Sonix

iTrader: (1)

I have a few questions about TIG welding if I may:

-Can you TIG weld AL with DC current? Is it harder, or *impossible*?

-Does welding AL take loads more current than steel? I could weld 1/8" mild steel with 70A lets say, what about 1/8" AL?

-If I was going to weld 1/8"->3/16" steel, should I use a 3/32" tungsten tip ? And what size filler would be best, 3/32 as well?

-TIG filler material isn't as common as the other flavors of welding, and is substantially more expensive. Isn't MIG wire and TIG rod fairly similar in material composition? I mean, couldn't I just grab a small spool of 1/16" diameter MIG wire and just pull some off the spool and cut if off and TIG with it?

Thanks

junkcltr

iTrader: (1)

DC with alum. is possible. I have used some alum. 4043 ARC rods that are for DC. Cleanliness with alum. is most important. Both ARC and TIG is constant current.

It does take more current due to quicker transfer out of the puddle area. If you are using DC then you are dumping more heat in for a given amp number than HF AC, but lose the cleaning action. I would pay attention to the torch temp. so you don't burn it up.

For 1/8" plate I would use a 3/32" tungsten. I use 3/32" for everything. I like 1/16" filler rod for most of the alum. stuff. For the steel I cut pieces of .045" ER70-6 off of a mig roll that I got for free.

Sonix

iTrader: (1)

Sounds awesome, thanks! Exactly what I wanted to know.

I think i'll get a little air cooled TIG torch for my weldinator(tm). The torch is rated at 130A, and i'll probably just use it for AL and some detail work on steel. Any thick stuff will be steel or SS, and i'll just use 6013 ARC rods or 316L type ARC rods.

100% Argon would be good for MS, AL, and perhaps SS if I so desired?

AlkyIROC

You can run 100% Argon for everything but it's more expensive that a steel mix that also uses CO2 for when you're welding steel.

I've seen those little 110v TIG machines sold at Princess Auto. They would be good for a hobbyist but just don't have the amperage for any real welding (roll bars, frames etc). For that, you should be using a 220v machine. I considered buying one of the 110v TIG machines but decided against it.

Sonix

iTrader: (1)

They do what, 90A? TIG would be easy to do a wide weave, you don't have to worry about chipping off flux. I'd think you can do a deep root pass then a few on top and you could do 3/16" steel plate easily. 1/8" in a single pass. Tubing on a roll cage is 1/8" wall, and frames are probably 1/8->3/16". The plates for a roll cage are 1/4", but since you're welding them to 18AWG sheet metal you can't use the amperage to burn into 1/4"...

Hmm, i'll see what a small bottle costs... I may get a 75/25 AR/CO2 mix to start with steel, then if I ever need to do AL I can switch.

I'm looking just at the torch addon kit to add to my stick welder.

AlkyIROC

I bought the gas regulator for my MIG machine at Princess Auto years ago. I bought a steel mix bottle at House of Tools. It's cheaper than paying an annual rental fee considering I've owned it for over 10 years now. Bottle purchase is a couple of hundred dollars. Whenever it's empty, I take the bottle back to HoT and pick up a new filled one. I think it's around $50 for the exchange.

Sonix

iTrader: (1)

Hey right on, thats exactly the kinda advice I was hoping for. HoT sells bottles? Excellent. We're talking about the 4' tall BIG suckers? That's fairly pricey, but I guess that's mostly for the bottle itself.
Thanks

AlkyIROC

Not the tall bottles from HoT. They have the ones that are only a couple of feet tall. The tall bottles you have to get from a gas supplier such as BOC, Airgas etc. Buying bottles isn't cheap.

Sonix

iTrader: (1)

ah, ok.
Buddy at work told me he pays $75/year to rent a bottle from air-liquide. Company discount. I guess that includes the contents of the bottle. Sounds like a steal of a deal, i'm going to look into that one.

Vader

I've been renting my cylinders for about 25 years. The nice thing about that the is hydrostat teting is covered in the rental. If you own the cylinder, you may have to pay (or pay more for exchange) if the tank is due for testing. Check out all the prices of all your options. Your results may vary.

