arc welding

[hisoka]

Good luck....
Stick welding exhaust pipes would suck & propably end up looking like shit.
(Especially if done by a 1st timer)

Better off using a MIG or TIG...
If you're going to persist...
Get a really good welding helmet so you don't get flashed,
& practice heaps on stuff you don't need before you cost yourself more than you would if you pay someone else to do the job...
& if the parts are attached to the car...
Ge a surge protector or remove the ECU

correct and correct.

i was laughing, till i read this. no one even told him stick welding a exhaust was stupid.

as they said do a tafe course. if you know any boiler makers they can usally have it done in like 10 minutes, if its just a cannon being welded on.

not easy stuff. i did a radiator support once and holy shit that was a disaster.

[joyride]

i might hi-jack this thread a little... TIG or MIG when spot welding a chassis? seems like its a personal preference for most welders...

[82911]

MIG will do a better job of burning through the crap that hides in the seams. So I use MIG for seam welding jobs.

[JohnL]

john, what do you mean by spot welds?

Not 'real' spot welds (as you find in car body seams, made with a resistance welder), but each 'spot' being a very short arc 'run'. These 'runs' are so short that each one looks like a small circle, and each circle overlaps the previous circle, forming a chain of overlapping circles. When done well the overall weld can look very nice, but it's slow to do and can end up looking messy if you rush it or lack the knack.

The reason to do overlapping 'spots' is that between doing each 'spot' you can stop to allow the heat from the last 'spot' to conduct away from the weld site into the rest of the sheet / tube (where it dissipates).

Also i have noticed while practicing that the stick does tend to stick to the job...is there a way to prevent it?

A few things:

Aquire the knack of not letting it stick (which is a 'touch' thing that I'm still trying to properly master after 30 years).

Get the amperage right.

Make sure the steel is clean.

Grind / sand off the zinc plating where you are going to weld (this will also most probably result in a better weld with less porosity).

Use a stick / rod that tends to 'stick' less than other rods. I would suggest the 'Satincraft' rods (and similar from other manufacturers) as an easy(er) to use rod that gives good looking and ductile welds.

Some rods are harder to use / strike arc with than other rods, but give welds of a specific strength qualty. 'Easy to use' rods (such as 'Satincraft' and similar) tend to give softer welds that are less suitable for high structural loadings (you wouldn't build a boiler or a train undercarriage etc with them), but if you were forced to arc weld an exhaust would probably be the (type of) rod of choice.

Practice, practice....practice...............

For welding thin steel use a thin rod (I think 2.5mm is the smallest diamater).

My experience is that one of the hardest things when learning to arc weld is learning how to look through the arc and at the weld puddle (instead of looking at the arc). Once you get this it becomes a lot easier.

[Bludger]

i might hi-jack this thread a little... TIG or MIG when spot welding a chassis? seems like its a personal preference for most welders...

I think TIG is more delicate than MIG

[Dy_]

thanks for all the tips and comments people.
I've decided not to tackle my exhaust yet, but will be spending alot of time just practicing with random think and thin materials and see how i go.

[ekdez]

& if the parts are attached to the car...
Ge a surge protector or remove the ECU

so.. in theory you shouldn't weld to the chassis? even its just a hanger?

[DLO01]

so.. in theory you shouldn't weld to the chassis? even its just a hanger?

If its an metal connetion to chassis and its an electric welder then no. Oxy Acetylene no problems.

[JohnL]

My understanding is that it's OK to arc weld a chassis so long as the battery has been isolated (disconnect the earth terminal), and I've done it numerous times with no problems. This is no guarantee that the electronics will never ever get fried...