my original argon valve was bent up and leaked, so I ordered a new one. it had again, different sized threads, jeez.

so I went to ace ( r towel advice) and went with barbed fitting at both ends since the new argon valve came with a 1/4 barb already.

question - when you are done welding and want to purge the lines of argon, after shutting the valve on the tank, do you have to waste wire or is there a way to purge without wasting wire?

also, I expected the bead to stay at 15 psi when i turned the brass valve open, but it only rises to 15 psi or what ever I set it at, when I pull the red trigger on the mig - is this normal?

also - I prepped some of my old real estate signs for practice : )

jim

I purge my tank the same way. I turn off the tank valve and press the trigger till the tank gauge says zero and then watch as the regulator gauge also says zero. If you don't want to waste too much wire when doing this you can turn the wire speed way down and not so much will come through. I then (try to) remember to turn the regulator valve handle to the left till it is loose and relaxes pressure on the valve. I'm just a welding hobbyist but I will be staying at the Holliday inn in Flagstaff on the way to the RCC. Maybe we'll hear from the experts here. Scotty?

Never heard of purging the line.

I only do it to bring both gauges to zero. Relaxes the pressure in the gauges and I'm told they last longer. And I have cheap gauges.

maybe I just like Asian chicks - but see the last few minutes of this video

link

[i][/i]

You mention Asian chicks, then provide a link that doesn't work. That's just mean!

Asian chick link is fixed

The only reason to "purge" the lines is to relieve pressure on the regulator diaphragm.

Lift up on the wheel hold-down lever in the wire feeder

The wheels will turn but not feed wire.
(wheels will be HOT while doing this)

Stu

Asian chick and UC Irvine.

my first 4 welds : )

I was turning wrong dials a few times but 4th row is better than first : )

shown is panel front, panel rear where I did not remove paint, and rear of 4th weld upclose, and first again back lighted.

seems that having a copper back plate has got to help in most cases?

this is gonna take some serious practice and dialing in.

I knew we would get a definitive answer eventually. Thanks Chris.

actually, I only waste about 5-6 inches of wire when I watch the psi gage drop to 0. I thought it was way more.

Copper back plate helps! Work towards moving the puddle of molten metal in the direction your welding. Experiment with both pushing and pulling the puddle, you'll probably find you're better at doing one over the other, although the orientation of what you are welding will often dictate which method you'll use.

i'm not sure I was ever moving a puddle, at all.

I will work on creating a puddle. to move

my mig has .030 wire in it - i figured I would leave it in for practice - and i think the panel are maybe 20gage +-.

is it night and day between using .023 and .030 ????

thanks

I've never used anything other than .023 but I only weld 1/8 inch or less. I was taught that pulling the puddle makes for a deeper weld that pushing.

pushing is usually better

I used a cut off wheel to cut the slices - so working with this gap - even though it was not much - was certainly more than welding a butted joint - and certainly, I assume, makes it much harder to create a puddle.

for my next trick - I will try some tight butts next.

That's a great way to practice. I never thought to do it like that. Great idea.

Maybe do 15-20 though...instead of 4. ;-)

You'll get there. I still have all my 'practice pieces' from 2004 when I bought my welder.

I never turn off the valve on my tank. My gauge is 30 years old and never had an issue. I have barbed fitting and clamps. Never had a leak. My tank lasts years.

Start on thicker metal, and start understanding what you're trying to get the feel for. You'll start to understand "the feel" then move towards thinner metal.

I'm a beginner as well, have some sheet metal practice welds that look similar, but don't worry about wasting the wire, get the big spools and practice away. Someone else may want to chime in but gass at 15 seems a little light, I think my welder likes 20.

all good and helpful comments - thanks guys!

The difference might be, that my gauges and valves were made in Shanghai.

Pushing is usually better..
An old fart used to tell us young fellas his philosophy on mig..

"What would you rather do?? Push your wire or pull it??"
Corny,but true.
Practicing on uncut material is good. Laying beads, over and over. Then work on lap joints.. Tees. Outside corners etc.

