TIG Welding Amperage

First let me state that I am not a professional welder. I do get by with the welding that comes my way, but I am not an expert.

We purchased a Syncrowave 250 about 20 years ago. If you enjoy welding, you will love that machine. The amp setting may not go low enough for your desires, but remember that the foot control will only allow a percentage of what your amp setting is. You will also be able to hold the torch a little further away to lower the heat.

If you don't have a auto tinting welding mask, get a good one, it makes the delicate work much easier.

Do you have a local salesman to work with? If so, get some of the thin material and have him show you the best way to achieve your desired results. Good luck, and enjoy that welder. I love mine. If you get near South Fla, I would be happy to let you play with my welder.

To all who responded, thank you!

It was a generous and much appreciated response, especially the offers to let me play with welding equipment. To Bob C: Thanks for those encouraging words about the Miller Syncrowave 250. I feel a lot more comfortable buying the machine, which while used, but rarely and in excellent shape.

I'm a Mechanical Designer by trade and while I have developed skills in advanced composites and machining, my designs were still limited by my inability to weld when welding would have proven a better solution.

Thanks, everyone!

L.J.

If you have gotten a hold of my welder, I am not going to be a happy camper!

I am willing to bet that you will be able to write your name in script in less than 2 days. Enjoy it.

As a former Miller service tech I can tell you I don't know much about them from hands on experience. They never brake down so I never got any good opportunity's to take one apart! Seriously they just don't quit!

Now the Miller inverter welders... Those pieces of shit I can rebuild blindfolded while hanging upside down. If you told me you had one I can tell you what went wrong before you even mention its actually broke!

If I ever had a justifiable reason to buy a dedicated TIG machine the Miller SynchroWave would be it!

Can you draw and maintain a welding arc under 10Amps? Even if it's TIG 10amp or less just sounds very low.

In any case you should talk to the dealer and find out everything including if you could return it in case it's not suitable.

You can certainly maintain an arc under 10A. All of our welding is on small items in stainless or nickel alloy steel probably 1mm thick max & down to 0.1mm. Obviously our TIG welders are machines designed for this sort of duty & are much smaller that the norm.

Hello Nigh, I have a couple of question I would like to ask you. Are the machines you all use to weld this thin material available for less than $5 K? Could you give the brand name or any other info. on the machines you all use? I am very interested in purchasing one if it turns out I can afford it.

I'll check that out, the machines are in our main clean room.

Sorry for the delay in replying, we lost our internet connection at work. there seems to be a Friday conspiracy, last week we had a total power loss at about 11am & ended up going home mid afternoon.

The welder is a Miller Maxstar 200, we have the machine only with fool pedal control & use thoriated tungsten electrodes. The welding is done either freehand or using a powered turntable.

I was out all day repairing boiler tubes and didn't get a chance to ask if you all use anything special with the Maxstar 200 in order to weld the super-thin materials or will it just weld at the low amps needed. Today i was working repairing tube that started out at .095" but were pitted so bad that they were below .040 and even down to .000" in some places. I used a regular dry rig, and 1/16" tungsten and 1/8" 70s-2 TIG wire and although I would burn through in places and have to bridge the metal back in the tube they welded pretty good. It is kind of funny that I know how to make and ASME repair to old, junky, corroded thin, boiler tubes but can't make a decent weld on thin s/s counter tops. A few years back I talked a to a guy in California that builds his own special welding machines made to weld the paper thin materials. The company will send a welder out with one of their machines to make the welds or they will sell the machine alone. He said that it could sustain an stable arc as low as 1/2 amp for manual welding and even lower for thinner materials in an automated process. I remember he had a very impressive set up as well as very good references of completed work on thin materials for clients all over the world and they were welding stuff like aluminum beer can thin. If I remember right he wanted 16000.00 for the bottom line machine which was way to steep for me. I can't remember the company name because to tell the truth after he told me what he wanted for his machine I pretty much gave up on welding super thin materials. At those prices I and happy to just rely on either silver solder or brazing to join the thin stuff like I have for the last 30 years.

