# Scratch start/Lift arc TIG acceptable?



## Mr.SBC (Dec 18, 2006)

Ok, here is the deal, I have been a hobby TIG welder for about 3 years now, passed a couple tests on welding in high school (set the curve for the entire 9 week class in two weeks) And I want to start practicing on some frame size tubing. Here's my question.

-I have a Lincoln stick welder, that I have converted to a tig welder using a valved torch, argon regulator.... blah blah blah, Its set up. I can lay down a darn good bead around some 1/8th" tubing, but have never really tried anything thinner. So, instead of buying a new welder with a high frequency start/pedal, Think it would be alright to use just a lift arc tig until I can afford something better? Or am i going to have a hard time with thinner stuff. I can dial my amperage from 10-135...
I would just go out and try it, but I live three hours away from home (college) and my current living situation does not have access to a 220v outlet. 
Thanks in advance


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## kampgnar (Apr 13, 2007)

Why not? Tig'ing with scratch start will teach/force you how to read the puddle in a vulnerable state. Meaning you'll have to control the puddle with speed, torch angle/distance, and filler deposition rate. 

Maybe order a few feet of 4130 and practice mitering some joints while you wait for the next visit home. You'll have a bunch of fitted joints to see if scratch start will work for you. 

Scratch start isn't the cleanest or most preferable, but I've always "run what I brung". I'd much rather scratch start from a buzz box than have nothing at all and need it.


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## mhmacw (Mar 16, 2010)

Scratch is not bad...! Lift arc tig is widely used in pressure vessles and other exacting specifications. If the parameters are set correctly and the pressure on your shielding gas is right all impurities from the scratch will be burned off. The key here will be practice as to going from thick to tin foil walls. As stated earlier...just go for it ! Jesse James 1997" If you wanna know how to build ****...you gotta build ****" great advice man. Practice will make perfect. I'd give you a laundry list of welding certs I've had but the last one expired in 1993 I think (I'd have to look it up haha). Trust me (and kampgnar) on this one ok. Youll be fine with liftarc.


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## HomeGrownSS (Jan 18, 2006)

guys, i dont know the slightest thing about TIG, or arc welding in general. could someone explain what scratch start/lift arc means? and what the alternative is?


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## Mr.SBC (Dec 18, 2006)

Most Tig welders have a foot pedal to control the amperage. (Kind of like a gas pedal on a car) But, you can get away with buying a used stick welder, buy about $200 worth of parts and you can have a working tig welder for under $400. 

Scratch start means that there is no pedal. You literally "scratch" the tungsten to the metal work piece to strike the arc. You also have to control your gas flow manually with a small valve located on the torch.


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## HomeGrownSS (Jan 18, 2006)

thanks for the explanation.


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## mattty (Feb 26, 2009)

You could probably find some way of making a pedal/button mounted kill switch to kill the arc but still have some post flow to keep the puddle from scaling over. I made about five frames with a scratch arc, and the most frustrating thing was cleaning up the weld to run another bead... this made me more inclined to make an excessively long(too hot) bead. I also had too low of an argon flow as a beginner, I now run 30cfh and a backpurge of ~5. 

Some other tips:

Dont run too small of a cup, to small restricts the coverage and creates bubbles. I now run a #6...

Cleaning scale off while the weld is cooling is a bad idea... as is blowing on the weld to cool it faster. 

Use the rods recommended by aircraftspruce.com , they had a good description for what I needed...


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## customfab (Jun 8, 2008)

it all comes down to the operator, might as well give it a whirl. 

you can probably retrofit your old machine to accommodate a high frequency start module though, might be something to look into.


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## mhmacw (Mar 16, 2010)

That device is called a freq box. It can be attached to any inverter or dc source. Its designed specifically to allow foot/rheostat controlled arc delivery on a source not originally equipped with one. some of the better/more expensive models will also have provision for gas regulator control. Both pre and post flow.


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## D.F.L. (Jan 3, 2004)

Sounds like the full-rigid, fixie version of TIG welding.

A few mitered scraps should answer all your questions.

I can see having no hi-freq start, but no pedal? Ugh.


