Hot Max SPG spool gun

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Hi Newb here my name is Bob I've been thinking about buying an HotMax SPG spool gun for some light aluminum work nothing over 1/8 in. Is there anybody here currently using one ?If so can you tell me what you think of it  pros and cons .I'm starting at the spoolgun and working my way back eventually ending up with an  actual mig unit .Since the spoolgun is the part I'll have in my hands all the time I think it's the most important part. Sounds crazy, but to me if I cant get a good spoolgun at a reasonable price then the welder is irrelevant  as I don't have a lot to spend on the complete setup.I have an ac/dc welder already and thought I might be able to adapt it to the spoolgun .I'm a master electrician so I think I could come up with a power supply and such for the gun control .Anybody have any opinions? advise?Thanks Bob
Reply:One an AC/DC stick machine won't do mig. Stick is a Constant Current power source, to do mig you need a Constant Voltage power source. Then you still need all the drive controls, gas solenoid etc.... Can it be done, probably if you are an electrical engineer. You are talking about a major DIY build starting from zero just to save a few bucks and end up with an inferior welder.A few general notes on alum mig. To do 1/8" you will be maxing out a 180 amp mig both in wire speed and volts. Alum is a wonderful heat sink and it take a lot more power to do alum compared to steel. If you plan to spend any time welding 1/8", you'd better plan on jumping up to at least a 200 amp class mig if not a 250 amp class mig because of the low duty  cycle at max amps on 180 amp class machines. Alum mig with a spoolgun also has a number of draw backs. It really isn't right for anything less than 1/16" because it's a hot process. It's also an awkward way to weld if you have to make rapid direction changes since you have to weld at almost 2-3 time what you would with steel. Swinging that big bulky gun around isn't easy at fast speeds like if you want to weld around small tubes or pipes. Last mig alum does not give you that nice stack of dimes look many are looking for with alum welds. That's tig, not mig.Alum mig is good for production work where weld appearance is 2nd to speed. It's good on long straight joints with plenty of access for the gun. It's usually best on alum 1/8" and up unless you have a dedicated alum mig running pulse with an dedicated push/pull feed system.Tig is what give you that nice look. It's best for thinner alum, say 1/8" and less with average "hobby" machines". It allows you to move "slower" so you can maneuver around obstacles and get into tighter places since the torch is smaller. A new AC capable tig will also set you back almost 3 times the cost of a mig with spoolgun. Figure a budget of no less than $2500-2800 to get a decent 200 amp tig rig new fully set up.Knowing just what you want to do will determine whether mig is even the process you want to bother looking at..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:I think it wouldn't be to hard to adapt a spool gun to a buzz box. The leads are pretty much just plug and play, just have to set up gas (not to hard with a solenoid). The wire would be constantly "hot" so as soon as you touched the wire to the work it would arc.You would just need to set up the gas like mentioned and power to the gun feeder. Should be easy for an electrical engineer. If I had the welder and gun I would give it a shot.
Reply:Originally Posted by VPTI think it wouldn't be to hard to adapt a spool gun to a buzz box. The leads are pretty much just plug and play, just have to set up gas (not to hard with a solenoid). The wire would be constantly "hot" so as soon as you touched the wire to the work it would arc.You would just need to set up the gas like mentioned and power to the gun feeder. Should be easy for an electrical engineer. If I had the welder and gun I would give it a shot.
Reply:Get a suitcase 12VS feeder. It will run off of a CC source. Or, go the correct route and get a MIG welder designed for the process you are wanting to do and accomplish what you are wanting. No sense in trying to reinvent the wheel hereLast edited by BCTimberwolf; 07-27-2012 at 03:14 PM.
Reply:But a suitcase is not going to run aluminum very wellTiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:Originally Posted by soutthpawI guess you just run your mouth without reading the posts before it and give incorrect information on top of that..  DSW's post.One an AC/DC stick machine won't do mig. Stick is a Constant Current power source, to do mig you need a Constant Voltage power source.
Reply:I'm actually modifying my 12VS so I can run a spool gun off of it. The circuitry in the feeder is designed to compensate feed motor voltage to correct for voltage fluctuations when welding with CC. May not be the most consistent weld, but it will be one more tool in my arsenal if the need ever arrived to use it. Plus I can still use it in CV in place of a SGA-100 to use a spool gun with my Bobcat.On a side note, I have hooked up a stick welder to my Hobart 6969A MIG welder and it welded just fine if I kept a constant stickout. I was using the feed motor in the hobart and the amperage was coming from the stick welder. So the feed and amperage were constant but voltage was fluctuating. So I wouldn't say "it can't be done." It just may not be the most ideal way to approach it.
Reply:Hi Bob, it is your lucky day  I grabbed an spg off ebay to put on my quick-fix, it just showed up today and I am sorting out the control details.I took it apart and it is basically a can motor, speed 400 size.I applied 12 volts to it and observed the following:it took 18 seconds for the feeder wheel to turn 60 revolutions (unloaded).where the wheel would contact the wire is ~ 3/4 inch in diameter.The motor did not change in temperature noticeably.So if I figure correctly, the feeder would move 471 inches per minute (unloaded, so a little fudge needed) at 12 volts, which is close to normal for 0.023 steel wire.  My existing motor/controller is 24v, I will just pull out the existing motor wires and run them to the spool motor and leave the dial in the middle and see what happens.  The can motor is so inexpensive to replace I am not even going to worry about it.Also the wire colors are:red: motor +white: motor -yellow/green: switchThe plug comes apart easily, remove 2 strain relief screws and untwist the body.My original gun got wet and rusty, and replacements are about what I paid for the unit, so I chose the ebay spoolgun after repair didn't work, just for flux core for now but I will look at what is possible with it (and look for a deal on something in the 220v department someday). I secured the gun cable by grinding the end down into a cylinder that fit in the original century bracket.  Will worry about a tank later (24v solenoid), have stuff to fix now Also tips and shrouds seem interchangeable with the century.Last edited by daveid; 11-29-2012 at 10:23 PM.