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Guest cryslr
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Guest bythesea

MacGuyver did it with a nickel for the rod. Yoou could, I suppose, either connect the batteries in series(for 24 volts) or parallel(for more amp reserve). I'd go for the series. One (+ )conected to one (-). Hook the other negative to the work and put the rod to the remaining positive. I'd also be a chicken and cover the batteries just in case. There are any number of cheap rod welders on the market though and a small mig is even pretty cheep. The main questiopn being what you want to do with it. Low amp machines are rathere limited in the size stock they can handle. I have a Chicago Electric Power Mig 170 from Harbor Freight which does well on light stuff and I run it off my 5500 Watt generator. It works best with the inert gas kit. For steal you want to use 75% CO2-25% Argon mix. Don't try straight Argon on steel as it will inhibit the weld and give really poor penetration, And it melts tips something fierce. You will want the Argon for Aluminum and Stainless though. I bought a second bottle rather than have to keep dumping/filling when I switched metals.

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Guest Bill Putney

Batteries give off Hydrogen Sulfide gas when being charged - a highly explosive gas. The reason you should *always* unplug a battery charger (from the a.c. source) before disconnecting it at the battery is so it won't generate a spark and explode (the whole battery explodes throwing shrapnel and sulferic acid all over you and everything else). This isn't just an urban myth - it's real - it happened to my dad (fortunately he wasn't hurt).

 

I think bythesea's suggestion to cover the batteries was due to this explosion potential. This would be a real concern in my mind - but maybe only if the battery is on a charger just before you strike an arc?

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Guest bythesea

Yup Bill,

That was part of it. Also just the potential for rapidly heating the batteries with the heavy draw and splitting the cases from the expansion of the electrolyte. I don't really recommend the idea though in general. Also there a few DC welders available on the market meant to run from a vehicle. I wouldn't imagine the batteries giving very consistant penetration. I bet they'd either just scratch the work or if it was light metal they might just vaporize it.

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Guest lenhorn

Last summer WAY out in the Nevada desert I came accross a guy in an old Willys wagon (a very trick Willys wagon)who was doing a welding repair on the small trailer he was pulling (made from a Willys pickup bed). He had an onboard welder and also a power inverter that he ran a 110v 4" grinder with and he was repairing a spring shackle. He had installed a 140 amp alt on the Chevy smallblock in the Willys to power the welder. I stopped to help the guy out and it quickly became obvious he knew how to weld. He prepped the weld with the grinder and burned in two passes of 8018 rod and when he was done it looked as good as any welds I've seen anywhere. I'd love to have one on my Suburban but I'd rather spend the $800 on the Subaru.

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One thing not covered is the diff between the old stick welder "buzz boxes" and newer MIG and TIG units.

The old units are AC machines and the newer are DC machines capable of changing the flow of current from the work piece to the torch (gun) or visa versa. This direction of the current flow causes a variety of things one of which is depth of penetration of the weld into the surface - see your welding specialist for more details.

 

MIG welding (Metal Inert Gas) has a gun that has a trigger for turning on the power( read arc voltage) and at the same time turning on a motor that feeds the welding wire through a hole in the end of the gun's barrel, this is accompanied by a release of a shielding (inert) gas also expelled near the end of the barrel.( Inert gases for the chemically challenged is a substance that will not react with anything, this is due to the outer shell of it's electron cloud being in a "happy state") This shield prevents the build up of oxides and other pollutants that can cause porosity in a weld and make it weak. The inert gas(bottle/regulator/on- off solenoid) can be substituted by using "Flux Core" welding wire which has a core that vaporizes and shields the weld.

 

TIG ( Tungsten Inert Gas ) Is an entirely different beast. More akin to brazing or gas welding except the heat of the weld is produced by electric current rather than burning gases, this heat is much more intense and controllable by foot pedal or a small figure operated wheel on the torch. The operation goes something like this- Bring the torch close to the grounded work piece- step on the pedal -shielding gas flows out of the torch end and a hi freq. voltage is presented at the torch tip which establishes the arc- once the arc is established the hi freq. shuts off and the current reverts to straight DC( except on AL the hi freq. stays on). This intense arc produces a plasma hot area that melts the work piece- now with practice some work pieces can be fused with no other material needed but in most cases a filler rod ( of the same material being welded) is introduced into the puddle of molten material formed by the arc. Real good TIG welders can weld beer can thickness materials,( I have heard -never seen- that they can weld cig pack al foil- phewie) the weld is VERY clean and professional looking when done right.

WHERE's the TUNGSTEN? it is the very tip of the torch and needs ground to a sharp point or rounded ball ( depending on the work mat.) It can with stand the extremely high temps encountered with out melting. But if "OPPSed" into the puddle must be removed and resharpened to remove mat. and establish a good arc point

 

 

May I add to this extremely long diatribe that for novice welders- stick- MIG or TIG the best thing to get to assist you in performing the operation is a good helmet- the glass comes in different levels of "shading" and will let you "see" the puddle formed by the process you choose. Arc flash is a very bad thing to encounter- makes the eyes dry out( you'll lose allot of sleep) and can cause other very serious consequences- do not let it happen to you.

