can a mig welder be converted to a tig welder by changing to a tig torch
thohul
Thanks.
Andrew Holder
In article <5ldn63$r...@opal.southwind.net>, Dave Evans
<dev...@terraworld.net> writes
>In article <3379b085...@newshost.pcug.org.au>, tho...@pcug.org.au says...
>>
>>Thanks.
>
>SP-100,
>SP-130, and SP-140s that are design as a mig welder. A lot of my customers
>are tiging with them. They take a contact tip and drill out the hole
>so a tungsten will fit in it. Then they drill and tap a hole in the side of
>the contact tip for a set screw to hold the tungsten in.Place this
>in the mig torch, and remove the mig wire roll.Walla a tig/mig torch.
>remenber to Reverse the polarity of the torch leads, which is
>very easy on these Lincoln’s. And change your gas bottle.It makes a very
>good tig weld. I think it's one of the best kept secrets around.
>I hope this helps.
>If you would like more information on what makes a mig/tig machine just ask.
>Also if you can tell me the model No# code or ser# it would help.
>
>
>
Dave,
Thanks too from me. I have a SIP 130 MIG / gasless welder. For gasless
you swap the leads around. Does this mean that I could do the above with
it?
Please forgive this crass newbie question but how does a TIG actually
work? Does it have wire feeding through it or do you have like a brazing
rod? Also, what gas do they use?
Thanks again.
Andrew.
___________________________________________________
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** Embedded Microprocessor Solutions **
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Salisbury UK. Tel. 01725 513844 Fax. 01725 513845
e-mail And...@resmon.demon.co.uk (remove xxx)
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Dave Evans
It depends on your welder. A mig welder is a constant voltage power source.
Which means that it tries to keep the voltage constant no matter the
arc length. A tig welder is a constant current welder which tries to keep
the current the same and raise the voltage when the arc lenght gets longer.
Its hell trying to weld with the wrong welder. Some of the newer, home owner
special, mig welders are not very constant current, or constant voltage.
So they work just as well at tig as mig. If you try this remember to
change the polarity. The Work ground (-) should go to your tig torch, and the
lead to your mig torch (+) should go to ground. We sell a lot of Lincoln
Sheila Thomas
In article <iJzYjhAd...@resmon.demon.co.uk> And...@resmon.demon.co.ukxxx writes:
>Please forgive this crass newbie question but how does a TIG actually
>work? Does it have wire feeding through it or do you have like a brazing
>rod? Also, what gas do they use?
If you take a look at
http://www.twi.co.uk/bestprac/jobknol/jk6.html
you will see a brief description of the principles of this welding
process.
There are details of the equipment for carrying it out on
http://www.twi.co.uk/bestprac/jobknol/jk17.html
--
____________________________________________________________________________
home: mal...@granta.demon.co.uk http://www.granta.demon.co.uk
work: smth...@twi.co.uk http://www.twi.co.uk
Lap tops? Make mine small and feline!
____________________________________________________________________________
Andrew Holder
In article <863729...@granta.demon.co.uk>, Sheila Thomas
<mal...@granta.demon.co.uk> writes
>In article <iJzYjhAd...@resmon.demon.co.uk> And...@resmon.demon.co.ukxxx
>writes:
>
>>Please forgive this crass newbie question but how does a TIG actually
>>work? Does it have wire feeding through it or do you have like a brazing
>>rod? Also, what gas do they use?
>
>If you take a look at
>http://www.twi.co.uk/bestprac/jobknol/jk6.html
>you will see a brief description of the principles of this welding
>process.
>There are details of the equipment for carrying it out on
>http://www.twi.co.uk/bestprac/jobknol/jk17.html
Thank you very much Sheila.
Dave Evans
>Thanks too from me. I have a SIP 130 MIG / gases welder. For gasless
>you swap the leads around. Does this mean that I could do the above with
>it?
Andrew
To get yours to work, you will have a little more trouble. (You must have a
gas supply to tig. In tig the electrical arc is a plasma. It must have the
right gas molecules to ionize, and conduct the heat produced.)
If yours is one of those sold with out a gas solenoid.
