Harbor Freight TIG update
 

I got to play with the little machine last night. Got some nice welds with
aluminum and 3/32" thoriated tungsten electrode pos. Biggest problems I had
was trying to use too much current and too long of arc. Cerium electrodes
did not like to run pos..they vaporized :) Still haven't opened the box to
see if I can bypass the diodes on the final transformer for A/C .. looks
like it should work but there are sens wires connected to the output that
may cause some crazieness?
The 1/16" electrodes work fine for steel electrode neg. They just don't
clean enough for aluminum that way and cook with the other way.
Next stage is to play with thinner pieces and see if I can do what I bought
it for. Welding lightweight materials.
Things it is lacking,
Remote current control.
HF arc starter/stabilizer
A/C or adjustable square wave.
Adjustable post flow.
A good schematic so I can go in and change things :)

Glenn

In article , Glenn
wrote:

I got to play with the little machine last night. Got some nice welds with
aluminum and 3/32" thoriated tungsten electrode pos. Biggest problems I had
was trying to use too much current and too long of arc. Cerium electrodes
did not like to run pos..they vaporized :)

Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.


Still haven't opened the box to
see if I can bypass the diodes on the final transformer for A/C .. looks
like it should work but there are sens wires connected to the output that
may cause some crazieness?
The 1/16" electrodes work fine for steel electrode neg. They just don't
clean enough for aluminum that way and cook with the other way.
Next stage is to play with thinner pieces and see if I can do what I bought
it for. Welding lightweight materials.
Things it is lacking,
Remote current control.

You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.

HF arc starter/stabilizer
A/C or adjustable square wave.
Adjustable post flow.
A good schematic so I can go in and change things :)

Glenn

"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

I got to play with the little machine last night. Got some nice welds
with
aluminum and 3/32" thoriated tungsten electrode pos. Biggest problems I
had
was trying to use too much current and too long of arc. Cerium
electrodes
did not like to run pos..they vaporized :)
snip


HF arc starter/stabilizer
A/C or adjustable square wave.
Adjustable post flow.
A good schematic so I can go in and change things :)

Glenn


Any chance you could post a scan of the schematic somewhere or email it?

Tom

Thanks Ernie,
What would the advantage of Lanthanated be over Thoriated in the same size
for DCEP? I would have to order the Lanthanated as it is not stocked in
either of the 2 welding stores here in town.

As far as the foot pedal all I need to decide is if I want it to be a set
lower power with your foot off so you would push down to start the arc and
release to go to your set welding power or full power with no pressure (or a
set max) and decrease with pressure. The electrical part is no problem. It
is the practical part that has me hangin fire right now.

And Tom,
I can email a schematic or post it to the drop box. Gotta warn ya though it
isn't much of a schematic. The entire control board is a black box and the
inputs/outputs are not even named. I do plan to open it up and see if I can
get more info from the board and could send pics of that later too. I plan
to install a foot switch and see about wraping an HF tickler around the
output filter inductor. I want to look into bypassing the output diodes as
well but it may not be as simple as it seems. It appears to have some
feedback leads from the output that may be messed with if it is outputing
A/C. It appears they are sensing voltage rather than current though so it
may not matter. Then there is the matter of the big inductor that needs to
be gone for A/C and since that is the best place to hang an arc stabilizer
coil I will have to couple that up some other way.
Send me an e-mail and I will send you a scan.

Glenn

"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

SNIP
Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.

SNIP

Things it is lacking,
Remote current control.

You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.

Ernie Leimkuhler wrote:

In article , Glenn
wrote:


I got to play with the little machine last night. Got some nice welds with
aluminum and 3/32" thoriated tungsten electrode pos. Biggest problems I had
was trying to use too much current and too long of arc. Cerium electrodes
did not like to run pos..they vaporized :)


Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.