I would say 90% of the time we weld with no filler. We mostly have weld preps machined into components but with the thin stuff we just edge weld.

You'd be very happy with the Synchro Wave. However, I can't imagine welding at anything close to (as low as) 10 amps. Even light aluminum soaks up a lot of heat, and therefore amps. If you are a good gas welder, TIG will feel much more natural to you than going from stick welding to TIG. Have fun.

I have to agree with you. It seemed to me to be similar to gas welding. The books also refer to the tungsten holder as a torch.

Don't worry, tig & torch are similar.

external heat with filler rods.

The hard part is going to get the initial set up

Here's a manual it will help you understand the settings

Aluminum is tricky, must be clean. preheating helps & you already have a torch

sometimes ac is good for aluminum.

starting is the hard part, practice on something thick

the way the electrode is sharpened, changes the shape of the fire...

I think it's easier to learn with a thumbwheel control.

The watercooled foot pedel is great for sit down production work [long welds] on thick stuff.

Wear protection, tig gives a wicked sunburn, you'll get one on your neck in no time

Mig [wire welding] is the easiest to learn.

arc is great because it has the flux,

Sign up at the Miller Welding forum:http://www.millerwelds.com/resources/communities/mboard/

Lots of helpful, knowledgeable people.

I voted you a good answer... but this is well beyond a good answer. Great stuff!

GA from me too. Great posting.

Hello Awhile back I was offered a job of installing/welding thin 20/22 gauge S/S counter tops and found out that my machine would not sustain an arc at the super low amperage required to do this job very well. I tried all the things I could such as using small diameter tungsten and filler wire and finally worked through the job with decent results but it took way longer than it should have. Although it was a parts counter and did not have to be flawless it was not the caliber of quality that I am used to producing. At this time I checked into buying a low amperage welding machine made just for welding very thin pieces and after hearing what the guy wanted for it I decided not to get one. I guess building a machine that can sustain a usable arc down to 1/2 amp must be pretty hard to do. I could have literally bought 4 of the Miller machines that you spoke of for less than they wanted for this machine.(I think it was in the $15K range for one machine) I checked on the internet and in many other welding shops and supply houses for a cheaper machine or a way to make one of my machines go low enough to weld these thin pieces correctly and finally decided to let someone else have the headache.

I by far would recommend a 300 amp Thermal Arc TIG/stick inverter machine for carbon steel and S/S TIG or stick welding and I think that they have them with the high freq. for aluminum and such. This little machine and a 150 amp Tweco WP17V dry rig and a bottle of argon will do just about anything you need. I own 7 or 8 different electric machines that will do just about any type of welding. My experience is mostly on code pipe and vessel work and although I work as a project engineer during the day I fit and weld x-ray piping nearly every night. I own a 1984 a Lincoln pipe liner motor driven machine with aluminum windings that I welded with in the oil field refinery/chemical plants for many years. I always thought that this was the sweetest welding machine I had until I bought the Thermal Arc inverter and it literally blew it's doors off with both stick and TIG welding. The 300 amp machine I have weighs only 48 pounds but it has an adjustable arc control and hot start setting that will tune in most welding jobs perfectly. I have Miller, Lincoln, Pow Con and a couple other brands in my shop and although they all get the job done the Thermal ARC machine welds better. The Lincoln and miller dedicated TIG machines are very nice but for most TIG welding on S/S , nickle alloys and C/S these features including high freq. current and a water cooled TIG rig are just not needed. I learned to weld aluminum alloys and titanium on a Lincoln TIG 250 and you do not have to get a machine with all the bells and whistles mentioned in order to make sound TIG welds on these alloys. However if you do understand the technology and have plenty of funds they will weld certain alloys better. I use a Miller 300 multi purpose machine with a Miller high freq add on box and a miller water cooled torch set up to weld most anything including the non ferrous material other than titanium alloys. If you are planning on welding allot of x-ray quality titanium then you need to really have a clean room and dang near purge it with argon to make consistently good production welds. If this is the case I would go for the fancy machines with the pulsed circuity and adjustable wave high frequency and maybe even a butt wiper for kicks and also plan on spending big bucks for trailing rigs, purge paper and tape and other backing gas containments and even HEPA vacuums to keep the dust off of everything. Titanium is so touchy and complicated to weld correctly that it is not worth the trouble unless you looking at getting a huge contract. I have seen many beautiful 100% sound titanium welds that passed x-ray be rejected just for being the wrong color which basically means the weld and HAZ has been over heated. In the truth if you just want a welding machine to do jobs around the house as well as the occasional industrial piping weld at cost around $2200.00 or less there are probably hundreds of machines that would do the job well without being so complicated that you have to spend years to learn how to use them. If you can get by with less than 300 amps welding current Most all the big companies have lower amperage rated models for much less that weld good. I would defiantly suggest you at least check out the Thermal Arc inverter machines if you are an experienced enough welder to be able to tell the difference or just learning to weld and want a good machine before you decide.