Blue-Beast

When I first got bottles, I rented the 2 that I needed (oxy/acce). I had to take them to the place I rented them from to have them exchanged, which was a pain and usually tied up my whole lunch hour. When my 1 year contract was up, I purchased the 2 from a local welding shop (I opted for the 4-footers as well) and now it takes me a whole 5 minutes for in-n-out. Yes it costed more initially, but I now have the luxury of exchanging them where I want to, and the big ones last much longer.
When I bought my mig welder, I purchased the bottle also. Since the MIG is efficient on the gas, I got a medium size bottle of the C02 mix.
Same as the new TIG, I purchased the bottle for it too. It uses more gas than the mig so I had to pick up the big bottle.

I have never paid to have a bottle certified, that is done by the refillers.

Sonix

iTrader: (1)

Ok, finally got my TIG parts from EBAY now. Going to get a bottle tomorrow. Buddy's wife works at Air Liquide, might get me a deal here

Now I have TIG parts - and no instructions. It was fairly intuitive but a few questions if I may;

- What's the difference in cup size? What does that change, amount of gas flow, or area that the gas is in?

- There's a round **** on the back of the torch. What's that for, gas flow? I assumed the regulator would be for that? I think there's a **** on the regulator, so i'm guessing it's to adjust flow rate? (i'm not talking about the back cap)

-Is the only purpose of a back cap to protect the tungsten backside?

-The tungsten is supposed to be the non-consumable electrode. If that's true then I wouldn't need to buy more, so... How fast should I expect to "use up" tungsten? red (2% thoriated) or should I go for the ceriated? (steel use)

I'm sure i'll come up with a few more questions when I hook it up and try it. Thanks

Blue-Beast

My tig came with a regulator. I ditched it in favor of a flow regulator. It was $80 for a Victor kit, but I use 75% (just guessing) less gas now.
The only wear that I've seen on the tungsten is from grinding off the contamination.

Sonix

iTrader: (1)

Interesting... I got a flow regulator I think.

I just picked up a "size 16" bottle, or 2.75m^3 of pure argon. It was $55 to rent it per year, and $69 for the contents. Not bad. I just need to build a bracket to mount the bottle to my cart, then i'll be trying it out.

jwscab

I dunno the actual specs of your welder, but there are some things I can answer, and some questions and suggestions to throw out there.

the tig torch has a gas valve on it, that's the ****. Since you are retrofitting a stick welder, you have to have a way to control the gas flow, otherwise, you would dump it pretty quick always on.

the back cap not only protects the electrode (HOT with voltage when 'on'), but it prevents gas escape from the back of the torch.

make sure you observe the correct polarity on DC, for TIG, thats DCEN (DC, electrode negative). the other way will dump too much heat into your electrode, and melt it.

you will need to perform a scratch start. to do this, (I never have), I have heard that you can place the torch near your work piece, and flick the filler material between the two, like lighting a match.

you will need a regulator, and you want about 15cfm plus or minus a few based on your weld. The gas cup basically provides the shield area, also based on the weld situation, usually a #7 or #8 should be fine.

the thing to remember here once you start practicing, is that you have no control over the current as you weld, you may need to weld faster as the pieces heat up. its not easy to learn this way, but you can really understand puddle control.

you can use mig wire, but its much easier with thicker, purpose made tig filler, as some joint you need to really pump the filler in. One trick is to grab multiple strands of mig wire and twist them together to get the right amount of filler.

you will use more tungsten than you think.....its tough to get that electrode there and nice and stable without sticking it while learning. If you tend to run hotter, as well, you can run up to the limits of the 3/32" and it will start to melt.

as for aluminum, you can tig aluminum with DC, known as Heli-arc, for one specific reason-helium. you will need lab grade helium ($$$$), in order to get great welds with AL on DC. if you have AC on that machine, give it a whirl, just remember that the current rating will be alot less, since it will be putting half a cycle of power into the elctrode, rather than the work piece.

good luck!!!!

