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parsonsj
09-13-2005, 05:09 PM
Hey guys, here's a welding sample (stainless steel exhaust) from this past weekend. I want to give some credit to Matt@RFR, because his posts about heat, color, correct rod, etc. have been useful for me. My welding has really improved recently, and I appreciate the help.

jp

Nine Ball
09-13-2005, 05:15 PM
lol, your welding improved AFTER you completed the fab work on the car? hehe

I think you got a LOT of practice there, bud.

Tony

parsonsj
09-14-2005, 03:56 AM
LOL.

I'm mostly talking about aluminum and stainless. Low carbon and 4130 steel is a lot easier to get high quality welds, at least for me. But I do look at my cage and wish I could re-do it. It's only the paint that stops me.

jp

Matt@RFR
09-14-2005, 07:05 AM
Thanks John. Hopefully you're not the only one progressing. Settings?

And I have to ask...what's the inside look like? :)

parsonsj
09-14-2005, 07:26 AM
Settings: 35A, 11 CFH Argon on torch, 4-5 CFH Argon back purge (as low as my regulator will go and still flow something), .040 tungsten, .040 filler, 3/8" stickout, gas lens.

Inside of tube looks like the outside, though the original edges are visible in places and the stacking effect is less prevalent.

jp

Matt@RFR
09-14-2005, 08:46 AM
Why so low on the torch argon? Whatever the reason, it seems to work.

Most of the time when you have inconsistent penetration on something like this, if you feel amperage was consistent, it's because you start out with a travel angle near perpendicular to the work, and as you go arond the tube, travel angle increases to a point that the arc (penetration) is almost tangent with the tube if you let it go that far. It's a bitch. :)

It may help you to stand the tube up vertically. That lets you kind of walk around the tube as you weld, keeping travel angle consistent. Unfortunately, most of the time header tubes won't work in a positioner due to their odd shapes.

parsonsj
09-14-2005, 09:35 AM
You're right about the angle of the tube. I try to roll my wrist as I work up the tube so that the arc is perpendicular, but that's difficult at best and often impossible.

Torch argon comes come my handy-dandy Lincoln welding calculator. What value do you use when welding stainless tube (.049 or .065)?

jp

Matt@RFR
09-14-2005, 09:56 AM
Yep. Small tube welding is definetely an aquired skill, no matter what process is used. Stick is the worst.

I flow 15cfh at the torch, but that's with a #8-#10 cup. Cup size makes a difference here. (My girlfriend taught me that. :) )

For back gas, I generally flow 5cfh. The way I do it is set my regulator to like 30-40cfh, and I have a ball valve at the end of my purge hose. That way you can go WOT with the ball valve and fill the weldment quickly, then back it off and watch the regulator until it hits 5cfh.

68protouring454
09-14-2005, 11:20 AM
man you really are the hero welding guru.
KUDOS TO YOU MATT, for being so handy with a welder

Matt@RFR
09-14-2005, 11:24 AM
:) Thanks for teaching me everything I need to know.

Nine Ball
09-14-2005, 01:24 PM
A local shop closed their doors a couple weeks ago. I'll be picking up a 1-year old Miller Econo-TIG setup from him for $1K with rods and accessories. Yeah, its a barebones system without any fancy controls, but it should be okay for doing exhaust, turbo piping, and rollcages. I really want an inverter type that runs on 120V, but those are over $2500. At least I can give this Miller a shot and see if it works for me, and I could always sell it for what I paid for it later I suppose.

Anyone with experience using the Econo-TIG Miller?

Matt@RFR
09-14-2005, 01:56 PM
In reality, that should do everything you need on an automotive project. It'll be able to weld 1/8" aluminum...possibly 3/16" butt welds.

I've never used that particular model, but I can tell you two things up front: 1) The fixed duration post flow will eat up a bunch of gas. My old Synchro 180SD was set at 15 or 18 seconds! The most you would ever need is around 6-8 seconds for steel and aluminum. 2) If you get stuck with an air cooled torch, you'll soon want to throw it off your roof (highly recommended!). Invest in a water cooled torch if you have the resources, and you'll never look back. Plus, the torch can stay with you as (if) you move to a bigger machine.

parsonsj
09-14-2005, 03:48 PM
Tony,
Are you sure that model has AC? If not, you won't be able to weld aluminum.

jp

Matt@RFR
09-14-2005, 03:53 PM
Econo TIG (http://www.millerwelds.com/products/tig/econotig_ac_dc/)

parsonsj
09-14-2005, 04:00 PM
LOL. Shows how well I know the Miller line. I thought the Synchrowave was their bottom of the line AC machine.

Tony, looks like a good bargain.

jp

68protouring454
09-14-2005, 06:05 PM
i have seen those for 5-700 a bunch of times used, that is getting up there, you can buy a used miller 180sd or a lincoln 175 tig for 1,000-1,400 used and will be way more machine although it will need 220, 50 amps
jake

Nine Ball
09-14-2005, 06:43 PM
One good thing is that I know the seller, and he takes care of his stuff. He is also including everything but the bottle, plus spare rods and torch parts etc...

HotRod4PaPa
09-15-2005, 04:47 PM
Hey Matt. I have a 180SD, and yes, it does eat up gas! Can the post flow be reset to 6-8 seconds on this machine? Also, would it be very difficult and expensive to switch this machine over to water cooled? Thanks for any help you guys can give me.

parsonsj
09-16-2005, 06:31 AM
I can't recommend a water-cooled torch enough, especially if you're welding aluminum. My Johnny Cheapass solution was to buy a water solenoid from Lincoln and connect it to the gas solenoid. So when there is gas flow, I have water flow. I tapped in to my house cold water supply and stuck a ball valve in between it and the welder and put the output back into the waste plumbing. No expensive chiller or fluid required.

Before a welding session, I open the ball valve to let cold water flow to the solenoid, then while welding the water flows (when gas is flowing) through the torch and on to the drain. I've done a lot of welding since then and haven't noticed any difference in my water bill (even when my power bill goes up from a lot of welding). When my welding session is done, I close the ball valve. It's no big deal: when I open the main bottle valve, I open the water valve. When I close the main bottle valve, I close the water valve.

The advantage is a cheap water-cooled torch, the downside is that I'm using tap water. Eventually it will put deposits in the torch and I'll have to clean them out with vinegar or something. Also, it limits where the welder can go: it can't be moved any farther than the length of the water lines.

But still: recommended.

jp

Matt@RFR
09-16-2005, 07:22 AM
I believe that the 2003 and newer 180SD's have adjustable post flow, but don't hold me to that year.

Water cooled torches not only let you weld longer at higher amps, they are WAY smaller too. You can manuever them much more easily, and they just look cool. :)

Another, slightly more expensive, way to go about a home brew water system is this:

Buy this (http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=6970&productId=200280274&R=200280274) pump.
Build a water tank. 4-5 gallons.
Plumb torch to pump and tank.
Fill tank with distilled water and add a gallon of Miller's additive.
No valves are needed.

Or, if you have the money, the Coolmate 3 (http://www.millerwelds.com/products/accessories/water_coolant_systems/) is the real deal, and really does work much better than most home brew setups. However, you wouldn't notice the difference unless you used it for a few hours straight.

parsonsj
09-16-2005, 07:44 AM
Matt,
Can you recommend a similar pump from McMaster-Carr? Or let us know what criteria you used to pick that particular pump? I've got an unused aluminum fuel tank complete with AN fittings just sitting around taking up room. Might be fun to get something useful from it.

jp

68protouring454
09-16-2005, 08:05 AM
i also made a tank that is about 4-3/4 gallons, and made a cart so i could mount it below my lincoln tig welder.
i got threaded bushings from msc, that were 1/4 pipe and drilled hole in tank and welded them so i could run a hose from pump in tank to bushing, then screw feed line of water torch into top side of it, then i welded another on other end of tank so that return line screwed in, mine works awesome, otrch stays so much cooler, and i can only imagine if i tig'd alot. i used same pump as matt, as he got a new pump, by the way i ned to finish my tank and make a covere for access hole for pump, well make it so it screws on, i have it setting on now.
i got my water torch used from my gas supply house for 60 bucks, in new condition, then a few fittings and some aluminum and i got a killer set up, probaly have like 200 into whole deal and i can cart it anywhere in my 3,000 ft shop and weld.
jake

Matt@RFR
09-16-2005, 09:35 AM
The brand is Little Giant. I'm sure others would work, but those are pretty cheap and quite durable. Pick a pump that will pump a head of water higher than the torch would ever be. In other words, if you forsee welding on the top of a 10' ladder, you need a pump that will pump a head of water higher than 10'. Preferably by a factor of 2. The pump I have will pump a head of water 17.5' if I remember correctly. I don't have time to look up pressures/flow numbers, but I would think any pump that can pump a head of water that high would have the other numbers to support a water cooled TIG torch setup. They flow very little.

If you use this setup, and have a pump that produces pressure greater than 5psi or so, you can NOT have a shut off valve in the system. TIG torches are not designed to have much pressure in them. I don't know what you're running, but my torch is $300, so no pressure for me. :) Also, with a water cooled torch, if you forget to turn the pump on and proceed to weld, you WILL be in the market for a new torch and power cable.

