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MIG/TIG welding

Posted: Mon Nov 19, 2007 10:30 am
by Blitzkrieg
Which of these two types of welding is better?

Anyone know how much one of these machines costs?

Posted: Mon Nov 19, 2007 11:11 am
by Chris
Phone Lincoln welding in Silverton,and speak to those guys.They are good at what they do!They also sell welding equipment at good prices.

Posted: Mon Nov 19, 2007 11:18 am
by Blitzkrieg
Thanks, will do :wink:

Anyone else want to chip in?

Posted: Mon Nov 19, 2007 12:21 pm
by Bad Ass Bob
Mig welding is the type exhust shops use it has a wire feed out of the gun Tig welding is for stainless and ali were you use a rod for the specific type of material you are welding, hope this is enough to you going B.A.B

Posted: Mon Nov 19, 2007 3:09 pm
by lowlight
With MIG you have a whole role of wire. To weld different kinds of metal i think TIG is better, cause you frrd rods by hand.

MIG/TIG WELDING

Posted: Mon Nov 19, 2007 3:10 pm
by BARON
Hi Blitz,
The problem with both processes are that the volume x pressure of the bottles classify them as dangerous to use just like big oxy/accetelene sets so the bottles need to be registered to a owner and need to be inspected and certified as safe for further use on a regular basis. Thats why you never buy the bottles---only the content--- because Afrox or whoever stays legaly responsible for them. Small oxy/accetelene sets falls outside the volume x pressure cut of point so they are ok. (Ocupational and Health ACT )
So if you buy a big bottle from any one be assure its illegal.
You theoretically only rent the bottle and buy the content.
The rent is so high that it is not viable to go for any of these options unless you can make some money out of your welding.

The main difference between the two processes are;-
TIG produces a small area high concentration heat spot as against MIG with a lower heat imput wider area.
TIG will give you a deep penetration weld ie use for thick through thickness welds-- where MIG give a shallow penetration good for thin wall plate type materials.(les distortion)
Because TIG is a manual process the high heat distortion can be controled by stich welding or a lot of stop starts.

So------ both techniques can be learned, with TIG maybe easier because you determine the pace as you wish where MIG maybe more tricky --more variables to control at same time( settings on equipment need to be spot on)
For plate metal work MIG is the one but to have both would be very nice.

cheers
Baron

Posted: Mon Nov 19, 2007 3:23 pm
by Blitzkrieg
Thanks Baron :D

I'm still trying to get prices on the machines :?

Posted: Mon Nov 19, 2007 4:42 pm
by Bad Ass Bob
Contact Cromwell they have in there new 07-09 cataloge http://www.cromwell.co.za +- R3500 and it has small gas canisters B.A.B

Posted: Mon Nov 19, 2007 7:34 pm
by IMPI
I own a mig made by SIP in the uk at the time I bought it it was the cheapest mig in sa (se ad in car mag) it uses .6mm wire which is ideal for body work.
Tig welders need an absolutely clean surface for welds of good quality. this is not really possible on old car bodies. I dream of a tig but for welding heads etc.
The next easiest to use is oxy acetalene but too much heat causes warpage and is not reallly suitable for large flat panels such as doors etc.

Posted: Tue Nov 20, 2007 9:50 pm
by Riftvalleyvw
If you plan on welding much Aluminum or Stainless, then TIG is the way to go. If you will be doing body work and steel like sheet metal and angle iron a 180 amp MIG welder is best. With the MIG welder you can also use what is called Flux Core wire. Lincolns is 211-MP. With this wire you dont need to use gas. It is the same type of wire that Professional welders use for building construction except they use bigger wire with a little different flux and more powerfull machines. You can find the MIG welders pretty cheap sometimes but you are better off with a Name brand like Lincoln or Miller. They will always have the consumable parts that are necessary. A Mig welder will be your best bet for youe VW work. I dont know what your voltage is but usually they are either 115 or 220 volts. Sometimes 370. If you have the 220 volt available at your house or shop, it is the best choice.

Posted: Tue Nov 20, 2007 10:02 pm
by Chris
SA is using 220V.

And yes you are right about Lincln.The branch in Silverton carries a whole range,and there back-up service is very good.

Posted: Tue Nov 20, 2007 10:06 pm
by Riftvalleyvw
Good then it should not cost so much. In ethiopia ist is supposed to be 220 but.... some times I even measured it at 165... I have some inverter welders that will auto adjust to different voltages and they refuse to work in Ethiopia....

Posted: Wed Nov 21, 2007 2:27 am
by ZeroAxe
Ok here is my take on it. And if I step on any toes, dont be offended. It is not personal.... I am purely commenting on the quotes because I personally feel they are not 100% correct

I have been working with MIG welders for over a year now, 9hrs a day(excluding hours put in at home on my welder). I have to disagree with Baron:
TIG will give you a deep penetration weld ie use for thick through thickness welds--
I would challenge ANYONE out there to show me just how easy it is to go and weld a 10mm plate with a TIG welder. Not that it cant be done, it is just going to take a LOT of effort/work and time. TIG welding needs a CLEAN, prepped area to weld. WIth a 10mm plate for example, you would need SEVERAL passes with a TIG welder to do a proper weld. And each time you do a pass, the heat(weld) would heat up the metal and bring out some of the natural 'impurities' in the metal.