.023 for 24 gauge

.030 for 12 gauge (1/8")

YMMV, depending on your experience level

Trying to bridge a gap with the wrong size wire right out of the gate will only frustrate the hell out of you. To do sheet metal right with minimal warpage, you need to weld a series of SHORT 1/4" length beads every 6 inches, then go back and do the same every 3 inches, then every 1-1/2 inches, etc. until the butt weld is complete.

Keep the .030 in and get some 1/8" raw steel plate and practice running beads as speed metal army stated above.

YEARS AGO, as a young welder just starting out, I didn't have access to a MIG. SO I got real good at welding sheet metal with a stick welder. How'd I do it? LOTS of practice.

guys - thank you all

think I better get me some- easy grind - .023 wire

scottyb wrote "Thermodynamics = firepower // ESAB = spoolarc"

no sense practicing on thicknesses I have no immediate intention to be working with

http://www.914world.com/bbs2/index.php?sho...p;hl=easy+Grind

jim

Jim, easygrind is about 4x's what regular wire is and you won't need that until you start your exposed body work. FWIW, I do most all my welding in the garage where the wind doesn't blow and 10psi of mix is usually enough. If there is a breeze coming thru I'll boost it up to about 15psi. The copper spoon is the trick and you will burn thru a few (thinking you've managed to weld copper to steel ) in the beginning. I don't know how our resident body experts keep a spoon in place but I use cheap magnets when my one and only pair of large C clamp pliers won't fit. One more beginner tip; clear the area of flammable materials. In the past 9 mo's I have ignited 3 shop towels right next to my head when welding. PS, get some .023". You'll need some and a small spool is only about $7.

On this sheet metal I usually don't run a bead at all. Just a series of well placed 'spots'. A real welder would probably lecture me on proper technique, but it's worked well for me.

You are starting off by trying to do one of the hardest tasks (bridging a 1/16" gap). I think your learning curve will end up faster if you start with just a bead.

I suggest:
1) Run a straight bead 4-6" across your practice piece. Try push and pull, flat, uphill and downhill. When you can make a nice bead, move on.

2) Lap joint - cut a piece off your practice piece and scab it over part of the remainder. You can also drill some holes in the cut off piece and practice plug welds.

3) Butt joint - get two piece with nice, tight fit-up.

4) When you get comfortable with the above, work on filling a gap.

Hope this helps.

P.S. I would grind more (probably all) paint off your workpiece.

great advice

I think I was expecting to hear much of what you guys are saying, from reading older threads on mig welding.

I will keep showing my practice welds here for comment.

off to harbor freight, I need a welding shirt, some nozzle grease, some welding vice grips, and I guess some regular .023 wire for now.

just got back from a visit to Milton de dogfish head beer factory. lots of stainless piping, welded up really nice. i'll post some pics later (pics posted). forgot to mention the sausages and sample beer, yumm-O

thanks again!
jim

got it - beads are for butts

Jim, do a Youtube search for "Restolad" as he has a tutorial on how to weld thin sheet metal. Actually all his videos are very educational and he shows how to use the copper backing plate to keep from blowing holes in thin metal.

100%

This thread makes me want to go buy a welder so I can try all the stuff I just read

I am in the process of backdating my bumpers. On the back I drilled out the spotwelds with a relatively flat-headed bit, thinking that I wouldn't go all the way through. Wrong x 8.

With probably about 30 minutes more experience than you, Jim, I started to fill the holes. The first 4 on the passenger side took me an hour and a half. The other side took me 20 minutes.

Practice does pay, and I am going to get some sheet metal this weekend and take advantage of all the advice above.

Jim,

I prefer .30 wire personally for most bodywork.

You should be using as little gas as required to keep the weld from bubbling/sputtering. I use about 15, take it down to 10 in a super controlled environment and up to 30 in windy weather.

You need to practice running lines before you start bridging gaps like the 3/32nds gap you were working on. I bridge a gap like that with either a lot of wire speed and VERY quickly(This takes a lot of talent... and practice) or with tacks.

Run lines till they are solid beads that have great heat penetration. Do 10 lines 4" long, number them and post up a pic. We will help you analyze and modify your technique.