Still haven't opened the box to
see if I can bypass the diodes on the final transformer for A/C .. looks
like it should work but there are sens wires connected to the output that
may cause some crazieness?
The 1/16" electrodes work fine for steel electrode neg. They just don't
clean enough for aluminum that way and cook with the other way.
Next stage is to play with thinner pieces and see if I can do what I bought
it for. Welding lightweight materials.
Things it is lacking,
Remote current control.


You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.


HF arc starter/stabilizer
A/C or adjustable square wave.
Adjustable post flow.
A good schematic so I can go in and change things :)

Glenn


Just fished a Earnie Ball Volume pedal out of my son's dump box.
I gave it a good washing - I think excessive drink material was a dust collector :-)

So I scored it - It contains a high quality Pot - I haven't measured it yet.
Two phone plugs provides the three connections - or a new connector added to the
1/4" Al metal 'box'. Two U shaped turned such to have two flats outside.
It doesn't jump back when the foot is lifted - that is the why spring needed.

The pot - will be measured - just did - 100k ohm.


Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

In article , Glenn
wrote:

Thanks Ernie,
What would the advantage of Lanthanated be over Thoriated in the same size
for DCEP? I would have to order the Lanthanated as it is not stocked in
either of the 2 welding stores here in town.


I have run DCEP on aluminum for the last 7.5 years at school , showing
my students where aluminum welding started.
I find that Lanthanted tungstens work better than any other type for
DCEP.



As far as the foot pedal all I need to decide is if I want it to be a set
lower power with your foot off so you would push down to start the arc and
release to go to your set welding power or full power with no pressure (or a
set max) and decrease with pressure. The electrical part is no problem. It
is the practical part that has me hangin fire right now.


A foot pedal that decreases your power as you push would be the reverse
of every TIG I have used, but I suppose it may work.


And Tom,
I can email a schematic or post it to the drop box. Gotta warn ya though it
isn't much of a schematic. The entire control board is a black box and the
inputs/outputs are not even named. I do plan to open it up and see if I can
get more info from the board and could send pics of that later too. I plan
to install a foot switch and see about wraping an HF tickler around the
output filter inductor. I want to look into bypassing the output diodes as
well but it may not be as simple as it seems. It appears to have some
feedback leads from the output that may be messed with if it is outputing
A/C. It appears they are sensing voltage rather than current though so it
may not matter. Then there is the matter of the big inductor that needs to
be gone for A/C and since that is the best place to hang an arc stabilizer
coil I will have to couple that up some other way.
Send me an e-mail and I will send you a scan.

Glenn

"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

SNIP
Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.

SNIP

Things it is lacking,
Remote current control.

You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.

In article , Martin H.
Eastburn wrote:

Ernie Leimkuhler wrote:

In article , Glenn
wrote:


I got to play with the little machine last night. Got some nice welds with
aluminum and 3/32" thoriated tungsten electrode pos. Biggest problems I
had
was trying to use too much current and too long of arc. Cerium electrodes
did not like to run pos..they vaporized :)


Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.



Still haven't opened the box to
see if I can bypass the diodes on the final transformer for A/C .. looks
like it should work but there are sens wires connected to the output that
may cause some crazieness?
The 1/16" electrodes work fine for steel electrode neg. They just don't
clean enough for aluminum that way and cook with the other way.
Next stage is to play with thinner pieces and see if I can do what I bought
it for. Welding lightweight materials.
Things it is lacking,
Remote current control.


You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.


HF arc starter/stabilizer
A/C or adjustable square wave.
Adjustable post flow.
A good schematic so I can go in and change things :)

Glenn


Just fished a Earnie Ball Volume pedal out of my son's dump box.
I gave it a good washing - I think excessive drink material was a dust
collector :-)

So I scored it - It contains a high quality Pot - I haven't measured it yet.
Two phone plugs provides the three connections - or a new connector added to
the
1/4" Al metal 'box'. Two U shaped turned such to have two flats outside.
It doesn't jump back when the foot is lifted - that is the why spring needed.

The pot - will be measured - just did - 100k ohm.


Martin


CK Worldwide has a chart on their website that shows all the standard
ohm ratings for most TIG machine remotes.

