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-   -   First time welder with Millermatic 140 (http://www.hotrodders.com/forum/first-time-welder-millermatic-140-a-208307.html)

67Elcamino 11-07-2011 10:53 AM

First time welder with Millermatic 140
 
Hello I have never welded in my life but always been interested in learning and have been reading tons of articles and watching DYI videos online.
I just purchased a nice used Millermatic 140 from a neighbor and he has been giving me sone general tips and advice but I quickly started realizing that he is experience in welding heavier guage steel but not familiar with sheet metal for automotive. At least thats what I noticed from the reading ive done.

Questions;
1 What guage steel was used on pre-1960 american cars?
my neighbor swears it about 14 but Im definite its 16 or smaller Im guessing 18?

2. In order to weld 16 and smaller steel do you need to use gas?
I practicing with .30 wire on a an about 12 guage steel plate w/ no gas and No problem
but when I use .35 wire on 16 guage metal it seems like I barely pull the trigger and instantly burn through and slight warping
Will I need to use gas on metal thinner than 16 guage?
Will using gass run cooler?

Any experience advise for a Newbie is appreciated

cyclopsblown34 11-07-2011 11:16 AM

There might be a chart on the inside of the welder (where the spool of wire is) for heat and wire speed settings. I'm thinking the metal is probably 18 gauge or thinner on anything that old, current vehicles I seem to find lots of 20 gauge. I think you need to turn down the heat to start and practice on good pieces of metal from a hardware store or other source. On sheetmetal, I use the .023 solid wire with gas. Make certain the polarity is right on too.

OneMoreTime 11-07-2011 11:58 AM

I own and operate one of those and use it for about 90% of my fab work..On the older cars a lot of those were 19 gauge metal so we use either 18 or 20 gauge for patch panels and such as the 19 gauge can be difficult to get as it is special order and my supplier tells me that yes he can get it but I have to buy the whole sling or unit of metal and that amounts to a whole lot of money..

So the setup on a Millermatic 140 to weld the thin stuff like 20 gauge is to use the small wire 0.24/0.23 and the gas (c25) and set the unit to autoset for the small wire and then adjust the heat according to the chart for the gauge of metal being welded. The autoset feature sets the wire speed in accordance with the heat selected which saves a newbie the hassle of matching wire speed and heat. Of course one can take the machine off of autoset and manually adjust wire speed if one is so inclined. The 035 wire is most likely flux core which is used on heavier material as it runs a lot hotter than the solid wire..

For practice head on down to the sheet metal shop and have them cut some "coupons" about 2"x6" and practice welding on those until you are comfortable.

Sam

66GMC 11-07-2011 01:11 PM

I am lucky enough to live in a town with an agricultural college, and was able to take an evening welding class for beginners.

It was quite informative, as they started us out with oxy-acetylene torches to demonstrate the concept of "weld puddles" and adding metal to them to produce welds.

We then proceeded thru stick, wire-feed flux, and mig gas welding.

My welds still look like bird-poop :D ...(I'm using a Lincoln 115V flux-core welder at home) but with practice, perhaps they'll improve. My eventual wish is to upgrade to a 180 amp with gas.

67Elcamino 11-07-2011 03:03 PM

Quote:

Originally Posted by OneMoreTime
I own and operate one of those and use it for about 90% of my fab work..On the older cars a lot of those were 19 gauge metal so we use either 18 or 20 gauge for patch panels and such as the 19 gauge can be difficult to get as it is special order and my supplier tells me that yes he can get it but I have to buy the whole sling or unit of metal and that amounts to a whole lot of money..

So the setup on a Millermatic 140 to weld the thin stuff like 20 gauge is to use the small wire 0.24/0.23 and the gas (c25) and set the unit to autoset for the small wire and then adjust the heat according to the chart for the gauge of metal being welded. The autoset feature sets the wire speed in accordance with the heat selected which saves a newbie the hassle of matching wire speed and heat. Of course one can take the machine off of autoset and manually adjust wire speed if one is so inclined. The 035 wire is most likely flux core which is used on heavier material as it runs a lot hotter than the solid wire..

For practice head on down to the sheet metal shop and have them cut some "coupons" about 2"x6" and practice welding on those until you are comfortable.

