I've been getting a lot of suggestions and input lately from various "Welding Process Specialists" concerning the welding processes we currently use in our fabrication shop. You've probably met a few of them yourselves, it seems every major supplier of gas and consumables has a whole team of them these days. What's disconcerting to me is that they don't usually have the same suggestions, so are they merely suggesting we use whatever they can make the most money off of at the moment, or what? I would greatly value the opinions of you welding geniuses that regularly contribute to this forum, and I'm sure others here would learn much as well. Here's our situation:
--We manufacture certain ropeway transportation devices that are normally found in a snowy environment, on a mountain...
--These devices are almost entirely made from A36 or A572 carbon steel, and 99% of the time are galvanized after fabrication.
--Although very complex, most of our design allows for fillet welds, with occasional PJP and CJP joint configurations.
--We are currently welding with FCAW-G (Dual-Shield), .052, and 100% CO2 gas.
--We use GMAW-S on thinner parts and sheet metal applications, .035, and 75 Ar/25 CO2 gas.
--All welding is performed in the flat or horizontal position, our large pipe structures are welded on rollers in the flat position.
So far I've been advised to replace the FCAW-G with GMAW in spray mode, or to replace the FCAW-G with MCAW-G, and nobody has yet advised us to keep our current process. So it seems that good old Dual Shield is becoming archaic, or are they just wanting to make money somehow? Is Dual Shield dying?
Please keep in mind that I recently started with this company (two years ago now) and inherited what was already in place, so our current processes are not my doing. We have no real problems with things as they are at the moment (in fact our welders are turning very high quality welds with almost no re-work required after inspection), it's just that our Management team is always wanting to improve things and is not afraid to try something new, especially if it will increase productivity and lower costs (as promised by our "Welding Process Specialists"). What say you?
You can't beat a process that has proven itself time after time. Stay with FCAW.
Al
I'm guessing the profit margin is substantially higher for the wire and gas mixes for MCAW.
FCAW with 100% CO2. It just don't get any cheaper than that. OK, NR 211 is the ultimate in cheap and fast.
It's always ALL ABOUT THE MONEY.
Hard to say without knowing any of the costs. What does shop time cost, what's the differential on solid and FCAW wire, deposition rate increase, speed increase (If any). Some of that stuff might make sense, some may not.
Remember, if we stayed what what is proven to work, you would be forge welding your parts
I would ask these salesmen(women?) to provide you with a cost benefit analysis that will spell out to you how much changing from your present process to the new equipment and process will cost and what the payback will be.
After they come up with this ask them to provide you with 4 or 5 companies that have made the recommended changes. Follow up with these companies to verify the numbers. In addition check with your competitors and see what they are doing. If you can find some who have made similar changes try to get hard cost on what they think and know how the changes profited their bottom line.
If you have welding equipment that is 10 years or more older, you may want to stay with the same process you have with new equipment.
Are you working with a WPS if so you will have to go through the process of certifying your welders all over. Check the price of doing that and let the Management team make there on decision.
M.G.
FCAW is fine, and CO2 is cheap, but usually 85% of every dollar spent for true welding costs is labor.
With FCAW and CO2, you're probably spending a fair amount of time cleaning flux and spatter from welds.
Also, OSHA has greatly reduced the permissible exposure limit to welding fume, which FCAW is a high generator.
MCAW is great as it burns well and doesn't leave behind slag, but there's a trade off to consider when you consider higher consumable cost and fume generation.
GMAW solid wire with and 90/10 argon/CO2 gas mix is pretty cheap, has little clean up, and is the lowest fume generator.
GMAW spray is limited to flat and horz position, but that doesn't seem to be a problem.
The advances in GMAW pulsing technology allow you to tailor fit waveforms for joint conditions, to maximize quality and deposition.
Pulse may however require the purchase of a different power source, which is not always a good thing.
There's a lot of common sense in the term "If it ain't broke, don't fix it."
You can change processes to acheive cost reductions by maximizing efficiency, but Welders by nature are hard headed and resistant to change, so it doesn't always go to smoothly.
Tim
I wish I could somehow promote this post. In every cost analysis I've done labour is 80-90% of welding costs. Using "cheap" CO2 doesn't save you when you're paying a guy to grind spatter off every piece. using "expensive" 85/15 can save money if it just makes you weld 1-2IPM faster
Metarinka ,I have seen some good looking welds with FCAW using CO2 and if you have everything dial in you want have all that grinding. I have used an air blower and taken the flux off with it.
M.G.
I agree with Milt. I have run a lot of weld with FCAW-G and have very little problems with spatter or tight slag. Now, FCAW-S is often a different story but it depends upon many variables.
Have a Great Day, Brent
oh yes, In my head I was referring to GMAW with CO2 vs 85/15. FCAW is a different beast and can run quite nice under 100% CO2.
There are some excellent responses and forgive me if I duplicate some of the information. Here are some of my thoughts.
1) Not having to remove slag is a considerable boost in production factor only if the welders who you have are interested in such things.
2) The deposition efficiency in solid wire is often times much greater than that with FCAW. Especially when using the spray transfer mode.
