Advice for a TIG beginner?

[sd455dan]

AndNow everyone's convincing me I need to get set up properly for TIG! Those are all applications I could use.


Aside from the bedframe/tray chassis described above, here are typical past projects:

Fabricated a drawbar from junk materials for a spike harrow. Ground through most of the rust then used the big ac stick welder.

The completed drawbar project including a 3-point lifter built from exercise machine parts.

Detail. I welded 'ears' on the lifter mast to pin it to the Qhitch. This was the last thing I used the AC HF-90 flux welder on before I replaced it with a DC 110v welder.

... And a trailer hitch welded to front bucket using the DC 110v Century-135 welder that replaced the AC-only HF-90. The Century did much nicer work. I recently sold the Century for what I had paid for it. (The HF Mig-180 duplicated it and also does more).

I agree about the bed frame material- it is a little funky to weld with although it has good strength it does seem to be harder to get as clean of weld as new mild steel- just from the welding I have done re-purposing it.

Tig does seem to make stronger welds sometimes- i have the old Gilson riding mower under the avatar and both sides have suffered snapped off spindles for the mower blades. tried and succeeded welding the blade support back on with my mig multiple times over the years but was lucky to not lose both blades a couple times each mowing season. I decided to have a go with the tig and both blades have stayed on with no sign of failure- no real explanation and the prep work was no better than done for the Mig process.

Tig also came in handy a while back saving an old set of jumper cables, i was to cheap to throw them out and didn't want to spend the money on new ends, cleaned up the jaws where the copper used to be crimped and used the Tig to melt the copper and it fused right to the steel jaws. that set of cables is better than when i bought them as far as transferring current to start a dead vehicle.

As was pointed out welding things to bolts small fittings and working with different metals- tig is in a class of it's own, Eventually i want to build some custom hedders and even an aluminum air intake out of AU for my Volvo Penta boat engine.

There are times when a need comes up to weld some really fine work and or special metal and it becomes obvious very quickly that a Tig is about the only solution to solve a welding problem,

Get or even rent a Bottle of Argon and give Tig a try, It is kind of addicting and is a great way to round out your welding equipment

 

[sd455dan]

Why would anyone want to stick weld on AC I'd a DC machine is available

Massive Arc Blow... happened a few times to me ( old steel magnetized??) and A/C although more spatter did in fact stabilize the arc

 

[California]

Massive Arc Blow...

??? Wind, magnetism, ???

 

[k0ua]

??? Wind, magnetism, ???

Arc blow can occur when you are attempting to weld magnetized material. AC welding will minimize this problem. It does not occur very often. The magnetized material can cause the DC arc to "wander".

 

[dfkrug]

The Vulcan Pro Tig 200 AC/DC does in fact have A/C welding capability

I stand corrected.

The top-of-the-line Vulcan when I first got the announcement from HF was the
OmniPro 220, which is DC-only TIG, for $729. They still sell their old top-of-line TIG (DC only) for
half that.

The Pro-TIG 200 (DC and AC) seems to be $100 more than the OmniPro 220.

I suspect more announcements from HF are coming.

 

[dfkrug]

Why would anyone want to stick weld on AC if a DC machine is available

Don't all AC-DC buzz boxes put out a lot more current on AC? I think my Miller Thunderbolt
puts out 230A on AC, and only 150A DC, IIRC. I never go that high, however, as my preferred
rod is only 1/8".

Anyone use 3/16" rods?

 

[Fallon]

Don't all AC-DC buzz boxes put out a lot more current on AC? I think my Miller Thunderbolt
puts out 230A on AC, and only 150A DC, IIRC. I never go that high, however, as my preferred
rod is only 1/8".

Anyone use 3/16" rods?

If you just slap a diode on an AC line, you end up with a half a sine wave of DC at half the average voltage. Filter & smooth it out & it smooths out but drops the average voltage out a bit. Rectifier - Wikipedia

A full wave bridge rectifier Diode bridge - Wikipedia can utilize both the + & - sides of the AC wave & turn it into double the DC voltage a single diode can.

All that is voltage, not current, but if you are using the same transformer less volts means less amps. So it passes the thoery sniff test that an AC/DC box will generally do less amperage on DC than AC.

 

[LD1]

Same holds true for welding/penetration too.

If you are used to welding @ 125a on AC.....you will find that 125a on DC is ALOT hotter. Maybe ~90a on DC would be closer to weld characteristics of 125a AC

 

[California]

Same holds true for welding/penetration too.