After awhile, the pump itself will heat the water up, so if it will be used for hours on end, a small radiator with a fan would be best. I used an aluminum Banshee radiator. :)

HotRod4PaPa
09-16-2005, 01:02 PM
Thanks for the help! I will have to go the "cheap system". I will start scrounging for parts soon. I am trying to pick up tig welding on my own. Are there any good instruction videos that might help me with welding mild steel tubing (1 1/2"X.125 wall). My biggest problem is undercutting the tubing at the edge of the filler metal. It seems to worsen as the tubing heats up; maybe half way through the length of the weld. I may be running too much amperage to begin with. I have been setting amps at 1 amp per .001" wall thickness.

parsonsj
09-16-2005, 01:56 PM
Sounds like it to me. You need to back off the amperage as the tube heats up. I'm amazed myself at how little filler metal most good TIG welders use, at least for steel and stainless. I saw a certified cage that looked like very little filler material had been used.

jp

Matt@RFR
09-16-2005, 04:12 PM
I have been setting amps at 1 amp per .001" wall thickness.
That's for aluminum, and even then usually isn't accurate. For 1/8" wall, you should be around 70 amps, give or take. Your amperage setting is very personal, so only you will be able to make it perfect. As a hint, though, you could weld that same tube with your machine set at 200 amps. It's all in the pedal, and with as much finesse as you can muster.

Undercutting can be lots of things. The most popular is not too many amps, it's a bad torch angle. If you're welding a 90º joint of the same thicknesses, your tungsten needs to be pointed into the root at 45º. If it's very far off of that, the arc can pull metal from the work into the weld in a place where you're not adding filler. If you want to prove this, fit up a tube/tube joint at 25º and weld the skinny side.

Along those same lines, if filler deposition is really shaky, it's possible to drag the puddle out of the weld, sometimes resulting in an undercut.


...at the edge of the filler metal.

That's called the toe.

If you're trying to space filler 'dabs' far apart to get the 'look', stop. If that's the case, that could be part of your undercutting problem - not enough filler. Also, for structural things like roll cages (I'm assuming that's what you're practicing for), all that technique does is add relatively large stress risers to an otherwise sound weld. The first attached picture you may have seen...the only reason I ran the weld that way is because it's "pretty", and it's a part for my parents entertainment center. :) A good structural TIG weld will look something like the last two pictures, with your 'dabs' as close together as you can get them. For reference, the last picture is 2 1/2"x.120" stainless tubing. Second picture is also stainless, and too hot. First picture is something like 3/4"x.120" DOM.

HotRod4PaPa
09-16-2005, 06:46 PM
I really appreciate you guys replying. I can relate to Matt's comment on co-workers catching fire. I just about let my buddy burn his shirt half off before I put him out. I was the fire watch! It's hard to get good help. Ha. Looks like I may be running too many amps to control with the pedal once the metal heats up. I also have a lot of trouble keeping the correct torch angle as I move around the tubing. My frame jig "32 Ford" does not rotate, so that puts me on my head at times. I try to keep an even width filler weld puddle going and don't concentrate on the "row of dimes" look. I figure that will take care of itself once I get this other figured out. One of the reasons I have been using this amperage setting is because it seemed to take too long to heat the metal enough to get the weld started, but now I have created the undercut problem. I will cut the amperage down and concentrate on keeping the "dabs" as close as possible. I will let you know how this turns out. Thanks

Matt@RFR
09-16-2005, 09:13 PM
Arc length plays a big part in all of this. Keep it as short as you possibly can. Like 1/16" or less.

Pictures will help immensely.

parsonsj
09-17-2005, 05:06 AM
ah yes, keep the arc length short ... but don't dip the tungsten into the puddle. I go through cycles. Some days I can weld all day, just touching up the tungsten occasionally as it oxidizes. Other days I dunk it all day long! And man, does that piss me off!

Here's a frustration, let's see if you have any ideas: when I'm welding with .040 filler rod, I have a lot of trouble getting precision about where the "dip" occurs. The filler just flops around since it's so thin. Man, that's annoying.

jp

Matt@RFR
09-17-2005, 09:12 AM
Cut it in half. Or do you do that allready? If so, less coffee? :)

parsonsj
09-17-2005, 09:37 AM
Yeah, I cut 'em in half. Maybe I'll try in quarters.

What's wrong with 12 cups of coffee a day?

jp

race-rodz-inc
09-17-2005, 04:32 PM
i wish this topic would have been around bout a year ago when i started tig welding on a regular basis... i allready went through the turn it down, turn it down, turn it down on the amperage.... control the pudle with speed (or lack of)deal. now i just need to work on the less cafine deal... some days im fine... other days i shake like a crack head thats been "clean" for 2 days. man those days of touching up the tungsten every 30 seconds really suck

boodlefoof
09-18-2005, 06:15 AM
Man that is bee-utee-ful welding! I have something to aspire to! :thumbsup:

Matt@RFR
09-18-2005, 06:29 AM
:).