Ernie Leimkuhler wrote:

In article , Martin H.
Eastburn wrote:


Ernie Leimkuhler wrote:


In article , Glenn
wrote:



I got to play with the little machine last night. Got some nice welds with
aluminum and 3/32" thoriated tungsten electrode pos. Biggest problems I
had
was trying to use too much current and too long of arc. Cerium electrodes
did not like to run pos..they vaporized :)


Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.




Still haven't opened the box to
see if I can bypass the diodes on the final transformer for A/C .. looks
like it should work but there are sens wires connected to the output that
may cause some crazieness?
The 1/16" electrodes work fine for steel electrode neg. They just don't
clean enough for aluminum that way and cook with the other way.
Next stage is to play with thinner pieces and see if I can do what I bought
it for. Welding lightweight materials.
Things it is lacking,
Remote current control.


You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.



HF arc starter/stabilizer
A/C or adjustable square wave.
Adjustable post flow.
A good schematic so I can go in and change things :)

Glenn



Just fished a Earnie Ball Volume pedal out of my son's dump box.
I gave it a good washing - I think excessive drink material was a dust
collector :-)

So I scored it - It contains a high quality Pot - I haven't measured it yet.
Two phone plugs provides the three connections - or a new connector added to
the
1/4" Al metal 'box'. Two U shaped turned such to have two flats outside.
It doesn't jump back when the foot is lifted - that is the why spring needed.

The pot - will be measured - just did - 100k ohm.


Martin



CK Worldwide has a chart on their website that shows all the standard
ohm ratings for most TIG machine remotes.
Found it in the amperage control data pdf.

I have a foot pedal and a hand control for my Miller SD180 - but I'm looking for additional welders
in the near future. :-) Nice doc.


Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

Works for me :) I will order a box of the lanthanated Monday.
So, if I understand this footpedal concept, I would mash the pedal to start
the arc and slowly release as things heat up such that with my foot off the
pedal it is running at the current I set for the normal running? Or do I
need to set both high and low limits? I just can't see using it as the
control for the current all the time as being very stable. As you
re-position your body your foot moves around and your current goes wonky.
I really appreciate your taking the time to gude me a bit here. There are
no welding schools here or I would be there now :) The welding shops mostly
tell me it is impossible to weld aluminum with DC :)
After doing a bit of reading on the web I am wondering if this machine might
be of the "Lift arc" type rather than a scratch start? I don't think I
would know the difference really.

Thanks for the info!
Glenn
"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

Thanks Ernie,
What would the advantage of Lanthanated be over Thoriated in the same
size
for DCEP? I would have to order the Lanthanated as it is not stocked in
either of the 2 welding stores here in town.


I have run DCEP on aluminum for the last 7.5 years at school , showing
my students where aluminum welding started.
I find that Lanthanted tungstens work better than any other type for
DCEP.



As far as the foot pedal all I need to decide is if I want it to be a set
lower power with your foot off so you would push down to start the arc
and
release to go to your set welding power or full power with no pressure
(or a
set max) and decrease with pressure. The electrical part is no problem.
It
is the practical part that has me hangin fire right now.


A foot pedal that decreases your power as you push would be the reverse
of every TIG I have used, but I suppose it may work.


And Tom,
I can email a schematic or post it to the drop box. Gotta warn ya though
it
isn't much of a schematic. The entire control board is a black box and
the
inputs/outputs are not even named. I do plan to open it up and see if I
can
get more info from the board and could send pics of that later too. I
plan
to install a foot switch and see about wraping an HF tickler around the
output filter inductor. I want to look into bypassing the output diodes
as
well but it may not be as simple as it seems. It appears to have some
feedback leads from the output that may be messed with if it is outputing
A/C. It appears they are sensing voltage rather than current though so
it
may not matter. Then there is the matter of the big inductor that needs
to
be gone for A/C and since that is the best place to hang an arc
stabilizer
coil I will have to couple that up some other way.
Send me an e-mail and I will send you a scan.

