Welding on a 1999 spartan chassis

All I could find in my manual was the Cummins engine manual says to disconnect both battery posts. No info about it in the Allison manual or anywhere else in the Spartan manual.

MrWizard wrote:
I have welded on several of my RVs with a wire feed welder Not Stick, with batteries connected
And I have had welding done at a shop

Facts
Without a proper ground the welder cannot even strike an arc,
The danger is not usually welding amps traveling the wrong path
Any danger to electronics, is Magnetic field induction,EMF, welding to close to a sensor or IC that is sensitive

When welding heavy materials, like truck frames, I prefer stick. But that might be because mostly need to do it with portable.
And it is true, you can't strike an arc without a good ground, the attempt is what can cause damage. This is why I, if the job is going to require weld, change positions, weld, repeat, and chance the groudnd loose contact, I tack the ground clamp first.
The little I know about EMF, is the reason I say ground close to work.

ON most of the frame I do not recommend welding. There is a reason for this. Sounds like you are welding on the rear end (That's one of the places where welding is acceptable)

I rather like the way SSS (Simpson and Son's Service) did the welding on my hitch.

On the workbench in the shop

Then they came out and BOLTED it to the frame rails (Existing bolt holes as the hitch was originally bolted there before it failed) Their rebulild is still rated at 5000 tow weight but easily 2000 hitch weight (The original was not that good and the Drop Hitch adapter torqued it right off the RV.. They over built when they put it back together)

I have had good luck majority of time welding on vehicle frames BUT there have been time it blew light bulbs. Do you play the lottery?

The safe way and not take the risk of damaging some electronic or electrical devise is to REMOVE the receiver and do any necessary fabrication and then replace the completed project. What is the time saved by not removing it worth?

I have welded on several of my RVs with a wire feed welder Not Stick, with batteries connected
And I have had welding done at a shop

Facts
Without a proper ground the welder cannot even strike an arc,
The danger is not usually welding amps traveling the wrong path
Any danger to electronics, is Magnetic field induction,EMF, welding to close to a sensor or IC that is sensitive

Suspect we are seeing a mix of "Best Practices" as well as "What I got away with".

Choose which path you want to follow-- it is your coach/your decision.

RLS7201 wrote:
I've stood in Tiffins' Red Bay weld shop and watched them weld on frames without them disconnecting any thing. Get your ground clamp close to the weld area and go for it.

Richard

I have laid under a truck in Gladstone Mo and welded a broken walking beam back together, and never disconnected anything. (walking beam is the part that mounts between axles, the spring mounts to it. Holds up that corner of truck) Told owner to dump load, go home and replace beam.
OTOH, a quick tack to hold a bracket on my old utility trailer burned out every lamp.

RLS7201 wrote:
I've stood in Tiffins' Red Bay weld shop and watched them weld on frames without them disconnecting any thing. Get your ground clamp close to the weld area and go for it.

Richard

Exactly, I doutb any manufacture disconnects anything before welding on the chassis. There is too much of a chance of forgetting to reconnect things as the build goes on.

I've stood in Tiffins' Red Bay weld shop and watched them weld on frames without them disconnecting any thing. Get your ground clamp close to the weld area and go for it.

Richard

Fire may be a bigger hazard than stray electrons. If you unplug things, make a list and a general location of the plugs for reconnecting. Take pictures, lots of pictures. Dielectric grease is you freind here. Remember, when you plug things back in, they may not come back like they should.
Good luck.