I"m considering watching for a TIG welder and note that there are
different types of high frequency starting.

It looks like the lift to start method is on less expensive machines.
I assume that you tap the tungsten on the work and then lift to get it
started. Does that contaminate the tungsten?

Can lift to start machines use remote amperage foot pedal or thumb
controls?

What's the disadvantage of a lift start machine compared to whatever
the better machines have?

Is there high frequency at all on the scratch start machines?

On the better machines, I see that there's HF on start only and
continuous HF - I guess the latter is only on older machines, right?.
If you're down in the cellar or out in the garage is HF likely to
interfere with electronics say 50 ft away?


Ignoring interference, is there any disadvantage to a machine that has
continuous HF?

What's the purpose of a pulser?

TIA
RWL

On 2008-09-30, GeoLane at PTD dot NET GeoLane wrote:
I"m considering watching for a TIG welder and note that there are
different types of high frequency starting.

It looks like the lift to start method is on less expensive machines.
I assume that you tap the tungsten on the work and then lift to get it
started. Does that contaminate the tungsten?

Tip to start does not involve high frequency. It is called lift arc
and involves the power supply starting off with low current, to
increase as it senses that the tungsten is being lifted.

Can lift to start machines use remote amperage foot pedal or thumb
controls?

sure

What's the disadvantage of a lift start machine compared to whatever
the better machines have?

No idea. I like HF, which is what I have.

Is there high frequency at all on the scratch start machines?

No, it is the worst of all worlds, where you have to have super
dexterity to start the arc, without contaminating material with your
touch.

On the better machines, I see that there's HF on start only and
continuous HF - I guess the latter is only on older machines, right?.

Continuous HF is needed on sinewave AC machines due to arc
extinguishing itself during zero crossing.

If you're down in the cellar or out in the garage is HF likely to
interfere with electronics say 50 ft away?

Not too much.

Ignoring interference, is there any disadvantage to a machine that has
continuous HF?

No.

What's the purpose of a pulser?

To agitate the molten pool.
--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/

GeoLane at PTD dot NET wrote:
I"m considering watching for a TIG welder and note that there are
different types of high frequency starting.

It looks like the lift to start method is on less expensive machines.
I assume that you tap the tungsten on the work and then lift to get it
started. Does that contaminate the tungsten?

Yes.
Can lift to start machines use remote amperage foot pedal or thumb
controls?

If it doesn't COME with that attachment, don't assume you can get one
for an old machine, or that even the specs on the components and pin
connections will be available. (Miller and Lincoln have manuals back to
their earliest TIGs, but don't assume that is true for others.)
What's the disadvantage of a lift start machine compared to whatever
the better machines have?

Shield gas pre-flow. I usually set 5 seconds of pre-flow on mine. When
the HF turns on, then I know the area is purged of air.
Is there high frequency at all on the scratch start machines?

Most likely, not.
On the better machines, I see that there's HF on start only and
continuous HF - I guess the latter is only on older machines, right?.
If you're down in the cellar or out in the garage is HF likely to
interfere with electronics say 50 ft away?

No, continuous HF is for aluminum and other materials that tend to
contaminate the electrode, HF-start is for steels, mostly.

Ignoring interference, is there any disadvantage to a machine that has
continuous HF?

Yes, it may contaminate the electrode or the weld, or just affect the
weld appearance.

What's the purpose of a pulser?
Now you're getting into the deep stuff. It can be handy when welding
thin materials, or welding thin to thick. You definitely need to be in
the "expert" class before starting to use such features. I'm definitely
NOT there, yet.

Jon