I believe you have the same torch as the others with gas solenoids.
Somewhere near where the mig torch plugs in to the unit, there should be
a threaded plug for the gas. Also you need to remove that black shield over
your contact tip, and install a shield cup.
>Please forgive this crass newbie question but how does a TIG actually
>work? Does it have wire feeding through it or do you have like a brazing
>rod? Also, what gas do they use?
No wire feeding. You use a filler rod like in brazing.
I don’t call myself a welder. Just a welder repairman. I enjoy welding with
tig a lot, and I think most others do. To me is the finest welding art. But
for me to explain all the amazing ways to use this process, I might as well
try to explain what the answer is to the universe. (I know..... its 42. But
what
does that mean?)
If you get some Argon gas, to your torch with a tungsten mounted as I
talked about earlier, just make sure your ground clamp in on the wing-nut
lug with the positive mark. You will have to start the arc manually, by
scratching it on the plate, then pulling back. But not to far! Its takes some
getting use to. It will have a tendency to stick to the plate. When this
happens your welder will be shorted out. Its not nice to do that to a constant
voltage welder for very long.
Good Luck
Andrew Holder
In article <5lj61l$h...@opal.southwind.net>, Dave Evans
<dev...@terraworld.net> writes
> If you get some Argon gas, to your torch with a tungsten mounted as I
>talked about earlier, just make sure your ground clamp in on the wing-nut
> lug with the positive mark. You will have to start the arc manually, by
>scratching it on the plate, then pulling back. But not to far! Its takes some
>getting use to. It will have a tendency to stick to the plate. When this
>happens your welder will be shorted out. Its not nice to do that to a constant
>voltage welder for very long.
> Good Luck
>
Basically my unit is either gas or gasless, so I do already have a gas
supply to the torch and an external cylinder of gas.
The only difference for gasless is that you swap the polarity of the
leads around and don't turn the gas on !
So, I guess all I need to do is to modify the torch tip, swap the leads
so tht it's + to the clap and - to the torch, and turn the gas on.
Just a small point. I have a large cylinder of Argon/CO2 mix. I take it
this is not suitable for TIG with Aluminium?
I read that AC is better for aluminium because it cleans the oxidation
as it welds. I will obviously not have this luxury with DC so do I need
to do anything special to prepare the work ?
Thanks again for your help.
Dave Evans
>Basically my unit is either gas or gasless, so I do already have a gas
>supply to the torch and an external cylinder of gas.
>
>The only difference for gasless is that you swap the polarity of the
>leads around and don't turn the gas on !
>
>So, I guess all I need to do is to modify the torch tip, swap the leads
>so tht it's + to the clap and - to the torch, and turn the gas on.
Yes!
>
>Just a small point. I have a large cylinder of Argon/CO2 mix. I take it
>this is not suitable for TIG with Aluminium?
My copy of The Procedure handbook of Arc Welding recommends Helium for DC
electrode neg. welding of aluminum. The electrode used should be Thoriated
Tungsten.
>
>I read that AC is better for aluminum because it cleans the oxidation
>as it welds. I will obviously not have this luxury with DC so do I need
>to do anything special to prepare the work ?
Again, in looking it up. "A dull oxide film always covers the DCEN
bead at the edge and may cover the entire surface. This film is removed
easily by wire brushing.
>
George Reiswig
I'm confused about what polarity I'm supposed to use on some types of rod
when welding mild steel. I'm using a high-frequency DC arc welder.
Could somebody give me the recommended stinger polarities for the
following rods?
6013 -
7018 -
SuperMissile -
GP -
Stainless Steel "Blue Max" -
Thanks mucho, in advance.
GR
Dave Evans
Garrett,
Calling me Mr. Evans is like putting a elevator in a outhouse. They just
don’t
go together.
Lincoln makes great machines, so does Miller, Hobart , and some other
companies. What makes Lincoln stand out, in my mine, is the way they stand
behind their equipment. I could give you many examples, but unless you ask,
I won’t bore you with them.
My opinion of the SP-250 is good. If I could get one cheap, I would.
If I was to buy one, I wouldn’t. And that’s because of the computer, and touch
panel.