Also I've never purged. I have a semi leaky system after my good welder setup got stolen and I had to build one off of a budget Lincoln 100, but I never purge. I do however shut off the valve after every short use.

I ordered an eastwood metal gauge so I can know for sure what thickness my practice metal is. $12 shipped on ebay. should be a big help.

andyrew, I will do that bead running thing and post pics asap.

bigken

I too am backdating bumpers and removing all engine bay tin, and have been using this spot weld tool - only a very few drill thrus with it.

Here's some welding stuff. Copper strip use on page 3.

http://www.914world.com/bbs2/index.php?sho...107923&st=0

And here is some info on splitting spot welds. Lots of ways to get the end result. This is just one I use.

http://www.914world.com/bbs2/index.php?sho...=212470&hl=

I read this post originally and thought that your grinding method does indeed make sense. I shall try that approach next time. Good tip!

per andyrew's request - here are some samples at different settings.

front and back of panel - thickness I am not certain of, could be 20 gage??

wire is 030

all done push style from bottom to top - but I barely see the molten puddle, I see the bright molten area as the sparks are flying but I don't linger there enough that I can say I am pushing a puddle at all.

oh, and in between the top and bottom bead, I layed 2-3 tacks

and for some reason, I keep reaching for the bottom knob - less today - for amps vs wire speed, I need to take my time and really look when I make setting changes.

That's a great way to learn what the settings do.

To be honest 2.5b looks like the best setting for that metal. Its definitely about 20 ga if it reacts like that.

Your optimum weld is one where you jave your bead up top but just a tiny bit of metal coming on the back side. You see that with 2.5b

3c looks more like its putting a lot of metal down. There is almost as much weld above the metal ad below it. This will cause metal warpage as you see a lot of heat being thrown around.

Now do 10 lines of 2.5b and 10 of 3c. And post the pic. We need to work on your form.
Be aware you can weld with any of these settings and lots of times you will as your metal is never the perfect thickness while working on cars.. sometimes its geound down or really thin, ext.

After you did the 20 lines cut the signs in half and lay them over each other with about 1" of overlap. You'll be doing a lap weld. Use the 3c setting for this on 1/2 the pannel and 2.5b setting on thr other half. Weld a 2" line, skip an inch and wait 10 seconds contemplating and adjusting your techique (not settings).

After that do a butt weld with no gap same thing

Then when your done with all that drill some 1/4" holes and weld them up. Use the a 2.5b setting or even 3b (c will make to much heat). Work in tacks around the hole till you have tacks all the way around it, then lay a quick bead over those tacks and a small bit in the middle to join it. This will teach you how to prevent form just burning through the metal when you hit thin or rusty spots. Go up to 3/4" holes when your confident.

When you can do all that you'll be able to really handle welding on the body.
Good luck and keep us posted!

rcvd my eastwood sheet metal guage today, I mentioned it above, and my signs are 20 gage.

edit: 22 gage with paint fully removed.

nice little handy tool, about 3" diameter

I had my oxy/acetylene gauges rebuilt by a shop and the old codger behind the counter said you always want to purge the lines to take the pressure off the diaphrams so I always do. Do it on my mig also. My Hobart has a purge setting so no wasted wire. To the OP just keep practicing you will get the hang of it. You also might try making tiny circles as you push/pull the wire to spread the heat/bead around a little. Have fun.

If you go with the .023 wire............ don't forget to change the contact tip.......doesn't weld right if you forget. Ask me how I know ! I use the sp-135 welder with .023 and it works great for my projects.

I think i'm gonna hit home depot today for 023 and tips.

here is a great wire change video with warnings

http://www.youtube.com/watch?v=gPL1x16ZCmk

I thought my mig was different than most. as my nozzle and tip can off together. but I realized today that the diffuser was coming off with my nozzle. I used my easy out to disassemble into the 3 parts. whew : )

Hey Jim,

Couldn't help but notice.. looks are you using 100% argon shielding gas?

Jeff

for a minute there - i thought - SHIT

but here is the label