Sonix

iTrader: (1)

ah, ok. Good info, thanks.
Yea, i've used the stick machine a fair bit, so scratch starting doesn't scare me too much. That's a neat trick, ie. flicking the filler in there, i'll try that.

I was at Air Liquide today (welders heaven). I picked up 1lb of 70SR or whatever TIG rod in 1/16". Ok, I guess i'll use that **** for gas flow. I might still get a gas solenoid (nitrous solenoid perhaps), but for now i'll stick with the **** and see how it goes.

I only have a 125A air cooled torch, and my welder won't be producing much more than that, so I think 3/32" should be good. I also have .040" and 1/16" tungsten, so I can play around with the WEE stuff.

I'll probably get a chance to fire this up and give it a try early next week.

junkcltr

iTrader: (1)

jwscab covered just about all of it. It sounds like you are ready to go. With that torch you will be running the 3/32" tungsten and smaller. I use 3/32" for almost everything.

Adjust the regulator at the tank with the torch valve open for the correct cfm for the material you are welding. I have never tried TIG scratch start but I hear it is easier to learn using a piece of copper against the steel. Start on the copper and carry over to the steel work piece. The amount of tungsten you use will depend on how often to touch the tungsten to the work.

Good luck. TIG welding is fun to learn.

EDIT: What power supply are you using?

Sonix

iTrader: (1)

OH YEA! I totally forgot about the copper plate, I remember hearing that once upon a time... Is that because the copper conducts better, so you can start an arc from a ways back? Then bring it in closer? And I guess you won't be melting either the tungsten or the copper then...?
Hmm, i'll get a little plate if I think of it.

-J

junkcltr

iTrader: (1)

When I first started with TIG not long ago I used a copper battery lug to form my tungsten for alum. welding because the directions said to. The thing is that copper can take heat and will not melt. I later just learned to form the tungsten on alum. The thing with copper is that electrically it conducts excellent and thermally it conducts excellent. So it is easy to start an arc and not easy to melt and contamite (sp??) the tungsten.

You will know when you mess up the tungsten. The tungsten arc will change color to a yellow bluish arc and the weld will be porous. It will make an ARC or MIG weld look excellent in comparison. It will look like you are welding pure rust.

EDIT: You will still have to scratch start on the copper.

jwscab

Oh, I forget to add, if you are interested, hobartwelders.com has a great forum for all kinds of info....it's where I picked up a bunch of this stuff before I started messing around with the tig.

you mentioned a gas solenoid, that would be a good idea, play with the **** first, and then work on building the solenoid assembly. it will be easier.

one other thing....the most important part of evertyhing is your gas shield, so....remember to pre-flow and post-flow your gas, that is, turn it on a couple seconds before starting the arc, and leave it on till the weld isn't red. this will prevent oxidation on both the weld and tungsten, and cool the torch.

have fun, it gets addictive.

83 Crossfire TA

iTrader: (2)

Not for tig… you pretty much use straight argon for everything with the possible exception of DC welding aluminum and magnizium where you might add a little He to make for a hotter arc. CO2 will destroy the tungsten.

You need to totally change your thinking for tig. That would work for stick or mig, but there really is no such thing as a wide weave while TIGing. There are things that I find simple with a MIG that you would think would be even easier with a TIG that I find very difficult, like filling holes. I can pretty much do them on the fly with a MIG, where with a TIG if I’m going to have any chance I need a copper backer.

You’re looking for a big, stagnant puddle of shielding gas around the weld. Basically too small a cup or too much gas velocity will make turbulence that will suck surrounding O2 into the weld. Basically, you want to use the largest cup that doesn’t get in your way.

It’s a manual gas valve for a tig welder that does not have one. It will not really work as a regulator, you still need a separate regulator which decreases bottle pressure to 50psi and lets you set the flow rate at that pressure.

That pretty much depends on you and how fast you contaminate it. Well, and how tolerant you are of arc wander as the tungsten looses it’s sharpness.