Sam

Thanks Sam, so are you saying there is not flux cored .23 wire so Im forced to use gas on a .23 wire

silentpoet 11-07-2011 03:49 PM

Quote:

Originally Posted by 67Elcamino
Thanks Sam, so are you saying there is not flux cored .23 wire so Im forced to use gas on a .23 wire

That is correct. Smallest flux core I am aware of is 0.030. If you are very careful you can weld sheet metal with it, but it is very prone to burn through.

OneMoreTime 11-07-2011 04:10 PM

The millermatic 140 comes with the regulator and hose in the box so all you need is the tank..

Sam

oldred 11-07-2011 06:05 PM

You say "forced" to use gas but trust me once you do you will change that to "want" to use gas! :) There simply is no comparison between flux core welding and MIG welding because MIG will be much easier with less spatter, warpage and burn through. A couple of things about MIG however is that it does not like rusty or contaminated metal and does not work worth a darn if there is the slightest breeze so welding outdoors usually does not work very well. Flux core OTOH does not mind a breeze or a fan nearby and it is usually (depending on the wire type) much more tolerant of some surface contamination such as light rust and/or mill scale. Do yourself a big favor get a tank and switch to MIG welding for body panels.

67Elcamino 11-08-2011 01:56 PM

Price?
 
How much would I be looking to spend on a used CO2 tank with regulator to work with my millermatic? Should I buy used or new? what size? to fit on welding Cart and does this stuff go pretty fast?

dallas1 11-08-2011 03:05 PM

i am interested in this as well i am new to welding as-well. I mainly want to weld sheet steel and some square tubing.

jonahb 11-08-2011 05:20 PM

Quote:

Originally Posted by 67Elcamino
How much would I be looking to spend on a used CO2 tank with regulator to work with my millermatic? Should I buy used or new?

Did you check your local welding supply for a lease or on how much to buy a new bottle? Up north where I live I know it is cheaper in the long run to lease a bottle because you don't have to worry about getting the bottle checked out and tested. Just get a bottle of c25 or equivalent and have fun with your new welder.

66GMC 11-08-2011 05:41 PM

From Lincoln's FAQ:

Quote:

Q: Does shielding gas affect the quality of the finished weld?

A: For most mild steel applications, CO2 will provide adequate shielding, but when you must have a flatter bead profile, less spatter or better wetting action, you may want to consider adding 75 to 90% argon to your CO2 shielding gas mix.

Why? Argon is essentially inert to the molten weld metal and therefore will not react with the molten weld metal. When CO2 is mixed with Argon, the reactivity of the gas is reduced and the arc becomes more stable. But, Argon is more expensive. In production welding, selecting the perfect shielding gas can be a science of its own. Attributes such as material thickness, welding position, electrode diameter, surface condition, welding procedures and others can affect results.

Common gas mixes for the home hobbyist and small fabricator would be:

100% CO2 -Lowest price, generally greatest penetration, and higher levels of spatter. Limited to short circuit and globular transfer.

75% Argon - 25% CO2 -Higher price, most commonly used by home hobbyist and light fabricator, lower levels of spatter and flatter weld bead than 100% CO2. Limited to short circuit and globular transfer.

85% Argon - 15% CO2-Higher price, most commonly used by fabricators, with a good combination of lower spatter levels and excellent penetration for heavier plate applications and with steels that have more mill scale. Can be used in short circuit, globular, pulse and spray transfer.

90% Argon - 10% CO2- Higher price, most commonly used by fabricators, with a good combination of lower spatter levels and good penetration for a wide variety of steel plate applications. Can be used in short circuit, globular, pulse and spray transfer.
TRY C-25 SHIELDING GAS (75% Argon, 25% CO2 )

67Elcamino 11-08-2011 05:46 PM

Can I buy an empty used bottle of any sort and fill with C-25? or does each bottle have to be unique to the mix?

Where do you purchase these mixes? Im in So California

timothale 11-08-2011 06:26 PM

martin sr info
 
Martin Sr has written a very good guide to mig welding. I printed it a couple years ago and filed with my welding manual then gave to my son and told him to read up, improve his welds. I don't have the link but mabe he or someone else can link you up to it.

mmopar0521 11-08-2011 07:33 PM

I bought a bottle my first time at Airgas (size 40 bottle), and each time I go for a fill they trade it out for another rather than filling the one I return. Believe the fill is around $20. The bottle the first time is around $100. I ended up buying a spare after the first time I ran a bottle out after a long couple of days welding on a weekend, and couldn't get a refill.


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