Post By MechWerks
LINDE HELIARC 250 HF TIG and Stick Welder
Hello, I'm new to welding and currently enrolled in a basic fabrication course. I have an opportunity to purchase a well preserved LINDE HELIARC 250 HF. It is in great condition, comes with gas cylinder and regulator, water cooling tank, pump and foot controller. It is single phase 220-240 V and has a water cooled tig torch. What should I pay for this, or should I look for something else that allows me to work on aluminum. Also, are there any advantages to the older Linde machine compared to modern tig units? Thanks in advance for your help and comments.
I am assuming the HF in the name means High Frequency.... if so, this machine is perfect for aluminum.
If it's the machine I think it is, I ran one at the museum for several years. Cut my TIG teeth on it to be more precise. Fantastic but very basic rugged industrial duty machine. No square wave or such, just a plain old HF AC/DC unit. It does have a rev polarity switch, but that's about it. Only thing to be wary of is keeping that water cooled torch and accoutrements out of freezing temps. We lost a cooler core that way (water froze and blew out the little radiator). I ran it pretty hard and it never let me down, otherwise.
The more common Linde TIG out there is the UC-305...tons of them out there. If this one does have AC, then you're good to go for Al. Call Larry @ WeldmartOnline (Houston, TX area) - he's an ex-Linde guy (~20+ years with them) and knows all the machines, which ones are good, what to do to keep them going, and he can get most any parts for them too. Steve
You may want to run the serial number through a welding supply store to find the age of the machine..might be pretty old...doesn't mean bad, just may be hard to find parts for and everything rots over time so insulation on various things may be on the edge.
You need an AC/DC unit to run aluminum...which is usually the case with transformer machines since they are inherently AC and have rectifiers to convert to DC. The HF is just an overlay current used to start or stabilize an AC arc. The HF switch is set to start for DC work and continous for AC work (unless doing stick and the HF is not needed).
The advantage of old machines is the price...usually pretty good. Check www.ebay.com and search the completed listings (advanced search) to get an idea of what people pay for these things. Getting whole rig that works up front will not blindside you like getting a new machine and finding out that all the other bits and pieces cost a small fortune.
Disadvantages compared to new:
AC is sinoidal. New machines are square wave AC. The sinoidal wave needs the HF overlay to keep the arc going during the wave swing past zero. Square wave is so quick on the switch that the arc is inherently stable.
Transformer machines are heavy (had an Air Products clone of a Dial Arc 250 that was
475#). The big transformers waste power heating the copper wire and iron core. Big fan is noisy. Power requirements are huge, especially on single phase...but you rarely use that sort of output.
A new inverter machine weighs 1/10th. Power requirements is about 1/2 (they don't heat up like a transformer, more efficient). Square wave. Lots of whistles and bells in adjustment, pulse, etc. Big price tag, all the accessories to buy.
Sorry for rambling, hope some helps.
The 250HF is a great machine. It was also sold as the Ltec and the Esab Heliarc 250HF. It is a squarewave machine and most of the parts are still available.
The machine is worth around 1300 to 1500.