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Old 04-10-2006, 11:00 AM
SCHOONER SCHOONER is offline
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Question 2 Different Proper Gas Mixes

Hi

I'm new to mig welding, but I did weld Elec. & Tig ~ BUT NOT 'MIG'

2 QUESTIONS PLEASE:

I'll be Mig welding (but not till I hear from you guys) 16 to 20 gauge sheet metal. Its car sheet metal don't really know the exact gauge. I'm sure you pro's out there will be kind enough to straighten me out on the gauge.

Question# 1 What is the proper gas mix for welding that car sheet metal

FINAL QUESTION PLEASE:

I'll be weld on the frame of the car (much heavier metal, again don't know the guage.)
I'll be using Flux-Core wire of course. What would be the setting for that kind of welding on the frame

I'm buying a Millermatic 135 unless you guys think I need something smaller that will still done the job

I will not be welding everyday, this is for my classic Mustang. So after I weld the sheet metal and part of the frame, that will be it for awhile on welding.
Till my next project of course.

THANK YOU ALL
GOD BLESS YOU AND YOUR FAMILIES.

Schooner
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  #2  
Old 04-10-2006, 11:56 AM
rasommer2002 rasommer2002 is offline
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Quote:
Originally Posted by SCHOONER
Hi

I'm new to mig welding, but I did weld Elec. & Tig ~ BUT NOT 'MIG'

2 QUESTIONS PLEASE:

I'll be Mig welding (but not till I hear from you guys) 16 to 20 gauge sheet metal. Its car sheet metal don't really know the exact gauge. I'm sure you pro's out there will be kind enough to straighten me out on the gauge.

Question# 1 What is the proper gas mix for welding that car sheet metal

FINAL QUESTION PLEASE:

I'll be weld on the frame of the car (much heavier metal, again don't know the guage.)
I'll be using Flux-Core wire of course. What would be the setting for that kind of welding on the frame

I'm buying a Millermatic 135 unless you guys think I need something smaller that will still done the job

I will not be welding everyday, this is for my classic Mustang. So after I weld the sheet metal and part of the frame, that will be it for awhile on welding.
Till my next project of course.

THANK YOU ALL
GOD BLESS YOU AND YOUR FAMILIES.

Schooner
I'm not a pro -- so please take it for what it's worth.

First off -- gas mix

I may be confused about the wording in your post but when welding flux core wire you don't need gas -- that's the idea behind flux core -- no gas.

As far as the mix is concerned, that usually comes down to a personal prefernce as well as the type of mig welder you have (depending on make and model, they all behave differently)

I've welded with pure C02 and it worked very well with a 3-phase industrial machine, but presented way too much spatter on my hobby style HF Chicago Electric Dual-Mig 185. So I asked around and experimented.

I get best results with a 50/50 mix of CO2/Argon when working on rusted sub-frames, and I get excellent results with a 25/75 mix of CO2/Argon when welding clean sheetmetal. Others still prefer pure CO2 or flux core for frames -- mainly because of the cost. In the end it comes down to technique, experience and some extensive experimentation with the welder you have.

I don't know too much about the Millermatic 135 -- but for welding up frames on older vehicles, it may be a bit underpowered --espececially when using flux core wire.

Hang in there -- one of the other members will have some experience with the Millermatic 135.


Ray
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  #3  
Old 04-10-2006, 12:06 PM
JT Metalworks's Avatar
JT Metalworks JT Metalworks is offline
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Sheet metal is one thing, frames are another. If your panel falls off at 70mph, you buy a new one. If your sub-frame comes apart, you might not make it to the store ever again. Or worse, you injure or kill someone else instead of yourself.

The machine is too small to do structural work without a whole lot of arc time (and even then, no one in their right mind would buy one that small to do that type of work). Mig welding is much more than just squirting metal on a joint. Since you say you have stick and tig experience, how much of that do you actually have? Getting a 175A (or better) class machine would be a much better choice. It's just a chore to get enough heat out of a 135 to do anything which needs to hold in a roadworthy way. It can be done; but it's far from "point and shoot" one or two weekends a year.
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Old 04-10-2006, 02:20 PM
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Shade Tree Welder Shade Tree Welder is offline
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Quote:
Originally Posted by JT Metalworks
Sheet metal is one thing, frames are another. If your panel falls off at 70mph, you buy a new one. If your sub-frame comes apart, you might not make it to the store ever again. Or worse, you injure or kill someone else instead of yourself.

The machine is too small to do structural work without a whole lot of arc time (and even then, no one in their right mind would buy one that small to do that type of work). Mig welding is much more than just squirting metal on a joint. Since you say you have stick and tig experience, how much of that do you actually have? Getting a 175A (or better) class machine would be a much better choice. It's just a chore to get enough heat out of a 135 to do anything which needs to hold in a roadworthy way. It can be done; but it's far from "point and shoot" one or two weekends a year.
And to add on the frame where and how you design you weld joint is more important than the machine you are welding them with. I suggest you get an experienced welder to perform that welding for you.

