[kaighn80]

right untill i get any good at this tig welding malarky im not going to even consider aluminininium, so i got a dc stick welder and my main ideas are to buy
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT one of them and
http://cgi.ebay.co.uk/Mig-Welding-Ga...item483a894693 one of them and one of these
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT

or would i be better getting one of these http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT

if i do buy the solenoid then does anyone know of a pcb diagram that i could put a pot onto so the gas solenoid stays on for a variable ammount of time after the weld has stopped to cool the work?

also im thinking of putting a car starter solenoid inline with the power lead so its not on all the time is this something that is feasable or do i just need to be a bit careful when i put the torch down?

also eventually i would like to go hf start so any info on that would be greatly appreciated.

oh the stick welder is a giant mma 200amp

[underthetire]

You'll still need a reg assembly, and be able to really dial down the welder for most TIG stuff. IMO just dump the stick welder, and buy a TIG, even if it's just the HF one. Hell they even have a digital unit for about 300 US.

[kaighn80]

You'll still need a reg assembly, and be able to really dial down the welder for most TIG stuff. IMO just dump the stick welder, and buy a TIG, even if it's just the HF one. Hell they even have a digital unit for about 300 US.

thing is if i had 300 usd i would buy one but im in the uk and a ****e tig costs the earth here, so far ive been given a mig welder and arc welder, the mig came with gas bottle and regulator so im not that worried about using it for the home made tig, but money has to be kept to a minimum. the mig is an sip handy mig 130 which is shocking, its that old that after about 3-4mins flat out it will over heat and shut down, so i installed a 12v trans and a motorcycle radfan now i get about 20mins flat out before it shuts down, but because its not that powerful im not getting very good penetration on anything above 1.5mm thick and even then im working really hard. the stick welder has come in handy with letting me build a motorbike chassis jig but to build a chassis i need something a bit neater. im looking at a hf starter circuit at the moment from here

http://www3.telus.net/public/a5a2631...bARC_START.pdf

might be something i will use later on, im thinking of building a replica of this one and i could build it bit by bit till im either in a position to either finish it in one go or ive got all the bits built.

[neilw20]

Try to understand the process, so you don't just waste what little money you have.

http://en.wikipedia.org/wiki/Gas_tungsten_arc_welding

You either need special current controlled low voltage to start the arc or a pilot arc system.

Just scratching the tungsten rod to start the arc will contaminate both the stick and the job and is undesirable.

AC is mostly used with TIG welding to prevent transfer of tungsten to the job.

Spend the money, or just use a normal stick.
Just because you have a holder and a stick welder does not mean it will work well, if at all.

All that sparks is not weld, let alone glitters like gold.

[kaighn80]

yeah great thanks for the help think i'll go with just bashing one together and working everything else out later as this forum is no help what so ever unless you want the advice "go spend a load of money on crap that does the same job", im not being funny but im still waiting for anyone to actually answer my questions rather than telling me it cant be done when i know that not only is it possible but its done by loads of other people with worse equipment than i have, after all why would companys sell the conversion bits if you couldn't do the conversion?????? if you dont have an answer to the questions ive asked or a solution along those lines dont waste my time. :argue:

[Kipper]

I converted a 100A Clarke type mig around 20 years ago for a mate.....I think he's still using it!

The gas valve is essential...as is fitting a post flow capacitor.

Perfectly feasible to use scratch start for welding steels.......It's a bit of a "Nike" situation.... Just do it.

[kaighn80]

I converted a 100A Clarke type mig around 20 years ago for a mate.....I think he's still using it!

The gas valve is essential...as is fitting a post flow capacitor.

Perfectly feasible to use scratch start for welding steels.......It's a bit of a "Nike" situation.... Just do it.

thanks kipper, dont suppose you know of a circuit design for the gas control that would allow it to be adjustable? im still toying with the idea of a starter motor solenoid as an on/off switch for the main power, im looking at hooking it up on the trigger of the torch.

this is the hf start diagram im going to use.

http://i443.photobucket.com/albums/q...sparkstart.jpg

[Kipper]

Have a look at 555 timer circuits for the gas control (I kept it simple with a capacitor providing post flow while the cap discharged)

A starter solenoid would "do my cherries in" switch the 240V input and use a lower current carrying relay :idea: Quieter?

[gmfoster]

Try to understand the process, so you don't just waste what little money you have.

http://en.wikipedia.org/wiki/Gas_tungsten_arc_welding

You either need special current controlled low voltage to start the arc or a pilot arc system.

Just scratching the tungsten rod to start the arc will contaminate both the stick and the job and is undesirable.

AC is mostly used with TIG welding to prevent transfer of tungsten to the job.

Spend the money, or just use a normal stick.
Just because you have a holder and a stick welder does not mean it will work well, if at all.

All that sparks is not weld, let alone glitters like gold.

Scratch start was used for years and while not the best is certainly usable in many applications..

Even you reference says so...

[kaighn80]

Have a look at 555 timer circuits for the gas control (I kept it simple with a capacitor providing post flow while the cap discharged)

A starter solenoid would "do my cherries in" switch the 240V input and use a lower current carrying relay :idea: Quieter?

get on your nerves i take it? i was thinking of using one off a classic mini as i get them cheap, the only noise they make is when they make the initial contact and even then it just clicks and thats it, also itsopperated by 12v which would be safe for the trigger and gas solenoid forgot that the guy who has a workshop next to mine installs nos so i might be able to get a used solenoid off him cheap which will also run on 12v.

Scratch start was used for years and while not the best is certainly usable in many applications..

im going to build a hf start circuit asap so i shouldnt have to scratch start for very long.

[kaighn80]

just found this for the gas delay

http://www.aaroncake.net/circuits/relaytim.asp

so now i need a few bits and i can make a start im looking at a couple of transformers for te arc start any suggestions?

[snoeproe]

X Ray quality tig welds are made daily in industry with scratch start tig.
Infact, DC scratch start tig welding is my prefered method for welding stainless steel pipe. I am currently certified with the TSSA here in Canada for welding stainless pressure pipe with tig and carbon steel pressure pipe with stick.
If you just want to tig weld carbon steel and stainless steel, scratch start with a dc stick welder is the way to go. Cheap and very effective.
All you need is a bottle of argon, a regulator/flow meter and a tig torch with a manual gas valve on it.

[snoeproe]

Guys, there has been alot of very missleading information posted in this thread that will confuse (not help) the original thread poster.

neilw20 posted that scratching the tungsten to start will contanimate the weld with tungsten. This is true somewhat if you are using the incorrect tungsten and don't know what your doing. neil also posted that most tig welding is done with AC to prevent tungsten transfer to the weld. That is very untrue. AC is only used to tig weld aluminum but you need high frequency to start the arc without touching your tungsten to the work. DC- polarity is used for tig welding carbon steel and stainless steel. Most DC tig welding is done with either lift start or scratch start in industry. High frequency can be used to tig weld with dc but it is just used to start the arc, not through the entire weld job.

Kipper posted that he converted a Clarke type mig welder to weld with tig. This is interesting because all mig welders are constant voltage powersources. Tig and stick welders are constant current powersources. Using a constant voltage powersource for tig welding will not yield good welding results.

I'm not saying that I'm an expert welder but I do weld for a living in a heavy industrial environment.