Doug's Skills for trade

For those who are willing to help others.
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This is for those who don't mind doing something a little extra for others, using their core expertise, so the other guy can get on with his project in his own field. Barter is encouraged, if it's for money that's fine too, however.

Doug's Skills for trade

Postby Doug Coulter » Sun Jul 18, 2010 1:02 pm

Design consulting, hardware, software, systems, analog, digital, RF -- expensive by the hour, but I am faster than most, and may already have a design
for what you need, which makes it really fast.

Machining -- I have a full basic machine shop and tools and stock -- manual, not CNC, every type of welder known, and can do anything you can do with that setup.
For truly tricky stuff or better than one mil accuracy, you might want to contact Jerry instead.

Glass or quartz blowing if it's simple -- I am NOT a master, but I can get things leak tight and with glass/metal seals.

PCB layout if simple -- I do complex things too but that gets expensive. Think more like CW multiplier boards or small preamps/signal processing things.
Cheaper if I want one too.

Coil winding / ferrite transformers

Electronic equipment repair, refurbishing, calibration

Electroplating in several metals (Cu, Ni, Au, Ag, Cr)
Anodizing w or wo dye, including hard anodizing which makes a great insulator for Al used in vacuum.

Photolith and PCB, the former is crude, the later only a very small quantities unless you cut and drill them -- for more go to
APCircuits -- they are a good deal, fast and high quality.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: Doug's Skills for trade

Postby Jerry » Thu Jul 22, 2010 12:26 am

every type of welder known,


OOoo. You got a friction stir welder, a plasma welder, and a atomic hydrogen welder too!!! :D
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Re: Doug's Skills for trade

Postby Doug Coulter » Wed Aug 04, 2010 12:31 pm

Well, yes I actually do have or make as needed some of those. Guess I should have said "almost" there. I've done friction/spin welding, and have made some really nice little torches for H and O fuel/oxidizer complete with electrolyzer for the gas source.

One trick I do with the TIG is that I made a jig inside a 3" sq piece of steel piping that holds the head and a fat clamped grounded tungsten counter electrode so you can just start the arc and have this nice hot "fire" in inert gas. It is THE best and fastest way to weld tungsten itself, which arose when making type C thermocouples (W/Re alloy). I also made a cap discharge spot welder for that, but this is really superior for that and just anything you want truly hot as the seven hinges of hell....in inert atmosphere. If you can fit it in there. I find spot welding tungsten to not be a real good thing to try if you have a low frustration tolerance. It tends to weld to the electrodes better than to itself. If you can handle the impurity, nickel plating it first solves that one.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: Doug's Skills for trade

Postby Jerry » Wed Aug 04, 2010 9:17 pm

If you are thinking of stir as the friction welding done for pipe and tubing its close but it is a different process. You can do it on a sufficiently rigid milling machine. Whats cool about it is you can weld normally unweldable alloys like 7075.

Oxy-Fuel welding with hydrogen is different than Atomic Hydrogen Welding. Think more like tig and carbon arc. Heres what little wiki has on it:

Atomic hydrogen welding
From Wikipedia, the free encyclopedia
"AHW" redirects here. For the airline based in Kharkiv, Ukraine, see Aeromist-Kharkiv. For the railroad, see Ahnapee and Western Railway.
Atomic hydrogen welding (AHW) is an arc welding process that uses an arc between two metal tungsten electrodes in a shielding atmosphere of hydrogen. The process was invented by Irving Langmuir in the course of his studies of atomic hydrogen. The electric arc efficiently breaks up the hydrogen molecules, which later recombine with tremendous release of heat, reaching temperatures from 3400 to 4000 °C. Without the arc, an oxyhydrogen torch can only reach 2800 °C.[1] This is the third hottest flame after cyanogen at 4525 °C and dicyanoacetylene at 4987 °C. An acetylene torch merely reaches 3300 °C. This device may be called an atomic hydrogen torch, nascent hydrogen torch or Langmuir torch. The process was also known as arc-atom welding.
The heat produced by this torch is sufficient to melt and weld tungsten (3422 °C), the most refractory metal. The presence of hydrogen also acts as a gas shield and protects metals from contamination by carbon, nitrogen, or oxygen, which can severely damage the properties of many metals. It eliminates the need of flux for this purpose.
The arc is maintained independently of the workpiece or parts being welded. The hydrogen gas is normally diatomic (H2), but where the temperatures are over 600 °C (1100 °F) near the arc, the hydrogen breaks down into its atomic form, simultaneously absorbing a large amount of heat from the arc. When the hydrogen strikes a relatively cold surface (i.e., the weld zone), it recombines into its diatomic form and rapidly releases the stored heat. The energy in AHW can be varied easily by changing the distance between the arc stream and the workpiece surface. This process is being replaced by shielded metal-arc welding, mainly because of the availability of inexpensive inert gases.
In atomic hydrogen welding, filler metal may or may not be used. In this process, the arc is maintained entirely independent of the work or parts being welded. The work is a part of the electrical circuit only to the extent that a portion of the arc comes in contact with the work, at which time a voltage exists between the work and each electrode.


Every once in a while the machines pop up for sale. One of the guys on Practical Machinist found one a couple years ago. It would be fun to build one. Thats one hot arc!
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Re: Doug's Skills for trade

Postby Doug Coulter » Wed Aug 04, 2010 10:31 pm

Back in the day (way back, in the '60s) my pal who was into RF and chemsitry and I made a plasma torch, where we made both the H and the O monatomic with the output of a large RF transmitter he had, kind of a big dual RF ionizer. It was hot alright....but I think by that point, as your article says, burning didn't have much to do with it at all -- it was just recombination at that point, and any burning happened after the gases went past the work piece and cooled down enough to actually burn. Probably would have worked fine with either gas alone, or perhaps better yet with N2 which has a real fierce energy of recombination, more than most other gases. It's sure done some strange things here, to the point where I don't play with it for testing ion sources -- when it all gets back together it makes a loud bang in the tank, even at some fairly good vacuum. It would get into a metastable state of some kind and absorb the 10w ionization source I was using for about 10 or more seconds, then, bam -- 100 or more joules, complete with serious EMP and blinding light. H or D do this a little under just-right conditions, but nothing like that.

I always did what little spin welding I did with a flywheel driving the spun part so it would slow down just so and let the weld "make" with the right timing, but didn't do it beyond seeing if it was feasible.
Wasn't worth it for anything I was doing, would be great if you were welding support stubs in a boiler for the pipes (as I saw in B&W's book) -- and needed to do a million an hour.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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