What to do before welding.

[benji]

Finally going to get this rear bar on, it's only been a year...

There are two plates to be welded to the chassis, and im wondering what others have done in terms of ecus etc.

The guy who's doing it says he just dissconnects the battery, but rave says to disconnect all the ecus.

Not quite sure.

[Keithy P38]

Just disconnect both battery terminals and you'll be fine.

[justinc]

Step 1; remove drivers seat, step 2; remove BECM, step 3; drive to nearby town and store said BECM in airtight lightning proof container, in back shed, away from powerlines. Step 4; return to vehicle and carry out welding task. Reassembly is a reversal of removal...



JC

[RR P38]

Mmm, use bolts.

Keep the earth as close to the welding site as possible.

Pretty sure I would follow Keithys suggestion here and disconnect the ecu`s

[benji]

Thanks again guys.

Was thinking the same thing. Essesentially a closed dc circuit, but lr went overboard .

Shouldn't laugh about the power lines though, was talking to a guy once who had a merc that would stop in the same place every single time, turned out to be the electrical interference from the high tension wires stuffing with the electrics on the car.

[rc42]

Generally bolting is recommended rather than welding and there may be some legal issues too. Other information I've seen suggests that its only the structural parts of the chassis around the springs and steering that this applies too but I haven't seen any authoritative information for that.


http://www.infrastructure.gov.au/roa..._COP_sec_2.pdf



"2.2 WELDING
2.2.1 A novice must not carry out the construction or modification of a chassis.
Numerous effects such as twisting and loss of strength can be caused by incorrect
penetration, preparation, or timing of weld deposits. Inspection of all welds and
the requirement for rework will be at the discretion of the Examiners. Structural
chassis welding is recommended to be carried out with the chassis fixed in a jig.
An example of a chassis jig is shown in diagram 2 (a) on the next page."

[clubagreenie]

Step 1; remove drivers seat, step 2; remove BECM, step 3; drive to nearby town and store said BECM in airtight lightning proof container, in back shed, away from powerlines. Step 4; return to vehicle and carry out welding task. Reassembly is a reversal of removal...



JC

You forgot step 1a. Build alfoil hat

[goingbush]

just don't put the earth lead at the front of the car to weld on the back.

if you earth clamp as close as possible to the work you wont have any issues.

x2 alfoil hat always works for me

[DoubleChevron]

just don't put the earth lead at the front of the car to weld on the back.

if you earth clamp as close as possible to the work you wont have any issues.

x2 alfoil hat always works for me

Don't unplug stuff .... This one is the simplest thing ever. If your worried about blowing anything up, pull *BOTH* bettery terminals off the battery and join them together with something like a jumperlead. The entire car is now "one circuit" and joined to earth.

You owuld have to be incredibly unlucky to damage anything either way. The cars electronics are quite well protected from power spikes etc... eg: have you ever seen an exhaust place bother to use any sort of spike protection before welding up your exhaust ?

seeya,
Shane L.

[snowbound]

I have heard that if you have your headlights on it will absorb the excess current while welding because they draw a lot of power anyway? Makes sense but I personally wouldn't risk it!