Turn one on, and it wants to know what size wire I’m using, then gas, then
what type steel, then what thickness! I don’t think its any of its business! I
want
to weld, the way I want to weld! I don’t need any damm machine telling me how
too.
Yes, I know there is a way to set the wire speed, and voltage manually, but I
find its like trying to program my VCR.
I wouldn’t try to tig with a SP-250, It would probably damage it.
Let me try to explain this. There are two main differences between a Tig
machine and a Mig machine. First. and most important. is Inductance.
A inductor stores energy like a battery, and opposes any change in Current.
So when you start an Tig arc by scratching the tungsten against the plate you
are directly shorting out your welding power supply! This will put enormous
current through the SCRs or diodes of your rectifier unit, unless you have
Inductance between the rectifier and the short, to oppose the change in
current. A Tig power source has this, your SP-250 does not.
The reason you can Tig with a SP-130, is it was made inexpensively as
possible, wile maintaining Lincoln quality and reliability.
So they made a little Mig welder with a lot of inductance in it. Therefore
you
can Tig with it.
I can imagine the people at Lincoln setting down discussing getting into
the Home owner market, Saying things like this. “Customers are asking us for a
inexpensively Mig welder. Can we build a inexpensive welder and still maintain
our reputation and quality”?
I think the answer is yes. But customers must understand that these
welders
are (Home Owner Specials) not a industrial welder.
An SP-250 is not a Home Owner Special and designed to be a very good Mig
power source with a flat slope or low inductance.
As for having to have a high frequency unit to Tig.
No, unless you must tig with AC. I believe you can tig most all metals with
DC.
But with out a high frequency unit you must scratch start it.
With DC, no high frequency unit is needed. Its a lot easier to start an Tig arc
with high frequency, because when you get the Tig torch close to the work, the
high freq. arc, jumps across the distance and starts the Tig arc. The Tungsten
never touches the plate. When using AC to Tig with out a high freq. unit your
arc will go out when the AC crossed from positive, to zero, to negative. A high
freq. unit will keep the arc from going out during the zero crossing.
Good Luck
Dave.
klebsar...@gmail.com
> Thanks.
ok. I am tired of seeing all you welders thinking you know about how electrical flow works. your welders not electrical engineers....I AM.
First, there is no such thing as "constant current" or "constant voltage". A mig welder CAN be converted to a Tig...ive done so.....
SO, LETS LEARN SOMETHING....
VOLTAGE AND CURRENT ARE INVERSELY PROPORTIONAL TO EACH OTHER! You cannot control current flow, and maintain a constant voltage! it doesnt work this way! the only control you have when dealing with a direct short (which is what welding is)is to adjust the voltage, which will inversely control current. You do this with the electronics on the primary side of your transformer. by lowering the voltage flow thru your primary, you can control the voltage flow thru your secondary (and therfore current flow thru your welded pieces). simple as that. So to answer your question, yes. you can convert a mig to a tig... you just have to stop listening to welders, and listen to people who understand how electricity works
Todd Rich
how usenet works.
You are replying to a 16 year old post.
Todd Rich
> On Wednesday, May 14, 1997 1:00:00 AM UTC-6, thohul wrote:
> > Thanks.
> ok. I am tired of seeing all you welders thinking you know about how electrica
l flow works. your welders not electrical engineers....I AM.
Ignoramus4149
Peter Fairbrother
Ernie Leimkuhler
is very difficult to hold a consistent heat because your heat will be
changing with your arc length.
jae...@gmail.com
Jesse Bear
'scuse me, I don't know where you went to engineering school, but BY DEFINITION, the voltage across a short circuit is ZERO, and you CAN'T change that. You can change the current limit through the short circuit and you can change the maximum open circuit voltage, but for love or money, you can't change short circuit voltage. That is ALWAYS zero.
Jim Wilkins
"Jesse Bear" <range...@gmail.com> wrote in message
news:fa4e25bc-f24b-4fec...@googlegroups.com...
http://www.lincolnelectric.com/en-us/support/process-and-theory/Pages/constant-current-vs-constant-coltage-output.aspx
-jsw
Jesse Bear
Now as to his statement that welding is a short circuit, I think there's plenty of room for discussion there.
