Dynasty stick welds?

[scote]

I have read many posts on the dynasty and am considering buying one soon. I have to ask though, has anyone stick welded with it? Is its arc similar to other miller inverters that I hear so much about?
Hawk, what is the thickest steel you have welded (tig) with the dynasty?
Thanks for the info. This forum has added greatly to my knowledge and ability.
Scott

[HAWK]

scote,

The Dynasty has a nice stick arc. The adjustable DIG control really helps with the 6010 and stainless rods. However, the literature again is misleading. It is speced with "Adaptive Hot Start", but does not really behave like it has it. I think Miller means it has the adjustable "DIG" control, but these are different features. I have welded with 3 different Dynastys and they all stick weld well, just no "Hot Start". No, the Dynasty does NOT burn a stick like the XMT or ALT. It does not have the true "Adaptive Hot Start" or "Arc Control".

I have done 5/16" mild steel with the Dynasty. I am a bit unconventional here with my mild steel welding. I use AC with a 50/50 He/AR mix and run my EN balance up to 95-99%. I know this sounds odd and am sure it will draw some comments that helium is not suited for steel, but there is a lot of new literature regarding new practices welding mild steel with helium and argon with the advanced square wave arc machines such as the Miller Dynasty and the Lincoln Invertech 205. I threw in the red to be fair, but the Dynasty absolutely blows the Invertech away-POOF!

[dseman]

Originally posted by HAWK
scote,
No, the Dynasty does NOT burn a stick like the XMT or ALT. It does not have the true "Adaptive Hot Start" or "Arc Control".

When looking at the V/A curves, I've noticed that both the XMT and ALT allow for a more aggressive DIG then the Dynasty provides. It also looks like the XMT and ALT have a 'dip' or reduction in amperage as the arc voltage increases above 20volts---which should make for one great arc when using a 'whipping' technique.

but there is a lot of new literature regarding new practices welding mild steel with helium and argon with the advanced square wave arc machines ...

OK, now you've really got my interest. Do you have any websites or pointers on where I might find these articles? My guess is that the additional 2-5% of DCEP will help clean the mill scale and give you a cleaner, more mirror-like puddle. I've heard that some of the aero alloys are welded this way. Helium will just boost the heat, but since it too is inert, I'm not sure why some would say this is a problem for steel.

-dseman

[HAWK]

dseman,

I do not think the SMAW arc of the ALT can be beat! Set it up correctly and you can run a 7018 vertically uphill effortlessly. The candle wax drippings are so pretty I hate to chip them. This machine will either whip a 6010 to look like stacked dimes or mimic a tightly stacked tig bead depending on your motion. Yes it can be done with any machine, but the flow it is not the same!

Steel is dirty as is aluminum. It just does not have the problems of temperature resistant oxides as does aluminum. The small addition of DCEP in the AC arc provides just enough cleaning action to make a difference in the finished weld. The ability to increase the arc frequency helps tighten the arc focus as it is widened by the addition of helium. A 50/50 or even 75He/25Ar seems to work well. the higher the helium the better chance of undercut. I have been using an oversized filler with the 75% helium additon.

I first tried the setup when having problems butt welding a very thin electopolished hastealloy using 100% argon and DCSP. Even after cleaning the electopolished coating with Scotch-Brite and Acetone I had brown pinholes in the weld. I am only talking about .004"-.008" total thickness with the .008" being a lap weld. It was suggested to me, by Dave Fisher in TIG applications @ Miller, to try the AC approach with argon. It made a signifigant difference!
I let him know the results and we started discussing thicker steels....

Long story short Dave and Andy have both played around with AC and argon on the thinner steels to get the increased cleaning action. I have been using the process pretty much exclusively on non critical work just to see what goes. I'll check with Dave tomorrow to see if he has the web links and/or articles. I recently read something pertaining to this process, but have not been able to re-locate it yet. Don't think I have lost my mind and usually do not put much stock in new unproven ideas, but this one makes sense. I am still searching for the the article. As far as I know there are no problems accompanying this process such as embrittlement,etc.

If anybody out there has any experience with this, chime in. I should have said there is some new literature out...

[dseman]

Thanks HAWK,
I'm a bit of a knowledge nut and am always trying to increase my understanding of what works and WHY. If you or Dave do have any links that you can find I'd be very appreciative if you could share them.

-dseman

[HAWK]

dseman,

I did find one small piece of 'in print" evidence of what I am talking about. However, it only references "plain carbon,low alloy steels under 1/8" thickness. It shows AC advanced squarewave arc ; lanthanated, ceriated or thoriated tungsten ; and argon shield.

This is found in Miller's TIG HANDBOOK on page 75.

[dseman]

Thanks Hawk!

[HAWK]

desman,

I was once told by a knowledgeable welder helium was used only for aluminum. He was up in years and probably never heard of squarewave let alone advanced squarewave. Back then the 60 cycle sinewave was about the only wave form there was and VTVMs were the means of choice for voltage measurement-I mean old!