PowCon questions

Hi all,
I'm a welding novice. I've been using my Lincoln 135 Plus for a number of automotive projects at home, but have wanted a TIG welder. I did some TIG
welding a number of years ago and liked the precision and appearance of TIG in comparison to MIG.
Anyhow, I've been offered on very extended loan (meaning I can have it for free) an old PowCon 300ST that I've been told works. I have dinky shop and the small size of the PowCon makes it very attractive. I've searched the archives and come up with some info but am interested in a couple of things. I'm hoping that the folks on this NG can help a bit.
1) The unit does not come with a foot controller and I'd like one. I would prefer not to spend $280 for a pedal (one of the archived posters said that's what's wanted for a new one) and if I can score a relative cheapy on the used market, I'd be happier. Do I need to buy one specifically for the PowCon or are these "universal"? If they're not universal but not specific to the PowCon, what do I need to look for?
2) Someone in one of the posts I perused commented that inverter machines are not good for welding aluminum. True? False? Limitations?
3) The posts I've read seem to indicate that these are good machines, but expensive to repair. Any other comments?
4) I know that there are 300SS, 400SS, 300SM, 400SM, and 300ST available. Anyone know how the machines differ?
5) Any recommended TIG reference books? And yes, I am going to take a welding class or three...
Thanks muchly,
Peter
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Also... anyone have a manual?
Peter

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When I was in the Navy I used a 300ST but was unable to locate a Navy manual for it online. Here's the Navy publication number, perhaps you'll have better luck.S6240-B2-MMC-010
and title (I love how all book titles in the military are essentially written in reverse) WELDING MACHINE, PORTABLE, MODEL POWCON 300ST; DESCRIPTION, OPERATION, AND MAINTENANCE
As I remember, this was a nice machine to use and wouldn't mind having one of my own. It took one heck of a beating (on a submarine) and didn't have any problems. When the shore based maintenance guys came to weld (from nuclear welds to deckplate framework welding) they always used a 300ST as well, but that may have been because they didn't have a choice of another machine.
Shawn

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You can build one either from an older salvaged foot pedal like a heavy duty old Hobart, or you can use another kind of foot pedal like a Guitar volume pedal or sewing machine pedal.
What you need to know is what the resistance is for the potentiometer in the foot pedal. Then you will need some 18-5 cable and the correct connector for your machine. Total cost should be around $50.
These guys should be able to help you with the manual and any other info you need.
http://www.arcowelder.com /

I don't believe you have AC on that machine, so your options are to use DCEP with a huge tungsten, or run a spoolgun off of it like this one.
http://www.readywelder.com /

Yes and yes.

the main differences are going to be in features. Is the machine CC and CV.Does it have certain readouts of adjustment options. Also what power does it require. Many Powcons were 3-phase only.

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wrote:

Are there any disadvantages in getting a Readywelder spool gun to use with the Powcon and selling my Lincoln 135?

Is there an advantage in using three phase over single phase other than (I think) more power? I'm using a 5 HP RPC to power my mill. Is this suitable for a welder?
Thanks,
Peter
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Running the readywelder on thin sheetmetal with 0.024" wire requires a lower voltage. If your powcon has he ability to reduce it's open circuit voltage for rods like 6013, then it will work fine.
I do this on my Maxstar 200DX by increasing the "dig" control.
Otherwise I would keep the Lincoln 135 for thin stuff.

The powcons that ran on either single or 3 phase did it in a very simple way, by only using 2 out of 3 windings. So on 3 phase you get 300 amps output, but on single phase you only get 200 amps of output.
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wrote:

number of

machines
use
Thanks.
available.
So other than the "quantative" difference, is there any difference in the "quality" of the welds or the process?
Peter
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Not really. Inverters have inherently smooth arcs.
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Peter, I have a PowCon 300ST and a Powcon Plasma Plus. I have repaired about 10 PowCon machines over the past year and sold them on eBay (I have a 300ST for sale there now). I like the machines, they work great for me, a home shop welder.
Do I need to buy one specifically for the

Any foot pedal should work, you just may need to change the connector or pinout. I can get you the pinout diagram

I leave this one to the experts. I have not tried aluminum yet.

A new main board costs about $600, but a rebuilt board is $280. All are available from Arc Products.

The number is the max current (ie., 300 amps for a 300ST). The SS is SMAW, ST is SMAW and GTAW, the SM is SMAW and GMAW. The ST has a built-in gas selenoid ad capacitance start, the SM has a transformer to power a wire feeder. Both the ST and SM have special process relevant to tig (ST) or mig (SM) welding.

I'm looking for a book, too. I took a great welding course at the community college a few years ago, but it was mostly stick welding.
You can operators and service manuals for these machines from Arc Products for $25. I can answer most of your easy questions.
-Jason
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Powcons were very good machines. If not for Powcon, I doubt the majors offerings would not be as good as they are currently. Powcon bit the bullet and took the chance.
That said...
Foot pedals are generally not available. Hand controls can be obtained from CK Systematics and others. Old, used footpedals can be easily modified to work on the Powcon. A simple change of the pot and plug is all that is usually needed. Email me directly and I can give you details.
Most inverter machines are superior in the welding of aluminum.Their "constant energy" mode of operation is superior to the traditional constant voltage (CV) or constant current-drooper (CC). Also-as the inverter runs at a much higher frequency-often as high as 20000-50000Hz, the inverter reacts instantly to varying welding conditions.
Luckily enough, Powcon did not "proprietorize" a lot of their parts as is the custom with the majors. With the exception of transformers, frame and outer covers-many Powcon parts can be obtained from generic suppliers such as Newark Electronics, Allied Electronics, Graingers and many others.
ESAB and Miller both make good tig books available. I would recommend either or both. Read them-study them. Then practice.
Then take a course at a local vo-tech or community college, if you want.
There is no substitute for "time under the hood".
Hope this helps.
Good Luck
brad

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replying to Brad King, IndianaJohn wrote: I know this is a (very) old post, but I just got a free 300ST and want to modify a Miller pedal to fit. It already has a 14 pin Amphenol plug. If you could supply me with the pinout info for the PowCon and the pot resistance needed, I would very much appreciate it!
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replying to Brad King, IndianaJohn wrote: I know this is a (very) old post, but I just got a free 300ST and want to modify a Miller pedal to fit. It already has a 14 pin Amphenol plug. If you could supply me with the pinout info for the PowCon and the pot resistance needed, I would very much appreciate it!
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