Last night in my sleep I too came up with what I thought was a
brilliant invention.... Patent pending.
Having realized a couple of weeks ago that my OA gas-welding failed
to meet my stringent QC standards, a friend suggested I invest in a
TIG welder. After viewing tons of Youtube videos online
demonstrating the ease of TIG welding I bit-the-bullet and ordered a
machine. The TIG welder arrived a couple of days ago, but it is so
far not what I was expecting.
My problem(s) are that I cannot quite see the puddle; from behind my
face-mask there appears to be very little difference between an
optimum puddle on 4130 tubing and a big hole; I have not yet figured
out how to keep track of where the far end of the filler-rod is
located when I'm hiding behind inside a helmet, etc ...
All my problems appear to be related to seeing what is going on;
things don't appear at all like they do on Youtube.
So my brilliant invention of the wee hours of this morning was to
adapt a video camera to serve as my real-time video camera. Using
digital filtering I could using a camera to monitor my welding
environment. The digital filtering software could use some sort of
non-linear filtering algorithm to show the work area in somewhat
normal illumination, but also display the TIG torch and associated
arc/puddle in vivid detail. It could be software adjusted to meet
the exact melting temperatures of whatever alloy I was using.
This morning I had the wind taken out of my sails ...
http://visiblewelding.com/
http://www.visiblewelding.com/Videos/Alum.TIG.closeup.avi
RBerglund
Not to worry Robin. The key is getting the right face shield
transparency (darkness).
The other thing you can do is increase the ambient light on the work
with a 200 watt spot light. This allows you to see more of the work
before you strike a spark and reduces the contrast after you strike
a spark believe or not.
Also get yourself some magnifying reading glasses and get your face
closer to the weld.
Hang in there it is worth it.
Paul Lamar
Invest in a high quality auto-darkening welders helmet, and an
appropriate diopter lens for your eyes. The harbor freight auto dark
helmet is not up to TIG standards and is a waste of money (fine for
just MIG and stick). It is well worth the investment, when you think
that your welding is what will keep your airplane from falling apart.
Buy a couple of boxes of scrap 4130 tubing (Aircraft spruce
occasionally sells them for around $20 for a 10 or 20lb box) If your
machine is also AC you can get a box of aluminum to practice on
also. Practice, practice, practice. Clean, Clean, Clean your joints
prior to welding. Take notes of your settings and which ones work.
Set the current limit with as little overhead to start your puddle as
is practicable. Once the puddle forms, you will typically back off
on the current, as heat builds up in the metal. Use some preheat to
prevent warping. Weld in still air to prevent cracking, do not
quench!
C. Smith
I'm building a fuselage for a Bearhawk Patrol...have much of it
tack-welded with OA. I enrolled in a night-class in welding decades ago
and have always managed to do an OK job whenever I needed the skill
since that time. I can still do an OK job when the job isn't important,
but as soon as I start working on something that will keep my Bearhawk
off the ground, I start goofing up. I will save my engine-mount for
last :)
My biggest complaint with OA is that when one must come back to
previously tacked and/or welded locations'clusters the steel gets
increasingly oxidized in a very large area, even inches from the weld. I
seriously doubt that 4130 is capable of maintaining its weld-strength
when everything is all crusty from being reheated multiple times. I have
several torch heads, smallest is a Meco
My real reason for buying the TIG is that I have a friend who once said
he'd be willing to help me out, and he claims to be a TIG only guy. Of
course I want to do some of it myself, which is why I've been
practicing a bit the past couple of days. This morning I thought I was
doing better, but I was completely surprised when I took the helmet off
to look at my last bead; there was a nice long neat slot in the tubing
where I thought the bead had formed.
So far I've been practicing on old scraps of EMT. I just cut up some old
salvaged EMT into little pieces, soaked them in a little muriatic acid
for a few minutes to remove the zink, and they look just like new pieces
of 4130. From my amateur perspective, cleaned EMT seems to weld much
like 4130. I do have one of HarborFreight's BEST auto-dimming helmets
(an oxymoron, I know), and it does seem to darken properly, except its
response is nowhere near the 1/125,000 of a second they claim. About 1/2
second would be more like it. I just close my eyes until I hear the arc
starting.
The time delay might be temperature related... Its about 30 degrees out
in the shop right now, in fact there is a still a big snowbank in front
of the shop door and the forecast is for another 2" snowfall tonight.
Thank you ALL for the TIG tips
RBerglund
It is a vision problem. Get a spotlight.
Get a better welding helmet.
Paul Lamar
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