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correct and correct.Quote:
Originally Posted by TODA AU
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.
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...
MIG will do a better job of burning through the crap that hides in the seams. So I use MIG for seam welding jobs.
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.Quote:
Originally Posted by Dy_
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).
A few things:Quote:
Originally Posted by Dy_
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.
I think TIG is more delicate than MIGQuote:
Originally Posted by joyride
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.
so.. in theory you shouldn't weld to the chassis? even its just a hanger?Quote:
Originally Posted by TODA AU
If its an metal connetion to chassis and its an electric welder then no. Oxy Acetylene no problems.Quote:
Originally Posted by ekdez
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...