I'm copying this from another forum. I have no idea whether it is safe, the poster says it originally came from Popular Mechanics magazine. Any opinions?
His words..
"I will post this 1 more time! To loosen stuck bolts/ studs/screws in aluminum/ steel/ cast/anything else. Get 2 visegrips and a BIG battery ( don't waste yer time with some battery charger)and some jumper cables. You clamp 1 of the vise grips to the stuck bolt/ stud/screw very tightly on a shiney part so you got a good connection. The other vise grip you clamp very tightly on a close by ground( don't clamp on a rear brake bleeder and use the stock ground in the front). you connect both the jumpers to the battery and the other end to the stuck bolt vise grip. then the fun part, you QUICKLY clamp the other remaining battery jumper to the ground and there will be a BIG spark!. Wait 2-3 seconds and take it off and try to wiggle the part, if nothing happens try again. it will eventually loosen the part, because corrosion has more resistance than good clean metal. and you will blast the rust/ oxide out with the maybe 4-600 amps you are putting thru it.Sometimes there will be a small puff of smoke.It doesn't seem to make any dif on polarity. I have been doing this for 50 years since I read about it in Popular Mechanics. It works great on brake bleeders, stripped carb screws,chevy manifold bolts, Honda case screws,Cade manifold bolts,anything like that. Spare me all the warnings about batteries blowing up and starting your house on fire, I'm assuming if you are ass deep in a Cade you have a little brains, and you won't connect it and walk away to mow a lawn, we are talking seconds here, no more."
His words..
"I will post this 1 more time! To loosen stuck bolts/ studs/screws in aluminum/ steel/ cast/anything else. Get 2 visegrips and a BIG battery ( don't waste yer time with some battery charger)and some jumper cables. You clamp 1 of the vise grips to the stuck bolt/ stud/screw very tightly on a shiney part so you got a good connection. The other vise grip you clamp very tightly on a close by ground( don't clamp on a rear brake bleeder and use the stock ground in the front). you connect both the jumpers to the battery and the other end to the stuck bolt vise grip. then the fun part, you QUICKLY clamp the other remaining battery jumper to the ground and there will be a BIG spark!. Wait 2-3 seconds and take it off and try to wiggle the part, if nothing happens try again. it will eventually loosen the part, because corrosion has more resistance than good clean metal. and you will blast the rust/ oxide out with the maybe 4-600 amps you are putting thru it.Sometimes there will be a small puff of smoke.It doesn't seem to make any dif on polarity. I have been doing this for 50 years since I read about it in Popular Mechanics. It works great on brake bleeders, stripped carb screws,chevy manifold bolts, Honda case screws,Cade manifold bolts,anything like that. Spare me all the warnings about batteries blowing up and starting your house on fire, I'm assuming if you are ass deep in a Cade you have a little brains, and you won't connect it and walk away to mow a lawn, we are talking seconds here, no more."