where MIG give a shallow penetration good for thin wall plate type materials.(les distortion)
Contrary, MIG welding is used for THICK plates/metal. It is all in the way that the welding seem is prepped. However, on thick plates, several passes ALSO needs to be made with a MIG welder. At my work, we build big conveyor belts, and the chassis of these things often have metal in the region of 15-20mm. This is all MIG welded. On the other hand, with a decent MIG welder, properly adjusted, can successfully be used in sheet metal work. I.e. welding in new panels on your restoration project.
Because TIG is a manual process the high heat distortion can be controled by stich welding or a lot of stop starts.
This comment is correct.
So------ both techniques can be learned, with TIG maybe easier because you determine the pace as you wish
Incorrect. To do PROPER TIG welds, it takes a LOT of time and practice, and above all, PATIENCE. To get good penetration and a strong weld, you need to KNOW your machine well, and how to control it.
where MIG maybe more tricky --more variables to control at same time( settings on equipment need to be spot on)
Again I disagree. Although the settings does need to be spot on, MIG welding is easy to learn. I would say that anyone that has got some DIY talent, can learn in a day how to do decent, clean and proper MIG welds. By no means would it always be 100% spot on, but you would be able to do good welds.
For plate metal work MIG is the one but to have both would be very nice.
I would again say, for metal work that TIG is the one to have. But I agree, I would LOVE to have both. But the cost of a TIG welder prevents me from owning one(at least for now). It also has got draw backs, for example, you cant weld your new panels AND build a new fence for your garden with it, like you can do with a MIG welder!! (well, obviously you can, but it would be crawy to use a TIG welder to build a 30m fence with!!! :roll: )


With a TIG welder, you do precision welding. Like HotRod chassis, aliminium heads, Stainless exhaust pipes, aliminium bicycle frames and the like. MIG welders is for 'bulk' work, but also sheet metal work. The biggest difference between TIG and MIG welding with regards to sheet metal work, is the 'flexibility' of the weld when worked on. With a MIG welder, the weld is harder and more brittle than with a TIG welder. If you weld two sheets with a MIG welder, and work it on an English wheel, or planishing hammer, chances are that the weld would develop a crack somewhere. However, if your TIG weld was not done properly, this would happen as well.

The reason I say that with a TIG welder, you can control your weld(process) MUCH more than with a MIG welder, is because of what I saw Ron Covell does with his TIG welder. And I challange ANYONE out there to make a video of it and send it to me personally(with their MIG welder)!!! Ron took two pieces of aliminium foil(yeah, those you wrap your sarnies in!!!) and seem-welded them together (without a filler rod obviously) with a TIG. It came out as one piece, not a single hole burned!! and to top it off, he tugged on it and it didnt tear! :shock:



Now before I go and lock myself up(before someone comes to tear me a new A-hole), I will give some good advice. STAY AWAY OF THESE MIG WELDERS(see pic below)
Image


Notice those two small white switches? Those are your power settings. THEY SUCK!! Either not hot enough, or too hot. When welding panels, you either dont get decent enough penetration in your welds, OR, you burn a f-ing hole through your panel! TRUST ME, I have one gathering dust..... Then, I got me a decent one....
Image


Here you can fine-tune your power settings vs. wire feed. Also, you got a 'timer' option. What this allows you to do is hold down the trigger to do a spot-weld, and after the preset time(in seconds), it will automatically stop welding. So you can for example set it to do a 5 second spot-weld. Much better machine, with WAY better results. I does come at a price though.

Oh yeah, and before I forget. Just as important... Go the extra stretch and get a contract for a gas bottle (normally Argon/CO2 mixture is used, but ATAL is just as good, and cheaper. BUT, it is not recommended to do S.Steel welding with ATAL gas). Forget that Core Flux wire. It SUCKS, especially when welding sheet metal/new panels on your restoration project!!!!!!



Ok, I think it is enough for now playing MR. I-know-it-all !!! And again, BAron, it is not personal, just my take on it :wink:

Posted: Wed Nov 21, 2007 4:26 am
by Riftvalleyvw
Ohhhh.. You French guys are all the same... You got to remember, this is AFRICA. We dont need no stinking machine... We just plug the cable into the wall and use a coat hanger for an electrode :shock: Welds it right up :D Piece of Cake!


No really now. You are 99% correct in all your statements except the part about fluxcore and the fact that you cant weld 10mm steel with TIG .
TIG (in the right hands) will make absolutly the best welds on all types of metals no mater the thickness. To make bigger welds you need a bigger machine. Many people dont know how to weld big welds and will try to weld 2 pieces of 13mm steel together in one pass. [size=18]WRONG
! BUT! TIG is a precise process. not a quick process. It requires 2 hands. That is why it is mainly a bench process.
For the typical VW guy the best welder is a MIG welder. If your flux core does not make a good weld, it is because YOU cant weld....[/size]
:D

Another problem here in Africa is that we dont necessarly have a SHOP to work in :( Got to work outside or another not quite so desireable place like under the car... :cry: So the gas sheilding wont work worth CACA! Just blows away. And if you are trying to weld something and drink your beer it is very difficult to also hold the part you are welding in place......
One of these days I will figure out how to write and put photos here :party:

MIG/TIG

Posted: Wed Nov 21, 2007 6:50 am
by BARON
Hi all,
No offence taken Zero.
The more info we can give the guy the better choice he can make. I agree and disagree with you but lets not go there we are going to highjack the subject.
My statement on penetration dept is based on laboraty samples of weld specimens I see from time to time.
Blitz Im sorry Idid not mention the flux core option, its new technollogy and not known by most by home welders and I dont know how practical it will be ,but its expensive --can be your way out of the bottle situation though.
Dont ignore the oxy/accetalene option---very cheap and very simple to use. The down side --lots of heat distortion ,but that was all the older generation had and with a lot of patoins they build nice cars. JUST CONTROL THE HEAT.
Riftvalleyve you said:- I have some inverter welders that will auto adjust to different voltages and they refuse to work in Ethiopia...well we have the same problem in SA, they allways want more money for less work

cheers
baron