Spent 6 years behind a HOBART CyberTig 120, alu, stainless, titanium, tool steels ect. Cannot look back, so if an unlimited budget is on hand and you can get hold of one, this machine gets my vote(ps tried many others too). BTW 300A all the way down to 3A, yes 3A! welded two pieces of alcan foil together.

....i know service techs for Miller hate the inverter machines, but these can ghold a stable arc at a fraction of an amp.

i think the reasons these machines break is because people use them for larger jobs than intended. i never had any issues, nor did framebuilders i knew with the Miller 90 or the one just above that, which was the 120 or 150 inverter...can't recall right now. there is a matched pulser available that is awesome, anf the 90 plugs into a standard 110 wall outlet, and is light enough to carry in one hand (gary helfrick who pioneered welding titanium outside a bubble used one of these with a composite firemans tank on his back for his shielding gass...

if you are doing precision work, these are the best i ever used.... make sure you are prepping your tungsten precisely, and that you use a large gas lens, with just enough flow...most people set the flow too high which blows a fracional amp arc around or out.

benbenben

Might look into the new HHO or "Brown's Gas" welding equipment. A manufacturer in Korea is making Brown's gas generators and I think they may also have safe nozzle systems for use in welding. I found a link in YouTube.com when I looked for HHO welding, can forward the link if you have some interest. The advantage of HHO welding is that it has zero fuel cost; the fuel is water which is broken down into HHO gases (H + O in one output pipe, not combined into H2O); this gas when oxidized in normal air is said to adjust itself to the required temperature to melt the metal. As I understand it, HHO or Brown's gas does not burn at a certain set temperature but will increase temperature when burned and focused on a particular material. I haven't tested this out but it sounds like it might apply to your needs quite well. I hope this is of interest.

I posted this welding info earlier before logging in. You can write to me via this handle .. for the Korean manufacturer info I mentioned. I don't know what manufacturers in the USA might be making the HHO or Brown's gas generators and welding kits. The Korean manufacturer is the first established manufacturer I had noticed which is producing these systems. I hope this is not considered "off topic".

Ga for an accurate and interesting post.

Way back in welding school we were taught that the hottest known flame that could be achieved was oxy acetylene neutral flame and it could be adjusted to get up to 6300 degrees. This a mix of gases of course and the oxygen is the key for it to make the high temperature. Are you saying that hydrogen gas can reach temps. of 6000 degrees alone without adding oxygen to promote the flame? If this is true then you would think you could do wonders with this sort of heat for welding. Any conventional cutting torch gas I have ever used (acetylene, mapp, propane etc.)requires compressed oxygen to accelerate the heating of the metal as well as oxidize the molten metal and blow it out the other side, I was assuming that the hydrogen welding torch used oxygen as well.