As for the mix run 75/25, for the little you will be welding the cost will be minimal. With the gasless fluxcore wire gas is not needed. But the polarity of the gun needs to be reversed versus solid wire.
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Old 04-11-2006, 12:04 AM
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Schooner:
As mentioned by others above, the 135 will be good for the body panels but weak on the frame. Spend the money for a more powerful machine IF you are capable of safely welding your frame! It may be something best left to a bodyshop. The 175 is a good choice if you have 220v power.

Use 75/25 Ar/CO2 gas--it is commonly available and works better and cleaner at low power. Why would you want to use fluxcore when gas and bare wire will work just as good if not better? The cost is less, too. Welding a combine in a windy cornfield with fluxcore or stick is a little different than a car frame in a garage.

Where are you from? With a handle like Schooner, I'll assume your are near the ocean and have salt rust/rot damage? Post some pictures for us to see. I'm sure you will get plenty of sound advice from the many wizards in this forum. Welding a floor/seat stiffener is a little different than a leaf spring perch or other vital suspension component... What have you?
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  #6  
Old 04-11-2006, 12:42 AM
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Welcome aboard, Schooner.
Before I jump on the "git a bigger mig" bandwagon, let's get this location thing out of the way; standard blurb follows:

We try to maintain a little custom around here of posting our locations in our user profiles; that way it appears in every post or reply that you make. If you look at the upper right hand corner of this window you will see that I am located in Lubbock,Texas. We have found this to be especially helpful because so many of our threads wind up in discussions of where to find parts, materials or some activity where local conditions are a factor. You will probably be surprised how often this is true here. Besides that, we're just naturally nosy & like to know where everyone's coming from. Posting it one time in a reply is not the same as doing it automatically in every reply.

If you would please, look in the upper left area of this page at the blue banner with white lettering, click on "User CP" to open your control panel; click "edit profile"and scroll down to the location line & fill it in. City & state / province is sufficient. Then be sure to scroll on down to the bottom of the page & click "save changes" & you're done. We will appreciate it.


Now in your case, once we know where you are, there just might be another member in your locale who can advise you or maybe knows of a deal on a welder and who might even help you get lined out.

As to your intended choice of welding machines I will pass along to you what has been taught to me; I suggest you buy as much machine as your budget can handle. You can turn a strong one down; you cannot turn a little one up - very much. The 135 would be fine for your sheet metal and up to about 1/8th inch or even 3/16ths so long as you're not doing critical welds. Auto frames are critical. You haven't really given us much information about the level of your experience but if you are relatively new to welding, then I suggest you be very careful about undertaking any frame modifications on the Mustang. In any event, I recommend you buy at least a 175 class machine, 210 if you can. One more time: I have never met an unhappy Millermatic 210 owner.

Flux core is fine for outdoor welding and for when you're trying to squeeze maximum penetration from a 135, but on body panels, you'll get lots more spatter to clean off. Using C25 gas & bare wire as mccutter & others have suggested will save you lots of clean up work later on. You just get smoother beads. As to the cost, fluxcore wire costs a great deal more than gas shielded wire so the end cost (including shielding gas) is pretty much a break even deal.
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Old 04-11-2006, 01:07 AM
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Flux core and MIG are NOT a break-even situation for cost. MIG is far cheaper. I get at least 60# of wire on a 80cf tank of c25.

So lets calculate this out for reality's sake here. (prices off cyberweld's current list)

Flux core wire, 10# spool: $49.23 x6 = $295.38

*However, this is less than 60# of solid wire worth of welds. So this isn't even accurate and the volume of wire consumed for the same amount of welds would be substantially more using flux core.

MIG costs -

80cf bottle: $170

HB28 MIG wire: $20.36 x6 = $122.16

80cf C25 fill = $22 *(this is my price, cyberweld doesn't ship full cylinders)

Grand total: $314.16

Cost of 7th spool of wire with MIG: $20.36

Cost of 7th spool of wire with Flux core: $49.68

Which is cheaper now?

You also have a bottle which has a tangible resale value. With flux core, you have tan dust on places you didn't know existed.
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  #8  
Old 04-11-2006, 01:19 AM
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ANd to throw a monke into your barrel,
theres two kinds of flux cored wire..
selfshielded,
and gas shielded...which is been around longer.
So yes some flux does need gas.
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  #9  
Old 04-11-2006, 01:34 AM
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Yeah, but that's not what this guy is going after.

I'm sure some of the dual shield wires would work great on that frame. Getting enough heat out of the 135 to make them sizzle might not work so well.

Someone else said something that I think makes a lot of sense about machine size: "If you can't burn through your work, your machine isn't big enough."
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Old 04-11-2006, 01:38 AM
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Waal, now the point I was trying to make is that flux core wire is not really a cost saver to the hobbiest welder. It kinda looks like it going in but that shouldn't really be a consideration.
At this stage of the process & based on what he said, I doubt that Schooner is anticipating buying 7 rolls of wire anytime soon. Me neither; I'd be worrying about using it up before it rusted.
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