On Sat, 16 Apr 2005 12:10:41 GMT, "Alan Raisanen"
wrote:
Greetings all,
I have been toying with the idea of upgrading my welding capabilities with
one of the Licoln Precision TIG welders for a while. I currently do a fair
amount of stick welding and oxyacetylene welding, cutting and brazing. I saw
these machines being demonstrated at the last EAA Oshkosh show I attended
and was suitably impressed.
My needs are primarily hobby-based, not production. I'm not really planning
on earning a living with this thing. The kind of stuff I do have included in
the past:
- wood-fired hot water boiler for shop heating, fabricated out of 1/4" steel
plate
- homebuilt aircraft construction
- tractor restoration
- fabrication of components for high vacuum systems and plasma systems for
my research at the university
Materials of interest are aluminum alloys, stainless steel, and the
occasional copper components. Generally, fine control is likely to be more
important than brute force welding of heavy materials...I am thinking
aircraft welding, body work, stainless vacuum components with flanges (1/8"
wall or so), etc. I can always fall back to stick and O/A to join the big
stuff.
I know the basic concepts behind TIG processes, but have little experience.
The Precicion TIG 185 systems look like a nice compact unit
(http://www.mylincolnelectric.com/Cat...et.asp?p=12813),
but the 275 is also nice
(http://www.mylincolnelectric.com/Cat...eet.asp?p=5408).
I have 100 amps of 208 available in my shop. Maybe the 275 unit is too
beefy? At what point does a water-cooled torch become important versus the
air cooled torch? Is the "advanced control panel" (w/adjustable pulse
frequency, on time, background current controls, downslope timer, and other
stuff) likely to be useful, or wasted on a TIG neophyte? And what are the
typical upper limits of material that can be handled by such units (5-185A
DC for the 185 vs 2-340A DC for the 275), for the odd job where a
substantial aluminum or stainless weldment must be joined?
The 275 won't overload your 100-amp service. I think the 185 would
serve your needs well for far less $. You'd need the higher
current of the 275 for prolonged welding of heavy aluminum, but you
could certainly do up to 3/16" aluminum with the 185. You could
probably do 1/4" al though it might take a bit longer and/or require
multiple passes. If you plan to do a lot of work with 1/4" or
larger aluminum then you'll want the bigger machine. Otherwise, I
think the 185 would be quite sufficient. It'll do 1/4" stainless and
mild steel very nicely.
Note that the 185 has only a 15% dutycycle at full current. That's
based on a 10-minute cycle, so 8.5 minutes "rest" after 1.5 minutes of
arc time at full load. That could be a serious issue in a production
shop, but probably a non-issue for your use. 1.5 minutes is a lot of
continuous arc time for hobby work.
A water-cooled torch is not necessary, but they are very nice for
small work because they're physically small and easy to handle.
They're also nice in that you don't have to wait for them to cool
before changing tungstens -- and you'll do a lot of that at first with
TIG. When (not if) you dunk the tungsten you must stop, break off
the contaminated tip and regrind it.
They aren't expensive; the Weldcraft WP-25 might be a good choice at
a bit over $100. You don't need a full-blown water cooler, just a
pump and a bucket. You can get a refurbished ProCon coolant pump
for $118:
http://www.arc-zone.com/catalog/web_...=6738010_22723