Are you saying that hydrogen gas can reach temps. of 6000 degrees alone without adding oxygen to promote the flame?

Hi Pipewelder. No I'm not saying that. The oxyhydrogen welding units (the electrolysis-based ones) create a nearly perfect stoichiometric mix of H2 and O2. They are really just an electrolysis unit with the gasses collected together instead of separately*. As you can probably guess, collecting them together is actually easier than collecting them apart... in fact, if you just stick two wires into water with a tiny bit of lye in it, and collect what bubbles up, you're done... more or less. As you can also guess from your experience with acetylene, the mixture is apt to light with a bang, just like an oxyacetylene torch does if you turn both gasses on before lighting it (which your instructor probably told you was not a good idea... although I often crack open a tiny bit of oxygen, just because I don't like the soot.) So with an (electrolysis-based) oxyhydrogen torch, you have no control over mixture -- it is always set for a perfectly clean flame, just by the nature of the electrolysis process. After the torch burns x amount of the two gasses, you end up with x amount of water vapor in the atmosphere.

*This common collection would ordinarily be considered a safety hazard, because all it takes is a tiny spark to make a loud bang. The oxyhydrogen welding machines have special protection against flashback. As you know, with a standard welding torch, the flashback can only travel to the handle valves, because the acetylene needs O2 or air to burn. But in an oxyhydrogen torch (assuming it is common ducted -- not all are) the flashback has the potential for blowing up everything back to the electrolysis tank -- if it weren't for the fact that good ones are designed to prevent that.

One way to prevent flashback is to be sure that the tip size is small enough to keep the gas speed higher than the flame front speed. The Arizona Hydrogen people, I noticed, mentioned tips as small as .003 inch (a hole about the size of a human hair). A tip that small keeps the speed high even with extremely low flow rates. Practice a little, and you should be able to easily weld up a set of horse shoes for a horse fly!

I was assuming that the hydrogen welding torch used oxygen as well.

Some can. Some are just like an acetylene torch... tanks, regulators, etc. The ones that the guest brought up are sometimes called water torches (electrolysis based) -- and they are not very good for cutting, because they don't actually burn the metal, they just melt it -- and they don't have the advantage of a lot of oxygen to blow the cut clear. If you wanted to cut with hydrogen, you'd use tanks, and it would work just like the other gasses you've used.

Sorry Nigh, I went back and saw where I'd missed the oxygen part. The web site was very informative and I appreciate your posting the link. The lower end models are expensive but not out of range of most people. I would have to try one first before spending that kind of money though.The torch I saw the guy use was supposed to do heavier gauge welding and it didn't work other than lighting off a couple of times. The man kept working with it but the flame I saw on the torch was really puny and was not hot enough to get a weld puddle started on thin material. He had told me he was working on developing a cutting head for the torch but by that point I was doubtful. I had to wonder just how honest a fellow he was after seeing the demonstration he tried to put on. Now that I think about it I may have watched a jeweler use a oxy-hydrogen torch to braze on an item before without knowing what it was.

GA.

Does this mean that I can weld with my car after I convert it to run on water?

You have mentioned of welding 6000 series aluminum up to 0.25" and 4130 Chrome Moly up to 0.25" both being lower gauges.

It can be done only by Pulsed TIG welding process (in general) using a lower range of amps.

For Aluminum you require AC and for Cr-Mo Steels DC currents . No separate machines are required and you can buy a AC / DC Pulsed Power Source if it is not a high production requirement. Air cool torch is sufficient and no need to go for water cooled torches in both cases. Parent materials could be (being thin sheets) fused directly.

If the productivity for both type of metals are high there is no other option but to go ahead with two separate power sources. 160 Amps - Pulsed TIG Welding will be ideal for your use. The advantage being current adjustments to min. 5 -10 amps to suit your needs.

If you contemplate a heavier gauge in future fabrication, you can go for 200 - 250 amps capacity power source , but at the cost of lower power range in the equipment. i.e. if the capacity is higher, you have to sacrifice the lower range of amps setting for welding thin sheets. Hence , please check up your future plans also and decide.

