I need to weld some thin mild steel and find that my Mig is a bit
crude and vicious on mild steel this thin. I'm wondering if one of the
modern DC Tig inverter welders would be better for thin mild steel. Of
course a full AC/DC Tig would be nice for versatility but they never
come anywhere near a sensible price.
Any direct experience of the current crop of DC Tig inverter welding
kit welcomed.
Thanks
Charles
http://www.homeworkshop.org.uk
Tim - 22 Jul 2008 08:25 GMT
> I need to weld some thin mild steel and find that my Mig is a bit
> crude and vicious on mild steel this thin. I'm wondering if one of the
[quoted text clipped - 8 lines]
>
> Charles
Charles
No *direct* experience, but as no-one else has answered....
I've got what you might call a 'first generation' cheap & cheerful
inverter TIG set, it works, the HF (which is spark generated) seems to
me too powerful when working at low currents as it can tend to swamp the
welding current. Having said that, I've never really mastered TIG anyway..
It serves an excellent stick set, btw. Nowhere near as light & portable
as some of the current offerings.
Not TIG, just a basic stick set, I recently bought an R 140i from
http://www.newarc.co.uk/
which is a brilliant little set, with the emphasis on little. If you
could run to one of their TIG sets, I doubt that you would be disappointed.
im
moray - 22 Jul 2008 11:27 GMT
>I need to weld some thin mild steel and find that my Mig is a bit
> crude and vicious on mild steel this thin. I'm wondering if one of the
[quoted text clipped - 4 lines]
> Any direct experience of the current crop of DC Tig inverter welding
> kit welcomed.
I've got a Cebora DC set-up, but it's not exactly at the cheap end of the
scale, but certainly no where near the expensive end.
I picked mine up of ebay a couple years ago for a good price. I think I paid
about a 1/3 retail for a machine in as new condition.
It's mainly been used for repairing rusty body panels, but occasionally sees
use on stainless.
Personally I'd recommend paying more for HF start, as it makes starting
welds far easier. I have used the lift start option, and although it's
perfectly useable (might mainly be due to the cebora electronics which ramp
up the current after you lift off), HF is just so much easier.
Plus as Tim has said, it doubles up as a very nice stick welder (although
remember to swap the neg/pos leads around, otherwise it can make for some
interesting welding attempts!)
moray
Pip Luscher - 25 Jul 2008 20:18 GMT
>I need to weld some thin mild steel and find that my Mig is a bit
>crude and vicious on mild steel this thin. I'm wondering if one of the
[quoted text clipped - 4 lines]
>Any direct experience of the current crop of DC Tig inverter welding
>kit welcomed.
For really thin stuff, TIG with a pedal and/or pulse mode would give
the desired control. But they're expensive. Also, AFAIK TIG needs
argon or argon mixes, which are expensive.

Signature
-Pip
John - 28 Jul 2008 08:40 GMT
Do you have to weld this? Brazing may be a better alternative as it
doesn't melt the parent metal.
Have you considered gas welding?
When I needed to weld some thin steel, I found a gas set beat a MIG
welder. My technique was to use a thick filler rod as a thermal mass
to avoid making holes in the steel. Preheating the end of the rod to
almost meting point before applying it to the weld area helped as
well.
John
Charles Ping - 28 Jul 2008 12:13 GMT
> Do you have to weld this? Brazing may be a better alternative as it
> doesn't melt the parent metal.
[quoted text clipped - 6 lines]
>
> John
Thin steel with compound curves - and there's a lot of it to patch up
so silver soldering or brazing would be very expensive (even if I
could keep the heat distortion at bay).
Gas in my book has two big problems. The distortion is one and the
cost of the bottles is another. If I tot up what I've paid BOC in
rental over the past decade for just one argon bottle it'll be a lot
more than the cost of a TIG welder. The fact that I have MIG already
does mean that MIG and TIG can share gas and it becomes a sensible
option.
Charles
Tim Leech - 28 Jul 2008 12:51 GMT
>Thin steel with compound curves - and there's a lot of it to patch up
>so silver soldering or brazing would be very expensive (even if I
[quoted text clipped - 7 lines]
>
>Charles
Charles
Do you use straight Argon on your MIG?
I suppose it would be OK on thin material, I tried it on 4mm plate a
few years ago when I ran out of mixed gas, panic job on a Sunday, I
did struggle do get a decent result.
Tim
Mark Rand - 28 Jul 2008 22:23 GMT
>>Thin steel with compound curves - and there's a lot of it to patch up
>>so silver soldering or brazing would be very expensive (even if I
[quoted text clipped - 16 lines]
>
>Tim
I would have thought 4mm was a bit much even for mixed gas. pure argon would
probably be dire at that thickness.
Pub gas in bought bottles is far more economic than BOC's extortion for MIG
:-|
Mark Rand
RTFM
Tim Leech - 28 Jul 2008 22:45 GMT
>>Charles
>>
[quoted text clipped - 7 lines]
>I would have thought 4mm was a bit much even for mixed gas. pure argon would
>probably be dire at that thickness.
There are different mixtures for different thicknesses, BOC offer
Argon with 5% CO2 for thin stuff up to 4mm, 12% for 4 to 10mm & 20%
for 10mm & upwards, with a sniff of O2 for good measure.
Tim
moray - 29 Jul 2008 15:11 GMT
>>>Charles
>>>
[quoted text clipped - 14 lines]
>
> Tim
Conviently sold as Argoshield Light, Universal, and Heavy.
The O2 trace helps burn impurities out of MIG welds, but it means it's
useless for TIG welding, so you have to pay about twice as much for an
equivalent sized bottle of pure argon.