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John_Wayne
03-12-2010, 11:07 AM
So I've been MIG welding without gas for a few years now, and I'm presently taking a course to become a certified welder. I've also been welding for myself and a few friends, and have never considered charging them for my labor or materials, as they are buddies of mine and I just think that would be wrong. I do however, have a new side job that will require me welding for someone I met on another forum and I need to calculate how much I should charge him only for the materials. I calculated that I weld about 12-14 Inches per Minute to make sure that the welds are plenty strong, and use up 156" per minute of .035" inner-shield wire. Each spool I buy is a 2lb spool. My question was, do any of you know the approximate length of wire in a 2lb spool? And if not, can you guys give me an idea of how much I should be charging him for the materials?

Thanks, :)

DSW
03-12-2010, 11:32 AM
Keep one thing in mind. As soon as you charge someone to do work you become liable. Your statement


I calculated that I weld about 12-14 Inches per Minute to make sure that the welds are plenty strong, and use up 156" per minute of .035" inner-shield wire.

Doesn't give me a warm fuzzy feeling about your skills or the project. It sounds like this may be something that you might have a concern over strength of the weld. Should there ever be a problem, your @ss is hanging in the breeze. Don't think you can just hide behind cash and think that theres no way to find you. The lawyers will tear every thing apart looking for someone to blame and get money from nowdays. Your partner will dime you out in a heartbeat to cut his losses. I'm guessing this is some sort of 4x4 project, hopefully bumpers or sliders and not structural components for which FC wire is a poor choice usually.

With 2lb spools you could always weigh some scrap wire to get some sort of idea how many inches to say an ounce on a postal scale if needed. I think I saw a chart in Lincoln's "Bible" that helped figure wire use for estimating. 2lb spools are a poor choice for production unless using a spoolgun. You usually pay more per pound that you will with larger spools. When I usually quote small jobs, I either just figure in a spool of wire, or write it off from another job, depending on the quantity of weld. With out some idea what you are doing and all it's a tough call. Most likely figured in inches it will be less than a penny or something. I usually don't buy FC wire. I think the last time I looked a 11lb roll was $50 or something. I'd easily bet I could run 50 foot of small weld no problem from that, so that would be $1/foot on the super high side. Per inch thats like 8.3 cents an inch. I know I ran all the welds on my 9' plow rebuild and didn't make a real dent in my 10lb spool of solid .030. I had to have over 25 linear feet of weld there.

weldinglifer
03-12-2010, 11:54 AM
There should be approximately 8000 inches of 0.035" dia. flux core wire on a 2 lb. spool.

John_Wayne
03-12-2010, 01:55 PM
Doesn't give me a warm fuzzy feeling about your skills or the project. It sounds like this may be something that you might have a concern over strength of the weld. Should there ever be a problem, your @ss is hanging in the breeze. Don't think you can just hide behind cash and think that theres no way to find you. The lawyers will tear every thing apart looking for someone to blame and get money from nowdays. Your partner will dime you out in a heartbeat to cut his losses.

I have no concern what-so-ever over the strength of my welds, in fact I would probably trust my welds with everything I have. Never has one cracked or not held properly. I do understand what you mean by "my @ss is hanging in the breeze" but I would not put myself in a position where I could loose everything I have over a weld giving out. I would make it very clear, on paper, that I am not liable for anything that happens.

You also mentioned "I'm guessing this is some sort of 4x4 project, hopefully bumpers or sliders and not structural components for which FC wire is a poor choice usually". I have made both bumpers and sliders for my Jeep, and have pulled out an old F-350 with D-Rings that I welded onto the bumper, which was made from 1/4" steel. I know its not as impressive as towing out a dump truck or something a bit heaver, but the welds held up just fine. I have also welded many suspension components to the frame of my Jeep, and never had any issues. Believe me, if I could get a hold of some gas and maybe buy a stronger welding machine, by all means I would... But right now I'm very content with mine. :)






There should be approximately 8000 inches of 0.035" dia. flux core wire on a 2 lb. spool.

Thank you very much, that answers my question. :D




Btw, what is the average Inches Per Minute in Wire-Feed Welding?

MoonRise
03-12-2010, 02:13 PM
Wellll, let's see now ...

There is no such thing as "MIG welding without gas". MIG, by definition and by what's in the acronym itself Metal Inert Gas aka MIG, uses a shielding gas as part of the welding process. The more correct terminology though is GMAW for Gas Metal Arc Welding.

There -is- a wire-feed welding technology that doesn't use shielding gas though. But that is called FCAW-S or just flux-core.

Both GMAW and FCAW are wire-feed welding processses, and they can often use the same machines (if the machine can be adjusted appropriately for the desired process). But they are not exactly the same thing and may not produce -exactly- the same end result. Because the filler wire electrode and the process influence the resultant weld.

With proper procedures and proper electrode selection, both GMAW and FCAW -can- produce good quality welds. But they are not necessarily always directly interchangable.

Next, as DSW pointed out, as soon as you get paid for the task, you are IT liability-wise.

And as pointed out, the little 4 inch spools of welding wire electrode are typically the most expensive on a per pound basis. Even moving to the 10-12 pound 8 inch diameter spools lowers the per pound price drastically.

And the little 4 inch spools of wire are typically 2 pounds for SOLID GMAW wire and 1 pound for FCAW wire.

As to how many inches of wire are on a spool, for FCAW wires that will vary a bit compared to a solid wire because of the different flux powders used by the different makers and for the different products. But as mentioned, for an 0.035 diameter FCAW wire, there are about 4000 inches of wire per pound.

As to how much wire will be used for a task, you can also just figure out how much resultant weld you will apply and then multiply by the process efficiency to figure out how much wire would be needed to apply that much weld. For a 'typical' small diameter FCAW wire, the process efficiency is about 85%. That means that for each pound of wire you use, you got a resultant of 0.85 pounds of actual weld. The other 15% of what you started with ended up as slag or spatter.

Metarinka
03-12-2010, 02:55 PM
Moonrise gave some useful information. I developed a spread sheet about two years ago to help me calculate welding costs

http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=105308

usually the formula for figuring out consumables use is: calculating your deposition rate, then multiplying it by the amount of arc-on time needed to fill the joints. For flux core the deposition efficiency is about 86% off the top of my head.

For solid wire it's easy to multiply the cross sectional area (area of wire) by the density of steel to get a good approximation of inches of wire per pound and so forth. A little harder with flux core as it's tubular.
you can also just cut a few bits and put them on an accurate gram scale, or call the manufacturer they would be able to tell you that.

I also add in a bit of cost for where items like nozzles and contact tips. usually replace them every so many arc-hours.

that same spread sheet can also help calculate welding time. 12-14 minutes is on the high side of manual welding FYI, not saying you're not hitting that but on weave beads that's getting unrealistic.

Stick-man
03-12-2010, 07:16 PM
Info taken from McKay Full Line Catalog.

Inches per lb. of wire.

.024" = 7,788
.030" = 4,960
.035" = 3,650
.045" = 2,210