If required , you can request for demonstration of the Welding machine (from the manufactures) and Practically weld sample jobs before deciding upon the right type of Equipment.

Both being thin sheets, setting should be between 20-30 amps or so for 4130 and for Aluminum it could be app. 1.5 times more than the Cr-Mo steel because of faster dissipation of heat during welding and to also to get full fusion and penetration.

The actual setting of current also depends upon the other variables like travel (welding) speed , Welding Position, Automation etc. However I assume the positions to be to be Flat to Horizontal .

Other precautions being, use of lower size of Tungsten Electrode ( 1.00 to 1.50 mm size), a lower range of gas flow rate for your amps setting ( to save gas and avoid wastage) and using SS wire brush for both materials.

Trust above details will help you to start well with your project.

Sridhar.

the only significant group i know using HHO to join metal, would be jewlers. i know other industries have the occassional statistical outliers that opt to use HHO cutting torches.

i bet an HHO system would be great for brazing fitting in an area where ventilation was limited.

i doubt an HHO system would be very useful in creating precision welds on thin high strength work pieces. you might be able to develope a high temerature, but it would not be compact enough to be precise.

moreover, O2, H2, and steam, are incredible bad things to allow to contact high strength alloys at elevated temperatures. it actually makes me cringe a little. Titanium va-al alloys become very hard and brittle (hydrogen embrittlement) when insufficiently protected at elevated temperature or pressure. this happens far below the melting point.

benbenben

This has proved to be one of the best recent blogs that I have read.

I learnt to use normal arc welding equipment 46 years ago in the RN, though the actual times I have used it are few and far between (sadly).

I also learn learnt Oxy/Acetylene torch welding (my favourite up till recently).

Also gas brazing and soldering.....

A couple of years ago, to speed up some fabrication work I needed in SS, I bought myself a hobby MIG welder. That has been a real lot of fun and very, very useful, though I have to admit my welds are physically strong, if not quite as pretty as they could be, but I am working on that, but at least I am now up to speed with welding SS and normal steel and aim to try aluminium fairly soon.....

TIG sounds very interesting and similar to torch and I was wondering if it is possible to make something that can use the MIG unit (that I already have) with TIG welding techniques, or must a complete new machine be bought, which I won't do by the way.....or not until I win the Lottery!! I would like to be able to do either, with a switch (if thats possible!) between the two and a change of torch etc!!......

Also do we have a welding Blog in the Hobbies section? (I haven looked, but not found anything that directly reflects Welding), but if we don't, we should have......it appears that we have enough experts to answer our questions!!!

Maybe we should have a seperate blog for each type of welding.....

What do the rest of you think?????

Sounds good, it's not a bad idea.

Initially could be called 'Welding Engineering' that can later brake into its respective categories as it goes along, unless it's easier for CR4 admin to create them in the beginning.

Later, however, there might be new welding methods come along that could expand the blog.

I don't know about TIG welding with the MIG, but when I got the TIG, I was told that I could buy a wire feed attachment for it.

Sort of doing it the other way, very interesting....perhaps someone can add some extra detail.

TIG sounds very interesting and similar to torch and I was wondering if it is possible to make something that can use the MIG unit (that I already have) with TIG welding techniques, or must a complete new machine be bought, which I won't do by the way.....or not until I win the Lottery!!

You'd have a good time with TIG. It is fairly easy to get up to speed with a good TIG machine. If you go from stick to TIG, the ability to start the arc with a foot pedal is a revelation, and makes it easy to be much more precise. You've got great control over the puddle, the weld comes out very clean, etc. I used to do a fair amount of TIG when I had access to the equipment, and it made me feel like a hero -- great looking welds, pretty easily. I'm older now, and don't have access to a TIG machine, so I have others weld aluminum for me. I use a wire feed welder for steel, and it is fairly easy to use (and LCD masks make things easier, too) but my welds mainly look horrible, at least if I am welding 1/16" thick material, which I have been doing a lot of lately. Age has given me worse eyesight, and perhaps less steady hands... although the main factor seems to be vision. (I suppose the saving grace here is that eventually my eyes will get so bad that I won't be able to see how bad the welds look.)

