<VV> Unintentional Welding (no corvair)

[Bill Elliott]

With all of this info about welding, I thought I would share with you a bit of unintentional welding I experienced yesterday.

My kid wanted to stay late after school for a project, so I had to go pick her up. I decided to use the Tatra.

Now, when I drove the Tatra to Carlisle a couple weeks ago, the battery had gone flat. So flat it didn't want to take a charge initially. I swapped in my Imp 
battery (coincidentally the same group 53 battery I use for early Corvairs), charged the big battery overnight, and popped it into the other battery 
compartment.

A little Tatra design info is in order. See: http://fnader.com/images/Tatra/DCP_0018.JPG

That door at the forward end of the trunk is for one of the dual 6V batteries. A matching compartment exists on the other side... placement in no doubt 
designed to counter the weight distribution of the rear-mounted V8 above the rear swing axles... 

Most of us have converted the cars to use a large single 12V battery and use the other side for storage (tools, belts, etc) So I had a battery on both sides. 
The Imp battery, being much smaller, kind of rattled around in the battery box, but I figured it couldn't really go anywhere.  I was wrong.

Now this is AFTER the 2 hour drive to Carlilse and back and then sitting for two weeks in a garage (with 7 other cars).... I get no further than the end of my 
driveway (though I am now out in the street blocking traffic... luckily no traffic to speak of)  when the engine dies and won't restart. Electrical system is 
completely dead. And now I see smoke... coming from the front of the car.

I grab my extinguisher and race around the front and open the trunk. Smoke is pouring from around the edges of the battery door. I quickly remove the door 
and pull out the battery. It had bounced up out of the box and had lodged the positive terminal against the fender, where it was burning a hole through. I 
have NO idea when the battery jumped out... I doubt it was yesterday.... that means a gentle nudge could have started a fire in the garage any time in the 
last two weeks. 

Smoke is now EVERYWHERE.

I'm fairly certain that the battery had AT MOST another few seconds to go before it blew. (I have a friend with a glass eye from trying to jumpstart a new car). 
The positive terminal was glowing red and the insultation was melting off the wire. All of the juice from the battery AND the generator was feeding into that 
one point.

Keeping my eyes averted, I quickly grabbed my wrench and loosened the cables. Burnt the %&$* out of my thumb pulling the postive cable off. Got the 
battery out of the car and onto the side of the road... acid now bubbling up from the case of the battery around the terminal.  

I was able to quickly install the spare battery (without burning myself this time). The car started up just fine and a quick check with my multimeter showed the 
generator appeared uninjured.  Total damage was 1 trashed battery, a 3" circle of paint burnt off, and a blistered thumb.

Moral (similar to my VW Wesfalia story yesterday) is "don't take stuff for granted... do it right instead of quickly." Also that carrying an extinguisher and simple 
hand tools is a real good idea even if you never have to use them. If I hadn't had that wrnech with me, I think the battery would have leaked acid into the 
trunk (if not something worse).

Bill Elliott