Types… there is theory and practice. Basically 2% thoriated or one of the thorium replacmenets, ceriated or lanthanated are supposed to be used for everything that needs a sharp point, pretty much everything besides aluminum and magniesium. Pure or zerconiated are supposed to be used for aluminum/mag. Real life is totally different. The 2% Thoriated works great for everything, even though the industry is trying to get away from it. I can’t seem to get consistent results with either pure or zerconiated in aluminum, and have never had thoriated flake like it’s supposed to from the heat of aluminum welding, it just works. The replacements… well 1-1.5% lanthanated, for me at least welds like a blunt pure tungsten on steel, unsteady arc, doesn’t keep a point… supposedly higher percentages take care of that but I haven’t tried it. Ceriated… well it’s not quite as good as thoriated when new but it gives up it’s alloy as you weld, so it sort of stops working and you have to regrind or eventually replace it.

I’ve also used some of the new “unspecified rare earth” (ivory band) and besides their lack of availability any way but mail order and cost, I’m not sure that I could tell them from the thoriated.

Bottles… I usually suggest buying the biggest you’re allowed to in your area. Refills only go up a few $ per bottle size even though capacity almost doubles. In my area the biggest you can own is an 80 (the one that’s about 4’ tall and 7” in diameter), costs about $120-150 to buy a bottle but refills cost $35-60 (originally I usually got stuck paying closer to 60, but as I got more refills, the price dropped to 35 at the same place for the same stuff, not sure why).

Sonix

iTrader: (1)

Interesting stuff...
Well I guess i'll find out when I get a chance to try it.
I'm waiting to go home for christmas, i'm getting my dad to build me a wood bracket to mount my bottle to my welding cart. A sawzall just won't make good enough straight cuts...

Hmm, i've got 3 pieces of 2% thoriated, but the guy at the shop sold me on the ceriated, saying the industry is moving towards it. So I have a piece of that to compare. I was hoping the thoriated was "good enough for everyone last year, then it's good enough for me now...". Plus it's a bit cheaper usually I think.

Can't wide weave with a TIG eh? Damn. Well I'm still looking for a bigger engine for my welder, but for now I can only manage maybe 80-90A, so i'll have to make do with that. But since there isn't any danger of inclusions of flux, I can at least do a multi pass eh?

This is going to have to wait until after christmas, I don't want to do anything with it until I have the bottle mounted, and i'm not supposed to be doing any garage work for 2 weeks after laser eye surgery... I'm going squirrelly not allowed to go in there!

Rob Wade

Well......hows the tig welding going. One other item I can ad to this. Since you are using a scratch start tig you are going to use up your tungsten a little quicker. Since you actually need to touch the tungsten to the material your welding it does get "mucked" up quicker. Be patient....tig welding is completely different from other forms of welding....aside from oxy/acetalyne.

Sonix

iTrader: (1)

Oh right, forgot about this thread. Got the bottle mounted and have started practicing. Yea, i'm mucking up the tungsten very fast! It actually works ok until you get it VERY messed up. It does remind me a lot of torch welding, hold the "flame" in place until I can see a puddle, then start dipping in my filler and start moving.
Now i'm using (using up!) 3/32" ceriated tungsten. I'm using 1/16MS filler, or .035" MIG wire. The mig wire was $16 for 11lbs, vs $8 for 1lb of the TIG rod.

So far i've tried welding bolts to flat plate and whatnot. I'm not getting enough penetration just yet, gotta work on that. It seems easier than stick to me though, I can see how much metal is going into the workpiece, rather than just seeing the flux.

Rob Wade

In a way it is easier than stick welding. Without all the flux in the way you can really see what happening and control your puddle better. The most difficult thing I find about tig welding is that you have to do a fair amount of it to STAY good at it. I do mostly heavy stuff with our MM350's and 450 mig, so when I do need to do some tig welding it takes a little bit of practicing to get the hand speed back. Wait till you try some out of position stuff! In some ways the smaller puddle helps you in out of position welding but you lose your "place" to rest your torch hand!