I've never done it, but it is possible to scratch start or lift-start TIG, (and therefore maybe you could convert a MIG machine) but, for me at least, one of great things about TIG is the ability to stop and start the arc so easily and precisely -- which (at least when I was using one) required a high frequency starter circuit. I think you'd be happier with a purpose-built machine. You can probably find a welder who would be happy to show you the ropes and who would let you try out his machine. You'll get hooked. If I did enough aluminum welding to justify the cost of a TIG machine, I would certainly have one -- as I said, the machine makes you feel like a hero... even if, like me, you are not a stunning welder.

There are people who weld aluminum with a stick welder, using rods that create their own shielding gas (which might better be called smoke). The welds are functional but not pretty, and the material needs to be relatively thick so you are not constantly blowing holes through it. The process does not appeal to me at all.

Many thanks for your interesting comments. I did not realize that TIG units have extra circuitry to start the arc.....a purpose built unit would be best, so I will have to see how my pocket money works out for next year!!!

The beauty of a tig machine is

Lay down some ugly mig beads & go over it with the tig, looks just like you know what you're doing

I used to do plenty of that for food processing equipment [ss].

another good SS sheetmetal trick is to tack it together on the inside with mig & weld it on the out side with tig.

For doing sheetmetal butt welds [such as extending a guard], clamp a piece of 1/4" aluminum flatbar inside, keeps you from burning through or warping as much.

To repair say an aluminum handrail. Take an arc welding rod [aluminum] knock the flux off, a bit will remain. Use it for a filler rod & tig. The small amount of flux really helped on dirty stuff.

On some machines you can use the foot pedal to control the start/stop on the stick section. I used to use a miller tig/stick machine like that. we left both sets of leads hooked up & had insulated nests to store them in. We never knew what was going to break or which machine would be needed at a moments notice.

The above are just some things that worked for me over the years, may not be proper procedure

repair say an aluminum handrail. Take an arc welding rod [aluminum] knock the flux off, a bit will remain. Use it for a filler rod & tig.

Using a flux knocked bare rod for welding of aluminum hand rails is OK as it is just a structural weld- joint and does not call for any strength like factors.

But, such a practice is not recommended while welding any pressure part (or) where corrosion, high And low temperature service is a criteria where and where Chemical and Mechanical properties determine the end application due to following factors.

a. All Carbon Steel electrodes are made of Rimmed quality Mild Steel core wire and has limited quantity of Manganese & Silica. All additional de-oxidizers like Mn, Si and other alloys like Cr, Mo, Ni, V are added in the flux coating only to get sound welds and to meet high strength (E 7018, E 8018 to E 13018 etc.) requirements.

b. All low and high alloy steel electrodes are also having same above MS core wire only and additional elements, to get high & low temperature service applications are added in the flux coating in the form of Ferro alloys.

c. Similarly most of the SS electrodes are also synthetic and the core wire is of 304 type and additional Chromium, Nickel or Moly are added through flux coating and to get required Chemical properties suiting to E 309, E 316, E 310 , E312 etc.

d. Same is the case with Al+ Si, Al+ Mg type (Al core wire), hard facing (MS core wire) electrodes etc.

e. Since the final Weld Chemistry and Mechanical Properties are important, the alloy additions may vary depending upon the chemistry of core wire.

These details are pointed out, just in case any fabricator use core wire after peeling off the flux and replace bare filler (like ER 8018 B2, ER 9018 B3 or ER 308, ER 316 etc.) rods generally used in TIG welding process for a crucial manufacture / application. Sridhar.

Don't let hand tremmors or shakey hands get in the way of precision welds....