Jim Wilkins
Not so. My old Sears AC stick welder has two voltage taps and a
mechanically variable inductive coupling between the primary and
secondary that controls the source impedance to set the "constant"
current.
http://en.wikipedia.org/wiki/Welding_power_supply
"This design typically allows the welder to select the output current
by variously moving a primary winding closer or farther from a
secondary winding, moving a magnetic shunt in and out of the core of
the transformer, using a series saturating reactor with a variable
saturating technique in series with the secondary current output, or
by simply permitting the welder to select the output voltage from a
set of taps on the transformer's secondary winding."
Electrical engineers used to be much cleverer with transformers before
they had small cheap transistors.
http://en.wikipedia.org/wiki/Hybrid_coil
http://en.wikipedia.org/wiki/Scott-T_transformer
http://en.wikipedia.org/wiki/Magnetic_amplifier
http://en.wikipedia.org/wiki/Constant-voltage_transformer#Constant-voltage_transformer
-jsw
Jesse Bear
When the electrode is stuck to the workpiece, that's a short circuit. Current may flow, but there will be zero voltage across that junction. When there is an arc, that's not a short circuit.
Ignoramus10918
Jesse Bear
> You have no clue whatsoever
Ignoramus10918
you understand anything about welding.
A welder is not a resistor. The job of a welder is to provide an
output of volts in relation to current, that matches the welding
process that is desired by the weldor.
For MIG welding, what is desired it to hold volts stable as the
current changes. For TIG and stick welding, it is desirable for the
welder to change its voltage as necessary, according to changes in
arc distance between torch and work, to try to maintin a stable output
current.
Can you connect a TIG torch to a MIG welder? Yes you can.
Will it work?
Not very well, because the welding output will change wildly, in an
undesirable fashion, as the distance between your torch and work
changes.
i
Bob F
Jim Wilkins
rod as 6.4 milliOhms from end to end at room temperature.
http://en.wikipedia.org/wiki/Four-terminal_sensing
That gives a 1V drop from the electrode holder to the short at the
work at 156A. E at the transformer secondary output will be a balance
between the magnetic field energy the secondary receives from the core
and the voltage drops in the cables, connections, clamps, workpiece
and rod.
You can pretend that R=0 in school, but not when you are building
high-current equipment like I did, such as test stands for 1000 Amp
locomotive power controls and Telco 48V backup battery chargers.
-jsw
Martin Eastburn
circuit. When a stick is stuck, the transformer hums - why - pumping
current out trying to clear the welded tip. There are active and
passive components in series between the transformer and the stick.
The large welding cables are not zero ohms in resistance. They have
resistance and get hot since high current is flowing. The transformer
core has 'copper' resistance. The inductive coil in series - to
fly-back and punch a high arc start is resistance. The wires within
the bus bars if any are resistive and so is any switch or plug/socket.
So when the stick is shorted, the maximum current allowed is the power
source and the sum of the resistances - remember to/from the stick
cables... So you might have 1/4 or 1/2 and ohm in leads and several
times that in the rest. Now say a nominal current of 100 amps is
flowing in the short. Then the voltage drop in these copper resistances
is the current times the resistance or I*R=E.
That voltage is the power source ability.
The transformer heats up and the primary draws excessive current popping
the breaker.
Martin - Degree in Physics and 30 years paid for electronics and black
magic.
Martin Eastburn
Your mind is focused on the melting tip.
There is a circuit of many resistance values and one near the tip is
even more like .1 or more ohms - steel isn't a good conductor. Neither
is the tig stick.
In many quality designs have very high purity copper, and silver contacts.
You have 1 current (unless there is a leakage path adding to it).
You have a main voltage source.
You have many little resistances between the voltage source to the short
and back to the voltage source (return line).
Think of I*(r1+r2+r3+r4+r5) = Total voltage of the source.
The voltage is dropped from the transformer winding, lead, switch,
motherboard, connectors, (and more connectors)and then the long lead
lines and the stick head connection (wire under a set screw) and the
jaws of the holder and the metal of the rod and finally to the tip.
