opinions on Lincoln Precision TIG?

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/Catalog/equipmentdatasheet.asp?p813), but the 275 is also nice (http://www.mylincolnelectric.com/Catalog/equipmentdatasheet.asp?pT08).
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?
Thank you for any replies, Al
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I like mine fine. It's not built for heavy duty TIG, but it does all the work a 70+ year old can handle. I sold all my heavy equipment. Bugs
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Use Google and look for comments by Ernie. He teaches welding at a community college. The Lincoln welders are great, and I think they include more advanced controls as standard than Miller. The water cooled torch becomes important at higher currents. The 185 will probably be as much as you need for stainless. Stainless does not conduct heat as well as regular steel so less current is needed. Aluminum is where the extra current is needed.
If I were you, I would also look at inverter welders. They are smaller and lighter. I forget which one Ernie says is the best buy. Most inverter welders do not provide AC, and are therefore not especially good for Aluminum. But one of them does ( not Miller or Lincoln ).
Dan
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On Ernie's recommendation I bought a Thermal Arc 185 TSW, which I'm guessing is the machine to which you're referring. AC, DC, pulsing, sequencing, very small and light, and of course, it's exceedingly purple. I like mine.
Peter
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On Sat, 16 Apr 2005 12:10:41 GMT, "Alan Raisanen"

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_store.cgi?page=pump.html&cart_idg38010_22723
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snip----

I have always used a hookup to our culinary water for my torch, and run the small amount of water involved to waste. It works fine and eliminates the need for a pump and cooling unit. May not be good for everyone, but it works for me.
Harold
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As long as you run a filter on the line. Otherwise you can get a buildup in the torchhead.
It is what I have been doing for 12 years.
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the
the
it
Good point, and I thank you for the tip. I didn't have a filter when I resided in Utah, but our water system here is filtered, so I'm likely in pretty good shape.
When I built the shop I installed a water hookup at the welding station, plus a discharge line that goes to our rain catch basin. Everything is concealed in the wall, so it's a clean setup. Interestingly, I've never assembled the system, but I'm in process right now---I have to weld some stainless pipe to steel pipe, plus attach some mounting brackets. I'm putting a couple antennas on the roof of the new house we're building, and they're being mounted to the reinforced trusses instead of surface mounting them. That will eliminate the need for guy wires and multiple holes in the roof. I don't want any leaks to deal with in the future.
The stainless portion of the 1-1/2" pipe will be above the roof, with the steel pipe in the attic space, where a little rust makes no difference. The pipe in the attic runs from the top to bottom chord of the trusses, which have been braced to prevent any movement. The antenna masts will be mounted by bolts, not nailed. I intend to TIG, with 308 filler for the dissimilar metal connection, and 70S 2 for the all steel connections. If you see any problems with my plan, I'd appreciate some guidance.
Harold
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Get some 309L for the dissimilar metals joints. It works much better for such things.
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choice at

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pump
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eliminates
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Thanks, Ernie. I'll check with the two suppliers in "the big city" on Tuesday for some 309L..
Harold
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wrote:

with
fair
saw
planning
in
steel
for
more
(1/8"
experience.
the
other
(5-185A
http://www.arc-zone.com/catalog/web_store.cgi?page=pump.html&cart_idg38010_22723
That is only useful if you have one to exchange, otherwise it's $238 for the new one. Seems like Ernie had a place to buy one new for less.
William....

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http://www.arc-zone.com/catalog/web_store.cgi?page=pump.html&cart_idg38010_22723
Water pump info
You need 50 psi water pressure to get the water through the head.
You can buy just the pump and build your own water cooler with a 5 gallon water bucket.
These guys sell the pumps direct
Depco Pump Company 2145 Calumet St Clearwater FL 33765 Phone: 727.446.1656 800.446.1656 Fax: 727.446.7867
Business Hours: -Monday thru Friday 7:30 AM to 5:30 PM ---Eastern Time
Tell them you are interested in the constant pressure gear pumps used for welding water coolers.
They have an Italian brand that works very well called Fluido-tec.
Procon replacement Fluido-tec PA301X-100PSI $86.36
Oberdorfer 1000R-39 $139
These pumps require a 1/3 HP 1750 RPM motor
Another source is Grainger
Product Category: Pumps & Plumbing > Pumps > Gear Pumps Description: Bronze Carbonator-Mount Rotary Gear Pump Head without Adjustable Relief Valve, 1/4 inch connectors
Your Price: $108.25 Grainger Item#: 2P381 Manufacturer: TEEL Mfg. Model#: CBN2 Catalog Page: 3270
www.Grainger.com
The pump model used by Tweco is: Procon #101C100F11B060 100 Gal per Hour @ 60 PSI
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Thanks for the information, gentlemen. I'm leaning towards the 275, I will go talk to my local supplier tomorrow and see what kind of prices they are quoting. Looking forward to learning a new technique!
Al
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