Welding Tips and Tricks

Hi all...
I have a Miller Syncrowave 250 acdc at home. Its a great unit and I've been able to do a lot of 316 jbs around the house with it already and the results are beeeooootiful (at least to my eyes).
After watching one of Jodys vids I was wondering about my HF settings.
I would like to do some ally stuff a bit better as currently the results are pretty plain. I have gotten a pyrex kit and lens kit thought which I havent hooked up yet which may improve things.

Q1 - the HF setting on the bottom half of the machine. The manual says "the amount of HF energy etc" but is it a frequency changer or a current changer?
Q2 - there is a provision for a spot timer, but it isnt fitted. Is it something thats available? Is it worth the expense? Is it a pulser?


Thanks

Tony

I weld with a Miller SW 250 DX at work regularly. Nice machine.

I do not have any of the options for pulse, spot-time, etc. The only AC control I have other than current is labeled Balance/Dig. This control does nothing in DC TIG. It serves the "dig" function well in DC stick mode. In HFAC TIG, it is the arc balance control, adjusting the "cleaning" action vs. penetration. I always lean toward penetration, with minimal cleaning, as it's easier on the tungsten (I'll weld 3/8" aluminum with a 3/32" tungsten, but I have free access to helium).

Spot-time is not the same thing as "pulse". It's a simple "on/off cycle for laying down repeated small tacks, as one might do welding thin body panels on a car, or any other thin material where you move around a lot to avoid heat build-up. I've used pulse on aluminum, and it is a big help, especially welding very thin to very thick, but it's not an "on/off" thing. It's more like feathering the pedal, but fast and automatic.

I think i'll take a closer look at your machine on the Miller site... It may have something the DX does not.

Edit:

I looked at the machine on Millerwelds.com, and read your manual. If I have the right machine:

The HF control at the bottom is a three-position switch. "Off" is for stick welding. "Start" is for DC TIG (preferably with a pedal or other remote with at least on/off control). "Continuous" is for welding aluminum on AC. You should definately have a remote for aluminum. On/off is okay, and several people prefer it (TamJeff does amazing things with anodized aluminum with just a push-button), but as you learn aluminum, a pedal may make things easier, as you have full control of your output current.

Steve S

Thanks Steve...

I wont bother trying to find a spot switch kit then for it. I can "pulse" with the foot pedal enough for my applications.

The HF question was about the rotary know in the low section of the welder. (Where the cables are hooked up)
Its something that is described as HF energy and to use the least amount as possible (to avoid interference with other devices?) while still getting the arc start-up on AC.

Interested to know if that rotary dial is a frequency changer or something else.
That would be handy looking at the effect that frequency has on AC welding on ally with the focusing of the arc etc.


Tony

It's not frequency, there's no freq adjustment on transformer machines AFAIK. It's voltage for the HF arc. More voltage means more RFI which means more chance of weirding out the computer in the office S/F....Ken M

echosixmike wrote:It's not frequency, there's no freq adjustment on transformer machines AFAIK. It's voltage for the HF arc. More voltage means more RFI which means more chance of weirding out the computer in the office S/F....Ken M

Thanks for that. I havent really experimented with it, but I've never had any complaining from up in the house from the missus that the TV's gone funny when I fire it up on AC, so I guess there isnt much RF leaking out of the whole situation.

Regarding RFI....

I also have a Miller Sync 250 in my basement shop. My house has AT&T "UVerse" that supplies high speed internet, TV and Telephone service to my house. When I start to weld in DC, the high frequency arc-start system runs until I get an arc.... and shuts down my UVerse modem. I loose internet, TV and telephone. The UVerse system takes a minute or two to "reacquire", settle back down and work again. I have things grounded well but do not have a 'Faraday cage' of any sort around my welding area. I have not used AC yet (I am a newbie) but expect the same result.

I found this out the first time I used the machine. My wife was on the phone upstairs talking away. I started an arc and then I heard "Hello, hello, hello...?" coming from up stairs. oops

I understand inverters don't have this problem. (Or maybe not as bad.)

Dan

Have a Syncro 250 issue, maybe someone has experienced it before. Was doing a repair on a RC plane muffler. .045 aluminum. 1/16" thoriated, pointed, 15cfh, #7 gas lens on a -17 torch. It's a 3/4" tube butted into a 1&1/2" expansion chamber, it had cracked at the joint from years of vibration. Focussing the arc was a cast iron bitch. 100 amps on the panel, foot pedal control, and when I got down into lower amperages to maintain the puddle, the arc started wandering all over the place. The more juice I ran, the more it would "center" but I started blowing away the material and stuffing the puddle full of rod to cool started to look like ass. Any ideas? I suppose I could pick up some pure/green, but is it really that significant? I have hundreds of 1/16 thoriated to use up S/F.....Ken M

What are you using for a 'ground' ?
Try Jody's trick of wrapping some copper wire around the tube and grounding to that.

Maintain Focus, Stability
In addition to causing various weld puddle troubles, contaminated tungsten is also the leading cause of an unstable arc. It doesn’t matter the original cause of the contamination—poor shielding gas flow, touching the base material or leaky hoses—but what does matter is how it’s remedied.

First, remove the tungsten from the torch, clip the end and regrind it. An important rule to remember: always grind the tungsten lengthwise. Do not grind around it, as this causes ridges on the tungsten and will also lead to an erratic or wandering arc. Also, grind a taper on the tungsten that spans the distance of no more than two and a half times the electrode diameter. As an example, a 1/8-in. electrode would have a taper 1/4 to 5/16-in. long. Remember to use a grinding wheel especially designated for the purpose of grinding tungsten. Doing so helps avoid further contamination that can adversely affect arc (and weld) quality.