3) The ability to change from thick to sheetmetal thicknesses is much greater for solid wire than for flux cored wire (i speak of 71t1 vs er70s-x). A change of gas is often the biggest task.
4) During high deposition rate welds with FCAW it is very difficult to notice porosity that may be forming as you weld. With GMAW it has been my experience that it is very noticeable when it occurs. Of course if all is done correctly, this is not an issue.
5) FCAW seems to be a little more tolerant of oily or contaminated base metal or slight drafts in the welding area. But that should not be a problem if everything is properly prepared and protected from drafts.
6) The deposition rates in the vertical, overheard, or horizontal position that can be achieved with GMAW any transfer mode cannot get anywhere close to what can be achieved with FCAW. I love me some 71t1 welding on stuff that requires alot of quality weeks metal and the conditions permit. (Got a Lincoln active8 wire feeder at work and use it whenever possible). However change the material thickness to gauge thickness and that is not the case.
And I am sure there are other things to consider.
One of the key things in my opinion has been touched upon above. The willingness for the welders to change. It's very easy to make something appear that it doesn't work well. I get a few odd looks when I break out the arc gouger or worse the plasma cutter when the good ole 2400 psi oxygen cylinder next to 300 ft3 off acetylene would do the same thing.
Again, this is much my opinion based upon my limited experience. A good welder with a bad process can often spank a bad welder with a good process.
Have a great day.
Gerald Austin
In our current economy you will find many vendors attempting to get you to think outside the normal paradigm box with a bent in their direction in order to sell both equipment and supplies. Not to mention sending support people in for a while who need to justify their job by giving you advice and assistance in training the welders in the new process that few of your people may know how to use.
And, beyond that will be the already mentioned extra costs of new WPS's, Welder Qualification, and other factors lowering the promised profits for a considerable amount of time.
The cost payback of replacing any equipment that is already in place and still functioning is very minimal for several years, regardless of what the pencil pushers say. There are of course exceptions when the company has the right resources to throw at a new job that will in and of itself pay for all the change that will be involved in new equipment, additional training, qualification, consumable expenses, and other factors. But for the average shop, only replace it when it must be replaced. Then, you may want to do a little experimenting with a new process to see if it is cost effective.
My little shop has FCAW-G & -S, GMAW & -S, SMAW, and GTAW constantly available. The machine in use will depend upon the job being done. I have my personal preferences for various applications and plan my jobs accordingly.
Have a Great Day, Brent
It's hard to say without knowing details. I've done a lot of cost analysis. Labor is 80-90% of welding costs. It's hard to beat FCAW on deposition rate if you are welding thick components, what's also important for a lot of shops is travel rate, and with that it's hard to beat GMAW-S or FCAW. In all honesty things like gas choice often end up only being the about 1-2 pennies a foot difference in cost savings, if you can pump your arc-on time or travel rate by even 1-2 IPM you'll far out pace the costs of the consumable.
You also have to consider secondary ops, GMAW-S with 85-15 or 90-10 Ar/CO2 will produce a lot less spatter than Dual shield with CO2. If you are paying someone to grind spatter before powder coat or paint, you can probably save money on consumables and labor of grinding ops.
If you search for my user name, some time ago I posted a welding cost analysis spreadsheet I had made for my college internship. all you need is a stop watch to figure out your travel rate and you can get a good handle on your weld costs. A lot of places think they save money using 100% CO2 on GMAW only to realize that GMAW-S with 85/15 will go about 3-4 IPM faster and save about 20%-30% depending on labor rate. Harder when comparing two different processes, but it's cheap enough to trial.
Good input Metarinka, and thanks for the spreadsheets.
"My last project is tying it all together so that you can input the weld size and get the strength and then figure out how much metal and how long it would take to weld." - Metarinka 2008
Did you ever finish tying it together?
Tyrone
wow, refreshing my memory. I believe I actually had a beta application up and running at one point. It's okay for short straight lengths but at some point It becomes a discrete weld stress analysis program and the complexity goes through the roof. once I was out of college I stopped doing weld stress analysis for my job so I think i let the project die.
I have a BASIC program I wrote many years ago that may be of interest. It may not run on newer systems. But you can try it.
If anyone is interested I will send it to them or upload it here. Nothing fancy. The user needs to know all of the input variables.
I can't thank you guys (and gals) enough for your input, this forum is a great resource. I would like to change the direction of this thread just a little bit. If we throw the cost of consumables, productivity rates, and labor costs out the window, and just focus on the overall quality of the weld itself, what are your thoughts concerning the different welding processes available for welding structural steel? Do you feel that some hold up better over the years than others? What about when cyclic stresses are involved? Susceptibility to cracking? Differences in penetration? What experiences have you had?
choice of welding process depends on various factors, so choice change as the requirements changes
few weld requirements are
joint type and design
welding position available
qty of work
accessibility of weld
purpose of welding
to name a few, my preferred welding is SMAW, due to reason that diffrent types of material can be welded
is that your only reason? I ask this because the same could be said of some other processes also.
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