Glenn

"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

SNIP
Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.

SNIP

Things it is lacking,
Remote current control.

You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.

A single stero plug would give the three connections needed and give you
disconnect for the internal pot. A couple of screws to set min max ranges
on the foot pedal and you should be there. Seems like it would be more
convienient to have the min max settings on the welder though.

Glenn
"Martin H. Eastburn" wrote in message
...
Ernie Leimkuhler wrote:

In article , Glenn
wrote:
SNIP
Just fished a Earnie Ball Volume pedal out of my son's dump box.
I gave it a good washing - I think excessive drink material was a dust
collector :-)

So I scored it - It contains a high quality Pot - I haven't measured it
yet.
Two phone plugs provides the three connections - or a new connector added
to the
1/4" Al metal 'box'. Two U shaped turned such to have two flats outside.
It doesn't jump back when the foot is lifted - that is the why spring
needed.

The pot - will be measured - just did - 100k ohm.


Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

In article , Glenn
wrote:

Works for me :) I will order a box of the lanthanated Monday.
So, if I understand this footpedal concept, I would mash the pedal to start
the arc and slowly release as things heat up such that with my foot off the
pedal it is running at the current I set for the normal running? Or do I
need to set both high and low limits? I just can't see using it as the
control for the current all the time as being very stable. As you
re-position your body your foot moves around and your current goes wonky.

The most common way to run a TIG in a shop is with a foot pedal.
In a normal TIG machine, the first bit of movement of the pedal
triggers the contactor, which deliveres welding current to the
workpiece, turns on the gas and initiates the high frequency start.
As you push down your amperage increases.
So you can start off low, and ramp up until your metal melts.

With a little practice it is quite easy to hold a very constant current
level with your foot.

The way I run a TIG when weldingh stainless steel on location is to use
the Sequencer built into my inverter machine.

I tap a button on the torch handle, and it initiates a sequence that
starts with a preflow gas purge of 1/2 second, then initiates the arc
with high freq at 5 amps, ramps up over 1 second to whatever my main
amperage is set to, and then starts pulsing per my settings.
A second tap of the button triggers the downslope over 3 seconds to 2
amps, shuts off te arc and delivers 20 seconds of post flow gas.

Now whenI owned a much simpler Maxstar 140, I just set the machine to
the amperage needed for that material, opened the gas valve in the
handle, and scratch started the arc on the metal.
I would weld along the joint until I reached the end.
I would then whip teh torch away from the weld to break the arc, return
the torch to the previous position just as fast, wait til the tungsten
had cooled, and turn off the gas.

If you don't have a foot pedal, then you need to have a pretty accurate
idea of what amperage you need for what thickness of metal.

The basic rules:
1 amp per 0.001" of thickness for steel and aluminum, flat butt weld,
full penetration, single pass.

Add 1/3 for inside corners.
Subtract 1/3 for outside corners.

Subtract 1/3 for stainless steel and titanium
Subtract 1/2 for bronze.
Multiply it by 2 for copper.

So an inside fillet weld on 1/16" Stainless steel. would be...
1/16" = 0.0625" = 63 amps - 1/3 for SS = 42 amps, + 1/3 for inside
fillet = 63 amps.

Oh and never use a filler rod thicker than your base metal if you can
avoid it.



I really appreciate your taking the time to gude me a bit here. There are
no welding schools here or I would be there now :) The welding shops mostly
tell me it is impossible to weld aluminum with DC :)
After doing a bit of reading on the web I am wondering if this machine might
be of the "Lift arc" type rather than a scratch start? I don't think I
would know the difference really.


Do a google-groups search on my name in the archives for
sci.engr.joining.welding and you will find all my rantings and
ravings about TIG.



Thanks for the info!
Glenn
"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

Thanks Ernie,
What would the advantage of Lanthanated be over Thoriated in the same
size
for DCEP? I would have to order the Lanthanated as it is not stocked in
either of the 2 welding stores here in town.


