwave transformer arc welders. I realize its dangerous and if I lick the wires and attach them to my nipples I will probably be in a world of hurt or no longer in pain at all but I'm gonna give it a shot anyways.

I'll probably have several questions as I get going on it so I'm going to start a post. I couldn't find any posts on doing this here so if I missed it please link me to it.

I have a very small amount of electrical knowledge. I've wired ceiling fans, and installed RV and dryer plugs, wall outlets switches and wired my shop (only for lights and 15 amp plugs though) but I really don't know much past that right there. I took physics back in college but that was 8 years ago and we probably only spent 3 weeks on the whole ohms law thing anyways.

I'm mainly following the instructables.com post here (http://www.instructables.com/id/Build-a-Microwave-Transformer-Homemade-Welder/)
for the basics but I know with everybody's help here I can do a better job with it.

So far I have 2 microwaves ready for ripping apart and a massive transformer from a forklift battery charger, and a power supply for an old pipe organ that I really don't know how it works or even if it matters for this discussion.

I'm at work right now but I plan on having photos of everything as I go posted for folks to look at and say "thats not how you do it . . . idiot."

I know this is going to be lots of fun for me, but I'm really hoping to get some actual smart folks in on the job too.
so if anybody is up for it have a read at that instructables post and see what improvements I can make on it.

thanks!

chris

I've seen a couple of DIY tig welder projects on the web, and their downfall seems to be they have no foot pedal for arc control.

If you're thinking of a stick welder, it seems like buying one used off CraigsList.org would be a safer bet.

If those web projects work at all they're probably built by a guy who has a lot of relevant domain knowledge, who has the experience to solve what will to the layman be difficult problems.

It would definitely be cool to point at it and say "I built this out of junk parts and it works", and who wouldn't love to have a tig welder in their shop. But practical reality for most people is "buy a tested, engineered, ready-made machine that comes with an owner's manual".

I agree plus I am not sure how much help we can be.

A project like this could likely be done but not with step-by-step instructions from a forum like this.
I realize we are a diy forum but this is pushing the limits of what a person should do without at least a little prior knowledge, especially in electrical safety.

A hundred bucks will buy you a used little 120 volt buzz box that will allow you to make sparks in places where they should be made.

I have built power supples from old transformers but I have never used one for arc welder. The last microwave tranny I junked had 120 volt in and 4100 volt out and either end could have been fatal if you screw with it. I also notice that the windings that looked like copper were actually copper coated aluminum wire. I have never seen anything like that before.
As GregH said you can pick up a second hand one that will be ready to go for 60 to 100 bucks.

This is clearly a high risk endevor due to the number of unknowns. The components were engineered to work for an entirely different purpose, thus exhibiting unpredictable behavior in the new use.
Even if every responder on this forum WERE a rocket scientist, much gets lost in the translation to a forum format. What you observe may be ignored or misinterpreted as you describe the system behavior.
If you want to weld, go get a welding machine. If you want to play with high voltages and radiation under the guise of making a welder, well, we cannot stop you. It is likely that you will stop yourself. Try not to get hurt too bad.