mig questions, sample pics added Options

[jimkelly]

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

[infraredcalvin]

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.

[jimkelly]

all good and helpful comments - thanks guys!

[Elliot Cannon]

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.

The difference might be, that my gauges and valves were made in Shanghai. (IMG:style_emoticons/default/av-943.gif)

[speed metal army]

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??"
(IMG:style_emoticons/default/rolleyes.gif) Corny,but true.
Practicing on uncut material is good. Laying beads, over and over. Then work on lap joints.. Tees. Outside corners etc.

[tomeric914]

.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.

(IMG:style_emoticons/default/welder.gif)

[jimkelly]

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

[76-914]

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 (IMG:style_emoticons/default/av-943.gif) ) 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. (IMG:style_emoticons/default/slap.gif) PS, get some .023". You'll need some and a small spool is only about $7.

[McMark]

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

[Brian_Boss]

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.

[jimkelly]

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

[jimkelly]

got it - beads are for butts (IMG:style_emoticons/default/bootyshake.gif)

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

[relentless]

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.

[ChrisFoley]

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.

(IMG:style_emoticons/default/agree.gif) 100%

[aharder]

This thread makes me want to go buy a welder so I can try all the stuff I just read (IMG:style_emoticons/default/welder.gif)

[bigkensteele]

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.

[Andyrew]

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.

[Andyrew]

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.

[jimkelly]

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.

[jimkelly]

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.

[rick 918-S]

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=