Basic welding question - not 911 related.

[rnln]

This is not a car related question but I know there are manny people in here can give me an answer so please don't ditch me.
I am working on a 9' tall rack/stand for my Flat Panel TV. I am thinking of making it myself with 1"x2" and thick metal tube. I saw the lincohn 120v at home depot for good price, $200-$300 bucks. My question is if the weld, 120v WITHOUT gas, strong enough to hold things safe? The TV is almost 100lbs.
Someone suggested me that with gas, it will be good but without gas, who knows.

[wachuko]

Really depends on the how clean the weld is... not letting the slag run in front of your weld, making sure the penetration to both pieces is as even as possible...

Will this be your first welding experience?? Those small Mig welders work fine. Best to get some scrap metal and practice before you build something that will hold a TV...

[Zeke]

Actually, you get a hotter weld, hence more penetration, some factors being considered, with a wire feed. Just more splatter.

[wachuko]

Until I can save for a nice TIG welder I went with a inexpensive alternative:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=55250



I have been using this for fixing a Rail Buggy and the welds have been coming out great without using gas. I know that if I use gas I can get better and cleaner welds... but so far it has been working fine.



Fyi - those flat pieces were change for pipes as well... but the idea is for you to see the nice weld you can get with these machines.

[rnln]

Thanks guys for the tips.

wachuko,
the one you recommanded has great price but it use 230v source which I don't have. What is the diff in result between 230v and 120v one, without gas?
Thanks.

[Seahawk]

Originally posted by rnln
What is the diff in result between 230v and 120v one, without gas?
Thanks.

I do a lot of welding with wire fed MIG, without gas...120V, works like a charm.

Milt is, as is his custom, right. Key for me is that I'm not, thank god, welding for show,

You can always rent a welder, btw.

[rnln]

Anyone has enough knowledge to explain the diff. between ARC, TIG, and MIG?

[RickM]

With Arc (stick) welding the electrical flow goes through a hand piece that holds a welding rod. The arc of electricity between the work piece and the end of the rod melts the rod into the host metal. Flux is one component that makes up the welding rod.

MIG stands for Metal Inert Gas. Electricity flows through a wire that is fed from a spool and through a gun. The tip of the gun also has accommodations for inert gas such as Co2 or Argon (or a mix of both) to shield (wash over) the weld. If the gas did not flow around the weld then oxygen would contaminate and pretty much render the joint useless. Gasless MIG uses wire that has a built-in flux that does the shielding..as opposed to gas.

TIG stands for Tungsten Inert Gas. Here you strike an arc with a hand piece that has a tungsten tip. You then feed the welding rod into that arc to complete the welding process. Inert gas wash the work area to prevent contamination.

Each of these is dependent on an arc to effect the weld.


Stick(arc welding)











MIG












TIG

[Slider79SC]

With TIG welding is it better to use a draw method and put the filler in as you go or a push method and put the filler in front?

[rnln]

Sorry for silly questions but is each for different purpose or they are all the same purpose but different result? Which one is good for home use?
Thanks.

[RickM]

Stick welding is pretty much used for heavy welding. That's not to say you can't do delicate work IF you're very competent with your setup.

MIG is probably the best all around tool for the money. It's easy to learn and quite versatile.

If I were you I'd invest in a decent name brand unit with gas...or at least the option to add gas later. I have found my welder to be one of my more usefull tools.

[Zeke]

Originally posted by Slider79SC
With TIG welding is it better to use a draw method and put the filler in as you go or a push method and put the filler in front?

Unlike MIG, it's hard to go backwards with TIG. Compare TIG to Oxy/gas welding where the forward angle of the flame is preheating where you are going. MIG goes either way, depending on how hot you want the puddle ("pushing" is hotter; better penetration with the same current).

The new terms for the welding processes are GMAW (MIG) SMAW (shielded metal arc; stick welding) and GTAW (gas tungsten arc). The reason for the change is that the "I" in MIG and TIG stood for "inert" (gas). Sometimes the gasses used are not inert, such as C02. The "semi-inert" gases used for some specialized welding processes can also contain O2, nitrogen and hydrogen. In the basic cases, the inert gasses are shielding these types of gases from contaminating the weld. However, in controlled amounts, the non inerts help the weld quality.

The wire feed welding process is almost the same as the stick process with the electrode moving toward the weld and being consumed as a filler metal. However, the processes differ in the type of power used. The stick is mostly a constant current (CC) process where the voltage changes with the resistance or distance of the arc. The GMAW uses a constant voltage (CV) with the current flowing higher of lower depending, again, of the distance of the arc. A wire feed without gas is simply a flux core wire (FCAW) and works, once more, like the SMAW process with the flux providing the shielding gas as it is heated in the arc. You would reverse the polarity (another subject) for FCAW vs. GMAW.

GTAW uses the same CC process as the SMAW, but there are a lot of controls to adjust for the different metals. TIG or TAG (sub processes of GTAW; tungsten active gas vs. inert) can use AC or DC and positive or negative electrode. the AC frequency can be very high for a smooth arc, virtually uninterrupted. That would be for aluminum. DCEN (direct current-electrode negative) is for steel. The ionized electrons are flowing to the work in this process keeping the arc stable.



I’m writing all of this to continue to commit the processes to memory and I know it's more than most care to know. I was in welding school last year and had this all down pat. But, like anything else, if you don’t keep up on it, the knowledge starts to fade. And I only know the tip of the iceberg in terms complete knowledge of the science. But, I did write this, not cut and paste.

Best thing I ever did was to at least learn something about what I had been doing hap hazzardly for years.

[john70t]

Stick welding doesn't have the fine control as the other two. It relies on getting the rod close enough to start the arc but keeping it far enough away to not ground it (it "sticks" to the metal-pun intended).
The rod is coated with shielding flux which spatters and makes slag.

MIG welding(wire fed) is overall the most practical and is easiest to use-just pull the trigger. It will warp panels unless a "stitch" technique is used.
The gas-less type also has flux-coated wire and messier results.
The gas type uses pure wire(rod) and a shielding gas of CO2(with Argon depending). The gas does the same as flux and protects the melted weld area from oxygen contaminating it.

TIG welding doesn't use sacrificial rod like the others, and is most difficult to master.
On those fabrication shows, they quick tack together(without a face shield) the custom tailpipe pieces with MIG, then take it over to the bench and TIG weld it (the blue light) together for appearance.

[mb911]

Originally posted by Slider79SC
With TIG welding is it better to use a draw method and put the filler in as you go or a push method and put the filler in front?

draw=pull method?? Never taught that always a push from right-left using a dab technique or walk the cup and or wire.. The only reason to pull in TIG is for TI where you have to "backhand" it..

as to answer the question No it would not be adviasable to weld that with what you have there. it just is not safe..

I use to have a hobart handler that was 110v and that used 75-25, argon- co2 with .023 hard/soilid wire and that was more up to the task of what you need to do. but what I find with the cheapies that most often are owned by hobbiest have no place doing what they do with them

90% of all broken welds are broken because of 2 things

1st the operater error
2nd the weld was not "hot enough" or in the case of "MIG" welding the volatge could be to high with the wire speed not high enough causing for incomplete fusion. this can also be caused with to high wire speed and not high enough volatge(potential heat/amperage)

anyhow thats the welding teacher in me sorry..

[rnln]

Thanks so much for all the info guys. I still.. have no glue. Maybe getting a cheap or used one to get my hands on before I should ask/read more.
Again, thanks for all you info.