I have run DCEP on aluminum for the last 7.5 years at school , showing
my students where aluminum welding started.
I find that Lanthanted tungstens work better than any other type for
DCEP.



As far as the foot pedal all I need to decide is if I want it to be a set
lower power with your foot off so you would push down to start the arc
and
release to go to your set welding power or full power with no pressure
(or a
set max) and decrease with pressure. The electrical part is no problem.
It
is the practical part that has me hangin fire right now.


A foot pedal that decreases your power as you push would be the reverse
of every TIG I have used, but I suppose it may work.


And Tom,
I can email a schematic or post it to the drop box. Gotta warn ya though
it
isn't much of a schematic. The entire control board is a black box and
the
inputs/outputs are not even named. I do plan to open it up and see if I
can
get more info from the board and could send pics of that later too. I
plan
to install a foot switch and see about wraping an HF tickler around the
output filter inductor. I want to look into bypassing the output diodes
as
well but it may not be as simple as it seems. It appears to have some
feedback leads from the output that may be messed with if it is outputing
A/C. It appears they are sensing voltage rather than current though so
it
may not matter. Then there is the matter of the big inductor that needs
to
be gone for A/C and since that is the best place to hang an arc
stabilizer
coil I will have to couple that up some other way.
Send me an e-mail and I will send you a scan.

Glenn

"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

SNIP
Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.

SNIP

Things it is lacking,
Remote current control.

You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.

In article , Martin H.
Eastburn wrote:

Ernie Leimkuhler wrote:

In article , Martin H.
Eastburn wrote:


Ernie Leimkuhler wrote:



CK Worldwide has a chart on their website that shows all the standard
ohm ratings for most TIG machine remotes.
Found it in the amperage control data pdf.

I have a foot pedal and a hand control for my Miller SD180 - but I'm looking for additional welders
in the near future. :-) Nice doc.


And as far as I can tell CK is the only company to have ever published
that list.

Damn, I gotta save this post

If you don't have a foot pedal, then you need to have a pretty accurate
idea of what amperage you need for what thickness of metal.

The basic rules:
1 amp per 0.001" of thickness for steel and aluminum, flat butt weld,
full penetration, single pass.

Add 1/3 for inside corners.
Subtract 1/3 for outside corners.

Subtract 1/3 for stainless steel and titanium
Subtract 1/2 for bronze.
Multiply it by 2 for copper.

So an inside fillet weld on 1/16" Stainless steel. would be...
1/16" = 0.0625" = 63 amps - 1/3 for SS = 42 amps, + 1/3 for inside
fillet = 63 amps.

Oh and never use a filler rod thicker than your base metal if you can
avoid it.




I really appreciate your taking the time to gude me a bit here. There are
no welding schools here or I would be there now :) The welding shops mostly
tell me it is impossible to weld aluminum with DC :)
After doing a bit of reading on the web I am wondering if this machine might
be of the "Lift arc" type rather than a scratch start? I don't think I
would know the difference really.



Do a google-groups search on my name in the archives for
sci.engr.joining.welding and you will find all my rantings and
ravings about TIG.




Thanks for the info!
Glenn
"Ernie Leimkuhler" wrote in message
.. .

In article , Glenn
wrote:


Thanks Ernie,
What would the advantage of Lanthanated be over Thoriated in the same
size
for DCEP? I would have to order the Lanthanated as it is not stocked in
either of the 2 welding stores here in town.


I have run DCEP on aluminum for the last 7.5 years at school , showing
my students where aluminum welding started.
I find that Lanthanted tungstens work better than any other type for
DCEP.




As far as the foot pedal all I need to decide is if I want it to be a set
lower power with your foot off so you would push down to start the arc
and
release to go to your set welding power or full power with no pressure
(or a
set max) and decrease with pressure. The electrical part is no problem.
It
is the practical part that has me hangin fire right now.


A foot pedal that decreases your power as you push would be the reverse
of every TIG I have used, but I suppose it may work.



