[Gmecm] Welding vs. computers

[bcroe at juno.com]

I would not remove the battery for welding.  That is a 
precaution when working on/around wiring.  Bruce Roe

20 Nov 2006  "Doug Chase" <doug at chaserace.com> writes:
> It definitely makes sense to me that electronics could be subject to 
> damage
> if the proper precuations aren't taken.  Grounding to the chassis 
> while
> welding on the exhaust, for example, could have an O2 sensor as a 
> casualty.
> 
> It also makes sense that completely removing components will protect 
> them
> from being damaged by things I haven't thought of.
> 
> What does NOT make sense is to why disconnecting the battery, a 
> common
> precaution I've heard, would protect anything.  It seems to me that 
> it might
> be even better leaving it in.  At least that way you have a very 
> large
> capacitor to protect against voltage spikes on the +12 side of 
> things.
> Thoughts?
> 
> Doug Chase
> www.chaserace.com
> 425-269-5636
> 
> -----Original Message-----
> From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org] 
> On Behalf
> Of bcroe at juno.com
> Sent: Sunday, November 12, 2006 4:05 PM
> To: gmecm at diy-efi.org
> Subject: [Gmecm] Welding vs. computers
> 
> I second that.  Completely disconnect delicate electronics before 
> welding.
> A car isn't one mass of metal.  Many parts are isolated by 
> rubber,etc.  So
> things like ground straps and exhaust pipes may be taking big 
> currents,
> which aren't so predictable.  Not only the resistance is a factor, 
> but the
> arcing weld current will respond to inductance in the circuit.  If 
> the
> original ground system isn't in perfect condition, currents have 
> been known
> to find their way through things like shift cables.  
> 
> Do tie your welding ground to the piece of metal being welded, 
> reasonably
> close to the weld.  If there are 2 pieces, tie them electrically 
> together.  
> 
> Bruce Roe