Almost everyone has small tremmors and shakes, and on very small work requiring precision, it would seem to be a big problem, but bracing is the very effective solution. Surgeons do similar dexterity tricks too....

basically, without your hood, and certain you wont flash yourself, consider, asses, choose and practice, various fluidly mobile support for your torch hand for the pass you are doing... later these become automatic.

Often your filler feel hand has 3 fingers not in use. Anchor that wrist on something stable and neutral to your path or path axis. straighten the previously unasigned fingers to form supports that can pivot (think of a 5 point suspension links on your car wheel), and provide a steadying base upon which your torch wrist can pivot WITHOUT RESTRICTION OF MOVEMENT NECESSARY for the pass.

The close you can brace the more steady... also the better chance you roll a wrist into somewthin hot enough to imagine your heard it singe before you felt it.....

You can also brack wrist over wrist, torch wrist on knee, upper arm, ... you get the idea.

Also if you can see it well when you are practicing the bracing for the pass, it might be easier to navigate even if you can't see it as well when your hood is down doing the actual pass.....perhaps this will help with vision problems you are experiencing?

BENBENBEN

Vision problems are as good as fixed with good strong lighting and an LCD mask......I cannot imagine there being anything better.....but I am willing to learn if there is.

Why we are on the welding subject and have the welder types rounded up I am having a problem with my FCAW set up that I could use help with. I am using ESAB .045 and 1/16" OD wire and a 75%argon25% carbon dioxide mix for a shielding gas to weld 1/4" to 1/2" thick SA-36 plate. I am doing this welding on a Miller shop-master 300 on the constant voltage setting just like I always have in the past with no problems. I was building a small a small API atmospheric pressure vacuum separator / silencer that works with the exhaust of two large roots water seal vacuum pumps. I really do not like to use bare wire MIG GMAW welding on tanks (other than outside legs and non crucial attachments) or pipe because of problems with lack of fusion on the weld bead starts. I either weld these tanks with stick or flux core and I prefer Flux core because it is so much quicker and nearly as good looking of a finished weld as stick welding. The separator has a 3/8" flat bottom and 1/4" shell with two nozzles and re-pads as well. A perfect choice to weld out with FCAW IMO. My problem is I keep getting those damn worm tracks or small grooves on the surface that usually run in line with the bead. These are normally very shallow indications and easily removed by grinding but occasionally they run deeper and sometimes they even have a gas hole or porosity at one end. I have always associated this problem is caused by having the voltage setting to high on constant voltage type machines but I have went through just about every setting with Voltage, wire speed, and gas flow rate and although I might get a decent bead every now and then they all pretty much have the worm tracks. I have also changed the wire to a new spool, change the gas hose, regulator and got a new cylinder of gas. It seams to me that the .045" size runs better than the 1/16" but it still gets the tracks enough that I won't risk using it. After several hours down time fooling with the darn thing I finally gave on fixing it and decided to just stick weld it the other night. Because of having to bid very tight to get the work I do not have a cushion figured in and I can't afford to spend extra time working on equipment or welding with a slower process than possible. If any of you experienced welder types could give me any ideas/suggestions to try and find a remedy for this it would be greatly appreciated.

gun angle w/respect to work?

Hi Pipe welder,

While using a constant potential / voltage power source for GMAW, FCAW, SAW type processes, The Variable parameters like - Amperage, Voltage, Travel speed, Torch angle, Stick out ( electrode extension) are important to get a sound weld metal and also a miter or convex bead profile plus an aesthetic appearance of the bead.

The other fixed parameters being Base metal type & its thickness , Type of wire & its size, Type of gas and its flow rate, position of welding, Forward (push angle) & back word (dragging angle) motion of the torch etc. and they do not differ much during welding.

In GMAW process we also follow a metal transfer modes such as (a) Dip / Short circuit, (b) Globular / Semi short circuit and (c) Spray transfer mode. This works out well for your FCAW process also.