And Tom,
I can email a schematic or post it to the drop box. Gotta warn ya though
it
isn't much of a schematic. The entire control board is a black box and
the
inputs/outputs are not even named. I do plan to open it up and see if I
can
get more info from the board and could send pics of that later too. I
plan
to install a foot switch and see about wraping an HF tickler around the
output filter inductor. I want to look into bypassing the output diodes
as
well but it may not be as simple as it seems. It appears to have some
feedback leads from the output that may be messed with if it is outputing
A/C. It appears they are sensing voltage rather than current though so
it
may not matter. Then there is the matter of the big inductor that needs
to
be gone for A/C and since that is the best place to hang an arc
stabilizer
coil I will have to couple that up some other way.
Send me an e-mail and I will send you a scan.

Glenn

"Ernie Leimkuhler" wrote in message
.. .

In article , Glenn
wrote:


SNIP

Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.


SNIP

Things it is lacking,
Remote current control.

You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.

Thanks Ernie,
There is a wealth of info there and I intend to spend a lot of time
reviewing it.
An intersting note... People are advertising this exact welder on Ebay for
up to $699.00! Most of them were in the $400 range but man are there some
sharks in those waters LOL
Glenn
"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

Works for me :) I will order a box of the lanthanated Monday.
So, if I understand this footpedal concept, I would mash the pedal to
start
the arc and slowly release as things heat up such that with my foot off
the
pedal it is running at the current I set for the normal running? Or do I
need to set both high and low limits? I just can't see using it as the
control for the current all the time as being very stable. As you
re-position your body your foot moves around and your current goes wonky.

The most common way to run a TIG in a shop is with a foot pedal.
In a normal TIG machine, the first bit of movement of the pedal
triggers the contactor, which deliveres welding current to the
workpiece, turns on the gas and initiates the high frequency start.
As you push down your amperage increases.
So you can start off low, and ramp up until your metal melts.

With a little practice it is quite easy to hold a very constant current
level with your foot.

The way I run a TIG when weldingh stainless steel on location is to use
the Sequencer built into my inverter machine.

I tap a button on the torch handle, and it initiates a sequence that
starts with a preflow gas purge of 1/2 second, then initiates the arc
with high freq at 5 amps, ramps up over 1 second to whatever my main
amperage is set to, and then starts pulsing per my settings.
A second tap of the button triggers the downslope over 3 seconds to 2
amps, shuts off te arc and delivers 20 seconds of post flow gas.

Now whenI owned a much simpler Maxstar 140, I just set the machine to
the amperage needed for that material, opened the gas valve in the
handle, and scratch started the arc on the metal.
I would weld along the joint until I reached the end.
I would then whip teh torch away from the weld to break the arc, return
the torch to the previous position just as fast, wait til the tungsten
had cooled, and turn off the gas.

If you don't have a foot pedal, then you need to have a pretty accurate
idea of what amperage you need for what thickness of metal.

The basic rules:
1 amp per 0.001" of thickness for steel and aluminum, flat butt weld,
full penetration, single pass.

Add 1/3 for inside corners.
Subtract 1/3 for outside corners.

Subtract 1/3 for stainless steel and titanium
Subtract 1/2 for bronze.
Multiply it by 2 for copper.

So an inside fillet weld on 1/16" Stainless steel. would be...
1/16" = 0.0625" = 63 amps - 1/3 for SS = 42 amps, + 1/3 for inside
fillet = 63 amps.

Oh and never use a filler rod thicker than your base metal if you can
avoid it.



I really appreciate your taking the time to gude me a bit here. There
are
no welding schools here or I would be there now :) The welding shops
mostly
tell me it is impossible to weld aluminum with DC :)
After doing a bit of reading on the web I am wondering if this machine
might
be of the "Lift arc" type rather than a scratch start? I don't think I
would know the difference really.


Do a google-groups search on my name in the archives for
sci.engr.joining.welding and you will find all my rantings and
ravings about TIG.