If you are used to welding @ 125a on AC.....you will find that 125a on DC is ALOT hotter. Maybe ~90a on DC would be closer to weld characteristics of 125a AC

So my TIG/stick unit rated 130 amps DC for stick would more or less match the upper range (not peak) current the 230 amp AC buzzbox provides, in practical use?

I don't think I ever set the big welder to max except for heating with the carbon arc 'torch'.

 

[Lnk]

"As was pointed out welding things to bolts small fittings and working with different metals- tig is in a class of it's own, Eventually i want to build some custom hedders and even an aluminum air intake out of AU for my Volvo Penta boat engine. "


I would love to help you with your Au intake. Can I keep the scrap? :laughing:

Lnk

 

[dfkrug]

Same holds true for welding/penetration too.

If you are used to welding @ 125a on AC.....you will find that 125a on DC is ALOT hotter. Maybe ~90a on DC would be closer to weld characteristics of 125a AC

I don't know how you can conclude that. Current causes heat, and AC current of higher amperage (RMS) heats up
conductors like DC current does. I am not talking about weld characteristics such as penetration, polarity, rod
type, spatter, etc. Heat.

 

[LD1]

I don't know how you can conclude that. Current causes heat, and AC current of higher amperage (RMS) heats up
conductors like DC current does. I am not talking about weld characteristics such as penetration, polarity, rod
type, spatter, etc. Heat.

If you ain't talking about weld characteristics then what are you talking about? And why is it relavent to the thread?

Penetration, heat in the work piece, etc. 125a ac is pretty close to 90a DC. That's all I'm saying. Don't read any more into it than that.

If you are used to 125a ac, then go to 125a DC....it's gonna burn in alot hotter. 125a on DC would be about like 160-170 on AC

 

[California]

125a on DC would be about like 160-170 on AC

Ok that was my question.

I was surprised how fast the 2/3 dial setting on my TIG (130 amp Stick) ate a 1/8 rod. It seemed similar to setting the old buzzbox in the upper third of its scale.

 

[LD1]

Remember AC is alternating current.

Then there is the whole dcep and dcen thing. Dcep penetrates deeply. Dcen....don't penetrate much.

With AC, you are spending half your time on dcen , the other half on dcep.

If you can straight up run dcep (which is what most rods are ran at on DC), you get much more penetration on the same amps.....
Or in other words, could can dial the amps down a good bit for similar penetration (heat) characteristics of ac

 

[sd455dan]

"As was pointed out welding things to bolts small fittings and working with different metals- tig is in a class of it's own, Eventually i want to build some custom hedders and even an aluminum air intake out of AU for my Volvo Penta boat engine. "


I would love to help you with your Au intake. Can I keep the scrap? :laughing:

Lnk

Yeah- actually (aluminum air intake)
I did not mean to replace the cast aluminum dual carb factory intake,
Only to weld up a sheet Aluminum air box cover for the carburetors. it was missing when i bought the boat and without it water can intrude into the engine when it rains.
Have not been able to find a factory one.

As far as building steel custom hedders - it would be to replace the used GTO hedders that I cobbled up to fit a punched out 455 that I (stuffed) into my 1984 Mazda RX7.

Oh and no you can't have the scrap- what do you think I use to build this stuff with:laughing:

 

[woodlandfarms]

Uhm Au is the abbreviation for GOLD. Glad you can build so much with it.

 

[sd455dan]

You are right, what was I thinking-

wish I had some (scrap) au for now Al or Alum will have to do.

heck, some days i am so poor- I can't PAY attention.

 

[dfkrug]

If you ain't talking about weld characteristics then what are you talking about? And why is it
relavent to the thread?

I was pretty clear that I am talking about heat. You said lower amperage DC will be hotter than a higher
amperage AC. You also asked, perhaps rhetorically, "Why would anyone want to stick weld on AC I'd a
DC machine is available"?

My answer was 3/16" rod, which will require the full amperage of the welder, over 200A, which will
be A/C for the common tombstone or other buzz-box.

 

[BeezFun]

I can't imagine an application for this here. My welding is mostly repairing farm hand tools and tractor implements, and minor fabrication.

I have the same applications and switched over to tig because of the fire issue and it's more portable. Welding in the barn or a field used to mean spending the next hour with a fire extinguisher close by hoping some spark didn't fly into some dry hay. With tig I don't have to worry about that. It's easier to move around and will run on 110v, which is fine for most of the small stuff I weld like gate or corral panels. I have a Lincoln tombstone that I'll still use on occasion if I can move the material up near the shop.

 

[k0ua]

Uhm Au is the abbreviation for GOLD. Glad you can build so much with it.

I noticed that, but didn't say anything. I figured if he want to build with Gold, well let him. :laughing: