gpigeon 7th June 2007, 09:17 PM This is my first time on this forum so please "be gentle" with me. I have a question for all you welding experts.
I am occasionally wanting to weld thin stainless (and maybe aluminium) sheet so require a tig welding m/c. However, I baulk at the high price of the new machines.
What is so special about a TIG welder apart from the handpiece and Gas feed system and the $1000 plus price tag. Why can't a tig handpiece + argon regulator etc be fitted to an ordinary 240V single phase welder?
Alternatively, I have an old (perhaps ancient - but still working well) 3 phase motor driven DC welder. The one I'm sure some of you older guys will be familiar with....a 3 ph motor sitting on top of a large retangular box with both voltage & current control dials on it. Can this be used for tig welding if the appropriate handpiece is fitted?
Thanks for your help.
Bill.
Bondy1s 7th June 2007, 09:53 PM Hello gpigeon and welcome.
If you are referring to the old style lincoln "bullet" DC welder, you can use this as a power source for a tig. You need to get hold of a high frequency unit and the tig torch, leads, reg, etc. Most welder supply specialists can supply these units and show you how to connect it all together. The old bullet welders are very reliable and produce a stable output and many are still in service today.
Bondy.
DJ’s Timber 7th June 2007, 09:58 PM The old DC welder that you are talking about is what I learnt on when I did my apprenticeship, use it as a Tig for stainless steel. They are a great welder.
Problem is you need to have +/- AC for Aluminum, which is why Tigs are generally expensive.
Wait for Graham to come along, he will be able to explain better
Grahame Collins 7th June 2007, 10:46 PM Hi gpidgeon and welcome to our forum.
With TIG it gets back to what you wish to weld.
Unless you have a lot of dollars you will find the the cost of an AC DC tig a stretch. Around $5000 to do both Aluminium and tig.Tig on stainless steel and then want to change over to aluminium ,you will need different gas. $$$$
If you must have both AC/DC consider a second hand unit.If you have 3 phase ,its possible to pick up a bargain.
Tig is a lot harder than stick or mig and is more compatible with the techniques used in oxy welding.
If you are a good oxy welder you probably will do well with tig.
Finally stick with well known industry brands. You get a history,good reputation and spare parts. E bay is not the place to buy your welder TIG or otherwise.
To answer your question about rigging a AC welder.It can be done if you can find a HF unit but you are still limited to aluminium.No High Frequency no welding aluminium as its needed to stabilise the arc and clean the aluminium.Setting up on a the 3 pH DC machine you mention,while it will work technically,it could be likened to cracking a peanut with a sledgehammer.Most Tigs operate in a lower amps range, say to 170 amps.Your bullet welder will be capable of possibly 300 amps depending on its capacity.
hope it all helps
Grahame
browny 8th June 2007, 08:52 AM A few comments from a tig newby....
I bought an ebay DC pulse inverter tig for around $740. The seller seems to support his products, is local(ish), offers a warranty and has a shopfront. It seems to work fine. Certainly it is me that is the weak link rather than the machine. I would be more than happy to buy other products from him.
If I didn't get an ebay tig I would have either bought nothing or ended up with a really basic name brand inverter (which I found out the hard way are basically throw away if anything goes wrong, ie might as well buy a new one because of parts cost).
The machine is only part of the cost. Regulator/flowmeter ($200), tungsten ($50), gloves, stainless wire brush, argon ($110+$120 rental), filler all add up.
The decision to weld aluminium is a big one. AC tig is a lot more expensive - roughly double for the machines I was looking at.
I much prefer it over mig. Almost silent, no spatter, no smoke, slower and more controllable, easier to see the weld pool. The downside - slower, tig needs everything to be clean and well prepped so you cant cut corners like mig (which is IMO a good thing as it is forcing you to be a better welder), more expensive consumables, requires a steady hand, more difficult when welding out of position.
Vernonv 8th June 2007, 02:50 PM Browny,
What is the brand name and/or model of the unit you got?
Have you used it much?
gpigeon 8th June 2007, 07:19 PM Gentlemen,
Thanks for your help. It has cleared things up a bit. The "bullet" seems to be a very good description of the old m/c I have. I remember the welders dragging these units around the site on their 3 wheels when I was an apprentice (Fitting & mach) in the 60's. I haven't actually used this one yet but it does run.
Seeing that I already have a tig handpiece & reg (had them for 30 yrs and never used them) I think i will follow your suggestions and try to fit them to the Lincoln.
For the occasional use that I would have for this welder I doubt if it would be worthwhile hiring the argon cylinders. I think I have seen mentioned some "disposable cylinders". Have any of you got comments on these?
Interesting forum and dedicated contributors! Keep up the good work.
Regards.
Bill
browny 8th June 2007, 07:29 PM Vernonv
It's a tokentools 200A tig (200P?)
I have only just started, probably only used half a dozen rods of filler.
Do your sums on the disposable cylinders. For reference an E size cylinder is ~$110 + $120 p.a. container hire and holds 4.1m3.
The little disposable things look like they hold SFA and I reckon the $/m3 of gas will be right up there.
Stringy 8th June 2007, 09:13 PM Bill,
Just a couple of comments;
Gas for TIG, Stainless, Carbon Steel and Aluminium can all use the same gas ie; straight Argon.
When connecting your leads;
Handpiece to -ve.
Work clamp to +ve.
Thoriated tungstens are the norm for carbon and stainless, zirconiated for Al, but due to the radioactivity of thorium many companies around this area have changed over to Cerriated tungstens which can be used on both.
Keep your eyes out for a seperate High Frequency unit as there should be some about which are not used anymore (havn't seen one used for years), they plug into 240v seperate to the welder.
Good luck, those bullets with the adjustable voltage ran a nice arc in their time and were used widely for TIG:2tsup: .
simso 11th June 2007, 10:27 PM Exactly as everyone else has already said. You can get cheap tig units of ebay and they are exactly as youve described regarding the conversion of a standard dc arc welder. The big difference and hence price jump is the ac adaption for aluminium, then the [price goes up regarding whether you want little fione adjustments like foot control of amperaage, ability to bias the ac arc for cleaning to weld penetration, soft start with ramp up, ramp down capability, crater fill capabilty, squaare wave welding instead of sine wave ect ect ect. Its all the little fancy things that make life easier when welding but also increase the price. For standard welding of steel and staainless in thin materials up to say 4mm a cheap ebay unit will more than satisfy
Steve
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