On the Stick out part (distance from the contact tube to the arc measured along the wire) it will be app. 5–10 mm for Dip mode, 10-15 mm for Globular and 15-25 mm for Spray mode. This Stick out is also considered to one of the essential requirement and any adjustments in the distance cause a change in the wire resistance and resulting weld bead profile, apart from your amperage and voltage selection.

Higher stick out beyond a limit contributes to a reduction in weld heat in turn to Lack of Penetration at the root, Lack of side wall Fusion, Porosity, and a thin (width) bead .

Similarly, a lesser Stick out will provide increase in weld heat in turn a deeper Penetration to some extent, higher convexity beyond a limit and " deep groove like appearance" on center of the convexity. This could be one of the reasons in your weld joints shape.

Further, you are using Argon-CO₂ mixture and it also gives more heat to weld bead. We also tend to use a higher amperage for FCAW Process with more travel speed, compared to GMAW , the Stick out could be set more by an additional 5 mm or so in each transfer mode to get a better Weld Bead Profile and without any cavity / worm tracks or small grooves like appearance in the center. In SAW the stick out can go even beyond 40 mm.

Hence, apart from a proper Stick out selection to the Ampere-Voltage selection, Please also synchronize the torch set up depending upon push or pull angle and I am sure you can get rid of the present problems. Regards,

Sridhar.

Thanks for your comment. All of your information is correct and you would think that changing one or a few of those parameters would fix my problem. Unfortunately I have spent hours trying to adjust the many normal variables that you suggest without much luck. I have run through just about every heat setting, gas flow, angle, progression of weld and angle (push or pull) stick-out and so on. I understand the principle of the FCAW and how most of the many variables effect it. This is not a new process for my shop we have used this type welding for 20 years. I just have never had this particular problem so bad that I can't fix it by changing or adjusting some of these normal variables. There is something causing my problem and I just can't put my finger own it or I have a few things that although they may be close to correct are wrong and I haven't found the right combination. I guess I was hoping someone may have had this problem and had a suggestion that I haven't tried or think of something I was missing. I finished the project with SMAW and it did very well although it might of took a few hours longer than FCAW to weld-out. If I am not mistaken FCAW is always in spary arc mode unlike GMAW which can be Short arc, gobular and spray arc according to the heat setting. I try to always push GMAW and usually pull FCAW at about the same angle either way. When I get a chance I will reload the FCAW wire in the feeder and try it all again till I figure it out. I may be trying to hold to tight of stick out and just not really noticed it.

A slip of mind in the late hours. Yes. the FCAW works with spray mode only and similar problem occurred to us when we were using local flux cored wire of 1.20 mm size in multiple run Fillet welding on 40 mm thick plate.

The initial runs went well and during final passes, we had similar problem like what you had and all the parameters were found to be within acceptable limits. But by increasing the stick out by more than 8-10 mm from to original setting and bit change of torch angle in the drag technique, we could overcome the canal like appearance on the face. I do not remember the actual parameters,since it was done years back, but the problem was overcome.

Sridhar.

Thanks for the information Sridhar. The smaller FCAW wire is welding better now but the 1/16' wire is not doing any better. Allowing more stick out is really a way of turning the voltage down or welding "colder". It looks to me like just adjusting the current setting would do the same as allowing more stick out or at least help my problem. It may be that allowing more stick out effects some of the other parameters such as changing the shielding gas coverage or because the wire speed would be a little high if it was set for a normal stick out for an example. I wouldn't be surprised if it turns out that it is a combination of using more stick out and the small changes that this in turn causes to other parameters will fix my problem. I will look into this remedy tonight when I get to my shop.

Thanks or the details and happy to know that one part the problem is solved. For 1.60 mm size(1/16") we keep around 30 mm SO. The results were satisfactory.

As you said the parameters for GMAW,FCAW & SAW type processes are all fixed mostly on trail & error method to get best out of them. if possible you can give the parameters selected for your welding. regards,

Sridhar.

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