I hope you don't mind me weighing in. I am a former owner of an ABI
machine (and completely agree with Jim, I'd never buy one again), a
former owner of a PUK II, and a current owner of an RDO. After having
owned all of these machines, I'd unequivocally give "the nod" to the
The RDO does have more power than the PUK II. This makes it easier
to weld the more difficult materials out there, and is especially
handy with welding silver.
I've found the RDO easier to use than the others (easier than the
ABI, because the RDO actually works, and easier to use than the PUK
in the short term, but the PUK does get easier to use the more you
use it). This even takes into account the fact that the instruction
book is pretty terrible for the RDO. You can see what you are doing
with the RDO. The RDO uses an optical shutter arrangement, while the
PUK uses a welding filter. With the PUK, you are always looking
through the darkened (has a green tint) filter while you are getting
ready to weld - I found this a tremendous pain in the butt when
trying to use the 'scope with it. The RDO has a clean, well lit,
clear view. Initial units (mine and one that Jim used) had shutters
that did not work 100% - a dangerous situation. This has been
corrected, and they even sent a repair tech to my studio to install
a new board - great service! The RDO allows for user input, as well.
(argon pre-flow, power, weld duration) Another huge benefit of the
RDO (and lasers, and the PUK with the optional torch holder), is the
foot pedal operation. This allows you to use both hands for
steadying of the workpiece.
The RDO also produces multiple welds quickly, cleanly and
efficiently - easily allowing the stitching of multiple welds
together. Power is constant, and does not "drop off". An air nozzle
makes cooling your work frequently very easy, saving you the cooked
fingertip feeling when doing multiple welds. In order to get this to
work, you need a compressor - it's not necessary to the function of
the machine, but is a nice comfort feature! You simply connect the
compressor to the machine. The RDO is in it's own "box" - this allows
the argon to puddle, so you can get nice clean welds, and even work
on titanium successfully (eyeglass frame repairs are easy). But,
this does limit you to what size item you can stuff in the box and
weld. Angle of "attack" can be difficult with the fixed torch, but
they do have a ceramic insulator that you can slide over the
tungsten electrode, allowing you to be very creative when
positioning work to weld.
I have a friend with a laser welder (a Rofin) - he used to get all
of my welding jobs. He doesn't anymore. I have not found a job yet
that the RDO can't handle (I am sure they are out there). It has
definitely helped me with some difficult fabrication problems. Every
time I use it, all I can do is think of more things to weld with it!
I have recently heard about "laser polishing". I am not sure what
this is, but the RDO does not seem to polish anything! Also, lasers
do require maintenance - so far, all the tig systems I've used only
require sharpening of electrodes (save the optical shutter board
replacement - hardly "routine" maintenance).
And not to take away from the PUK II - it is a great machine, but
does not work as well as the RDO in many of my situations...but, it
is less expensive, and having the "pen" style torch does allow a lot
of freedom in how you approach larger objects. It also is well made,
nice looking, and takes up less studio real estate than the RDO. I
know Jim loves his PUK II's.
But if you have the ability to, I'd buy the RDO in a second.
Gesswein is the distributor - Elaine Corwin can answer any technical
questions you may have. At RDO, the "main man" is Bob Okner. I even
think they are having a sale now - I remember a big poster at the
Providence MJSA show.
Chris Ploof Studio