 

THE BEST thing since sliced bread is the new line of "Speed Glass" helmets these have an electronically dimmed glass that when there is no arc present turn to a pair of sun glasses shading- immediately upon drawing an arc they dim to the level of shading you choose ( This level like a normal helmet is chosen at the time of purchase, but the normal helmet has a replaceable lens and cover glass) Cost for one of these beauties- bout 2 or 3 C-notes.

 

Please forgive the length of this post and if there are any inaccuracies please point them out.

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Guest Witte

There is a HUGE difference between a Good stick welder and the Cheap buzz boxes you find in stores.

 

The good stick wleders can even be used to run Tig setups, power wirefeeders, etc. Where as a buzz box is lucky to make a good enough arc to make a decent weld.

 

Mig is likely the best for Hobby or rapid production where perfect welds are not critical

 

Tig is Great for high precision, high strength welds. Also many exotic metals are currently only possible with tig.

 

Gas is great for delicate work, and needed for brazing.

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Guest Bill Putney

Thanks for the education, Skip & Witte - I didn't know all of that previously - very informative.

 

BUT, would I be correct, Skip, in saying that your warning about the eyes was way understated? My understanding is that looking at any of the arcs (or even a brazing flame) can/will burn the retina (maybe cause cataracts from lower-level repeated exposure) and possibly cause permanent blindness (even for observers from a distance) in much the same way that looking at the sun can? (I believe it is primarily due to the UV content.) It has always been my practice when walking through an area where welding is going on to *never* have a welding arc (or brazing flame) *anywhere* in my field of vision - I generally put a hand up to my face to act as a shield as I walk through no matter how stupid it looks. Am I being paranoid? This was drummed into my head by my dad when I was a kid working in his mechanical contracting business (or maybe he overstated it knowing that a kid is going to believe only a fraction of what he's told - but this particular thing "stuck").

 

I would think that the intensity and danger follows a square (or is it 4th power?) law - i.e., the intensity on the retina would be 25 times greater for, say the welder, at 2 feet away as it would be for an observer 10 feet away.

 

If my information is incorrect, someone speak up.

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Guest Witte

The UV is a real killer, but the non-UV radiation will toast Eye-balls too. The best thing to ever happen to welders was the invention of cheap 100% UV coatings. Trust me If you acedently look into a arc with a pair of 100% UV glasses on it hurts a hell of alot less. Also it makes the helmets safer, as it lets you use a slightly lighter tint with less danger.

 

Best idea is no not even look in the direction, and avoid looking at the reflection. The only truely safe way to look at a welding arc is through a camera.

 

Oh and NEVER use welding goggles unless you like radiation burns. Use a full helmet, decently thick long sleeve shirt, and long pants. Denium is best for both shirt and pants.

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Guest bythesea

One must to add to Wittes list is GLOVES. Not cheap shorty ones , but real forearm covering leather welders gloves. Spatter from a MIG is suprisingly hot. Hot iron burns are exceptionally nasty and painfull. I last made that mistake about 18 years ago and still have a neat scar to prove it. A nice welders cap is also a good idea since most helmets don't cover the top of your head. They are available in a variety of silly patterns. I got my self-dimming helmet at Napa for about $220.

 

PS Never carry a Bic type lighter while welding. A piece of hot slag can turn one into a very effective hand grenade. Picture one in your left breast pocket and you'll get the point. It may be Urban Legend but theres a story of a welder at Electric Boat in Groton, CT, blowing a nice hole in his chest with one.

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Guest Witte

Damn, forgot the gloves. Welding gloves are not required if you are careful, and only doing ultra light work. However welding gloves are dirtcheap and avalible at wallmart so there is no excuse for not getting them. The first time you pick up somehting you have been welding on for 10min with a normal pair of gloves you will be REALLY wanting that cheap pair of welding gloves. Trust me on that one.

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Bill your paranoia is warranted. But I don't think at distances of 20 feet or so you will experience "getting flashed".

Just leave it to say NEVER look at a welding op with the naked eye. The dark glasses Witte mentions are for gas powered brazing, silver soldering and cutting and and never should be used for any electrical welding op.

BUT an old wives tale was dismissed by my optometrist- the subject of contacts getting "welded" to an eyeball is false.

When I ask him about this he presented documented proof that the story had been falsified by the person in question. This document was directly from the trial.

And covering body parts when you are welding- a TIG welder at my plant tells tale of one summer when the ambient was around 80 F. He had his shirt open, now TIG welding produces no slag or bits of hot matter flying about, but he got a sunburn like he had never had. I've seen guys arms above their gloves red as beets.

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