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## Mr.SBC (Dec 18, 2006)

So, how much does one of these freq boxes run? Although, Ill probably just run what I brung.


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## 858Rider (Jul 4, 2010)

ive been a welder for 10 years now and if you want to build a good product you need to get a tig with HF trust me and a foot pedal so you can feather your starts and stops!


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## Mr.SBC (Dec 18, 2006)

> ive been a welder for 10 years now and if you want to build a good product you need to get a tig with HF trust me and a foot pedal so you can feather your starts and stops!


Im not trying to build the next Indy Fab here, and will certainly not be selling these for buku bucks. I was just making sure I could weld on thin stuff without having a "soft" start feature. If it burns the metal together, and holds the heavy abuse that I throw at it, its fine with me.

Why should I go out and spend ~$800 on a USED tig welder, when I already have one, and I can lay down a beautiful, fully penetrated bead? Unless you will pay for it


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## mhmacw (Mar 16, 2010)

Last I checked (and its been a while) there wasn't really and advantage to a freq box until you get into the 5k plus inverters. Until then its almost cheaper. and certainly more efficient to get a hi frequency or squarewave welder. All in all man if your not building for anybody but yourself and you trust your welding skills... keep what you got and be happy. Lift arc will do fine until your talkin .020 titanium or something totally outlandish. Don't be sucked in to someone else telling you what you have isn't good enough.


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## mhmacw (Mar 16, 2010)

858Rider said:


> ive been a welder for 10 years now and if you want to build a good product you need to get a tig with HF trust me and a foot pedal so you can feather your starts and stops!


B.S.!!! Lift arc has been around for decades. Anybody worth their salt can weld just as good with lift arc as they can with hifreq control.:nono:


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## shovelon (Mar 16, 2006)

mhmacw said:


> B.S.!!! Lift arc has been around for decades. Anybody worth their salt can weld just as good with lift arc as they can with hifreq control.:nono:


What he said.


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## DEFCON4130 (Dec 19, 2009)

Mr.SBC said:


> Ok, here is the deal, I have been a hobby TIG welder for about 3 years now, passed a couple tests on welding in high school (set the curve for the entire 9 week class in two weeks) And I want to start practicing on some frame size tubing. Here's my question.
> 
> -I have a Lincoln stick welder, that I have converted to a tig welder using a valved torch, argon regulator.... blah blah blah, Its set up. I can lay down a darn good bead around some 1/8th" tubing, but have never really tried anything thinner. So, instead of buying a new welder with a high frequency start/pedal, Think it would be alright to use just a lift arc tig until I can afford something better? Or am i going to have a hard time with thinner stuff. I can dial my amperage from 10-135...
> I would just go out and try it, but I live three hours away from home (college) and my current living situation does not have access to a 220v outlet.
> Thanks in advance


Id say you can totally do it. Id mess around with it while you save for something better tho.

Ive never done what you doing setup wise but.. one thing id worry about is how stable the arc will be at the lower amperage (running 110v is not helping.. 220v is smoother.. 440v=king) so you can really focus the arc in the joint. If you can start your arc on the thicker side of the joint like HT not TT.. help keeping arc start popping holes on the thinner tube when the arc opens and stabilizes. You can do without HF... for me the biggest obstacle would be not having a pedal to control the heat.

Also not sure scratch start and lift arc as the same thing. I always thought lift arc was with the pedal and scratch start was with no pedal. Thank god i never have to worry about that.


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## shovelon (Mar 16, 2006)

Lift start is a whole lot different than scratch start. Lift start does not activate the arc until a ground sensing circuit is broken, that allows the start circuit to activate. Scratch start is same for tungsten electrode as well as shielded metal arc electrode(stick), start circuit and upslope does not initiate until ground is sensed.

Whatever lift or stick, generally you are limited to panel heat adjustments(non remote).


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## bobbotron (Nov 28, 2007)

shovelon said:


> What he said.


Heh, where do you guys find this stuff?


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## shovelon (Mar 16, 2006)

bobbotron said:


> Heh, where do you guys find this stuff?











He He, I'll never tell.

(Hint, GARGLE)


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