Since you are globally speaking you miss the real facts within the hand
or stick holder you use while welding... and all of the other places.
This type of circuit is often modeled in software electronics to
understand a need or define not a need of a new hand unit.
Why are the 500 amp hand units larger and more expensive than the 50 amp
ones ? less resistance! - maybe heavy silver plating is used...
Martin
Martin
Jesse Bear
Jesse Bear
Jim Wilkins
Steel is only zero Ohms over zero distance.
Jesse Bear
Jesse Bear
I don't have a degree in physics but I do have 35 successful years designing electronics and keeping the smoke in the box.
Jim Wilkins
That's theoretically, and trivially, correct but it doesn't apply to
actual conditions on arc welders.
-jsw
Martin Eastburn
don't have zero voltage. A short isn't zero. Melted steel is has
resistance.
Martin
valle....@gmail.com
ezapa...@gmail.com
> Thanks.
Hi my name is Ermit and have Hobart Handler 140 mig welder it's about 3 yrs old with maybe 9 hrs. I was reading your posting so I am wondering if I can convert my mig to a tig. thanks for any in put you can give me. Thank you again E.Z.
Gunner Asch
Current..
The little Handler doesnt have the electronic sophisication to do
this.
Some welders ARE capable of all modes..but they tend to cost a couple
thousand dollars
"At the core of liberalism is the spoiled child,
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosophy of sniveling brats."
PJ O'Rourke
Phil Kangas
"Gunner Asch" <
> wrote in message
>
>>On Wednesday, May 14, 1997 at 3:00:00 AM UTC-4,
>>thohul wrote:
>>> Thanks.
>>
>>Hi my name is Ermit and have Hobart Handler 140
>>mig welder it's about 3 yrs old with maybe 9
>>hrs. I was reading your posting so I am
>>wondering if I can convert my mig to a tig.
>>thanks for any in put you can give me. Thank you
>>again E.Z.
>
> No..it cant. Its Constant Voltage..where tig
> and stick is Constant
> Current..
>
> The little Handler doesnt have the electronic
> sophisication to do
> this.
>
> Some welders ARE capable of all modes..but they
> tend to cost a couple
> thousand dollars
old!
Ermit is probably retired already.
This must be a new record for oldest post... ;>)}
pdk
Gunner Asch
Ignoramus31086
wheels to horse's hoofs and sticking a muffler up the horse's
"behind".
i
Gunner Asch
but not particularly well educated on the nuances of welding
technology.
Id rather have a bright kid ask than futz around and smoke his
welder/machine/electronics getting ahead of his knowlege base.
amdx
short is. When the electrode is stuck, we are probably down to micro
ohms, so maybe microvolts at the connection of the stuck stick. There is
more resistance around the rest of the circuit, what is the resistance
of the electrode?, the holder to electrode connection? then the cable?
the transformer windings, the ground connection. So, it depends on where
you measure the voltage. There is current flowing through a stuck stick,
limited by all the things I list above and a few more.
It would be interesting to measure the voltage at the transformer
output with a stuck stick. Does 40 Volt open circuit drop down to 5V,
9v when the electrode sticks?
FWIW, 50ft of #2 cable has 0.008 ohms of resistance. it drops 0.8V
at 100 amps.
Mikek
yachtw...@yahoo.co.uk
Gunner Asch
wrote:
>Hi David my mig welder is a sure welder 160 amps and it has a wire feed,what do I need to make into a tig welder Barrie
They work differently...one is CC and the other is CV...constant
current versus Constant voltage. Mig is constant voltage...TIG is
constant current.
Will you be able to strike an arc? Probably. Will you be able to weld
with it..maybe. Will you be able to weld properly with it? No.
---
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Gunner Asch
http://www.harborfreight.com/welding/tig-arc-welders/240-volt-inverter-arctig-welder-with-digital-readout-62486.html
et...@whidbey.com
constant voltage type and a tig welder uses a constant current type.
However, you can use a stick welder for tig welding. For that matter,
you can use an automobile alternator for tig welding. Just spend a
little time with your computer and your favorite search engine.
Eric