Having too long of an arc can also cause it to become unstable and/or wander on both AC and DC applications. In both instances, shorten the arc by moving the torch and tungsten closer to the work piece, taking care not to touch it.

Dirty base materials and shielding gas are other potential causes of an unstable TIG welding arc. Remember to wipe the material free of oil, dirt or debris and to wire brush materials like aluminum before welding. Be certain to use clean, pure argon for TIG welding (or reduce helium percentages if using a mixture) and keep the flow rate between 10 and 20 CFH.

When TIG welding using either AC or DC, select the appropriate size and type of tungsten for the given amperage to avoid arc-starting problems. Too large of tungsten for the given amperage can cause the arc to rotate around the tip, while too small of tungsten can melt and cause the arc to become unstable. Always follow the manufacturer’s recommended welding parameters for each tungsten diameter.

2% ceriated tungsten provides good arc starting at low amperages and can be used on both AC and DC applications when welding carbon or stainless steel, nickel alloys, aluminum or titanium. The same is true for 1.5% lanthanated tungsten. For higher current applications or low-amperage AC applications, 2% thoriated tungsten provides good arc starting. Note: Thorium is radioactive; therefore, you must always follow manufacturer’s warnings, instructions and the MSDS (Material Safety Data Sheet) for its use.

A final means to remedy arc-starting trouble is to be sure the ground clamp is secure and check that there are no loose or damaged cables leading to it. Keep the torch cables and work cables as short as possible, while still being able to reach the work area, and place them close together. Check that all power cables have been installed according to the power source manufacturer’s recommendations.

echosixmike wrote:Have a Syncro 250 issue, maybe someone has experienced it before. Was doing a repair on a RC plane muffler. .045 aluminum. 1/16" thoriated, pointed, 15cfh, #7 gas lens on a -17 torch. It's a 3/4" tube butted into a 1&1/2" expansion chamber, it had cracked at the joint from years of vibration. Focussing the arc was a cast iron bitch. 100 amps on the panel, foot pedal control, and when I got down into lower amperages to maintain the puddle, the arc started wandering all over the place. The more juice I ran, the more it would "center" but I started blowing away the material and stuffing the puddle full of rod to cool started to look like ass. Any ideas? I suppose I could pick up some pure/green, but is it really that significant? I have hundreds of 1/16 thoriated to use up S/F.....Ken M

I was grounded directly to the part using the nice solid coppper Tweco clamps that used to be standard on Miller machines. The part was extensively cleaned w/acetone and SS brush. Tungsten was properly ground on a SiC wheel dedicated to tungsten grinding exclusively. I can't speak to the brand of the tungsten, but it's some older stuff, so I doubt it's chicom crap. I was using a tight,tight arc. I did snuff it in the puddle a couple times trying to get the arc to stabilize, but I switched out for a fresh tungsten when I did, I've got dozens of tungstens pre-ground. This was a favor for a friend of my father on my day off, so no rush, no pressure. That's why it was kinda frustrating.

After this job I went through the machine and completely examined the ground cable, the clamps, the connection pads on the machine itself. I sanded anything that looked suspect to bright shiny metal. I pulled the HF spark electrodes out and completely cleaned them and regapped them at .008. I think I'll pick up some 3/32" pure from the LWS to try also if cleaning doesn't resolve the issue. S/F.....Ken M

What about gas...

At very low amps, the arc will follow turbulence in the gas stream. My gut reaction (assuming the gas lens is clean) is to increase stick-out to 1/2" to 5/8", and up the gas to 20-25 cfh, and see what happens. Have a look at the gas lens, though. Any crap stuck in the screen from a weld that popped back or "puked" will disturb the flow. At the lowest amps, the flow needs to be really smooth.

Two cents...

Steve S

I have actually welded one of those RC expansion chambers before and it was cracked as you say yours was. I used 1/8" pure, and manually pulse welded it at around 125 amps. 125 is somewhat squirrely on 1/8th" pure, but the pulse lets you out of it before things go wrong. I also built a t-knob for a Penn deep sea reel I have, using about the same setup. 3/32 would work better, but our shop is one of those, one size, fits all kind of places.

Agree with Steve about extending the tungsten out past the cup a bit for better arc focus, although, I do not use a gas lens.

I have a SW 250 and mine has the same adjustment and it's in the same area that the HF points are located. Setting is continuous from 0-100% IIRC. Mine is set at about 70 for anodized. I can drop it way down to say 40 for mill finish. I don't really notice much difference either way, because I often forget to set it back, but it was noticeable on the smooth wave machines like the Miller Aircrafter. On those, they liked running full tilt on anodized.

Which reminds me, I am probably due for a new set of points by now, or at least chuck these up in the drill press and clean them and reset them.

Not sure about the gas lenses, I'll experiment. I was half peddle, probably 40-60 amps, I would have thought that would be fine for 1/16" tungsten, as that's not low amperage. AC balance was set at 7, which Miller says is about 30% EP.

I picked up some pure 3/32 and 1/8 from HTP America, they're about 10 min from my house, which is convenient as all hell. I've got some 1/16" flat stock I'll putz with Sunday morning, do some butt welds and such. Thanks. S/F....Ken M

Well, not sure about what did it, but things were much better using 3/32" pure with a flat ended taper. I didn't bother checking with the thoriated, so it could have been all the cleaning and sanding on the ground clamps, points, etc. S/F.....Ken M