Thanks for the info!
Glenn
"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

Thanks Ernie,
What would the advantage of Lanthanated be over Thoriated in the same
size
for DCEP? I would have to order the Lanthanated as it is not stocked
in
either of the 2 welding stores here in town.


I have run DCEP on aluminum for the last 7.5 years at school , showing
my students where aluminum welding started.
I find that Lanthanted tungstens work better than any other type for
DCEP.



As far as the foot pedal all I need to decide is if I want it to be a
set
lower power with your foot off so you would push down to start the arc
and
release to go to your set welding power or full power with no pressure
(or a
set max) and decrease with pressure. The electrical part is no
problem.
It
is the practical part that has me hangin fire right now.


A foot pedal that decreases your power as you push would be the reverse
of every TIG I have used, but I suppose it may work.


And Tom,
I can email a schematic or post it to the drop box. Gotta warn ya
though
it
isn't much of a schematic. The entire control board is a black box
and
the
inputs/outputs are not even named. I do plan to open it up and see if
I
can
get more info from the board and could send pics of that later too. I
plan
to install a foot switch and see about wraping an HF tickler around
the
output filter inductor. I want to look into bypassing the output
diodes
as
well but it may not be as simple as it seems. It appears to have some
feedback leads from the output that may be messed with if it is
outputing
A/C. It appears they are sensing voltage rather than current though
so
it
may not matter. Then there is the matter of the big inductor that
needs
to
be gone for A/C and since that is the best place to hang an arc
stabilizer
coil I will have to couple that up some other way.
Send me an e-mail and I will send you a scan.

Glenn

"Ernie Leimkuhler" wrote in message
...
In article , Glenn
wrote:

SNIP
Zirconium electrodes also hate DC so don't bother trying them.
I would recommend using 1.5% Lanthanated for everything.

SNIP

Things it is lacking,
Remote current control.

You could go with a mechanical system .
A foot pedal with a brake bicycle brake cable attached that spins
the
amperage knob on the machine.

If you want to make a electric foot pedal try a $20 guitar volume
control foot pedal.
Just add a return spring.

On Sat, 19 Feb 2005 12:00:39 GMT, Ernie Leimkuhler
wrote:

In article , Martin H.
Eastburn wrote:

Ernie Leimkuhler wrote:

In article , Martin H.
Eastburn wrote:


Ernie Leimkuhler wrote:



CK Worldwide has a chart on their website that shows all the standard
ohm ratings for most TIG machine remotes.
Found it in the amperage control data pdf.

I have a foot pedal and a hand control for my Miller SD180 - but I'm looking for additional welders
in the near future. :-) Nice doc.


And as far as I can tell CK is the only company to have ever published
that list.

https://rs153.securehostserver.com/~...otcontrols.htm

conspicuously missing is Lincoln

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)

Ernie did say the CK worldwide web site. If I recall correctly Lincoln
is 10 kohm.

Dan
Gunner wrote:


CK Worldwide has a chart on their website that shows all the
standard
ohm ratings for most TIG machine remotes.
Found it in the amperage control data pdf.

I have a foot pedal and a hand control for my Miller SD180 - but
I'm looking for additional welders
in the near future. :-) Nice doc.


And as far as I can tell CK is the only company to have ever
published
that list.


https://rs153.securehostserver.com/~...otcontrols.htm

conspicuously missing is Lincoln

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)

The PDF file is here

http://www.ckworldwide.com/f190_1.pdf

Page 2 has the chart.




In article .com,
wrote:

Ernie did say the CK worldwide web site. If I recall correctly Lincoln
is 10 kohm.

Dan
Gunner wrote:


CK Worldwide has a chart on their website that shows all the
standard
ohm ratings for most TIG machine remotes.
Found it in the amperage control data pdf.

I have a foot pedal and a hand control for my Miller SD180 - but
I'm looking for additional welders
in the near future. :-) Nice doc.


And as far as I can tell CK is the only company to have ever
published
that list.



https://rs153.securehostserver.com/~...footcontrols.h
tm

conspicuously missing is Lincoln

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)