Buying A Welder

[matho]

Ac is used for tig welding aluminium

 

[mayzi]

I know I will trip up here and someone who knows more will point out where I'm wrong, but running off the top of my head with AC V DC, (you are really starting to look into some very complex welding/electrical theory with this.) AC = alternating current = polarity switches constantly at a very high speed which is referred to as hertz. This speed and electrical wave can be controlled and you can control where and for how long the 'heat' of the weld is, either in the stick or in the job. DC = Direct current and polarity does not switch, you can still control where the heat of the weld by reversing the polarity, but in general not to such a high degree as in AC. But do you need to know this as a home/hobby welder? No (the same with brewing a beer really ie how much do we need to know about chemistry to make beer). Theory aside (I haven't really touched on much of it, I'm sure Wikipedia/google would have info if you are interested in finding out more, feel free to ask more if you want.) with AC you can weld nickel and magnetic plate. As a general rule AC requires higher current for the same electrode. You can tweak AC settings for finer tuning for very specific jobs. DC is considered inherently safer and easier to use. Most stick welding is done in DC. DC is quieter, which after awhile does count. Thats pretty much a quick run down, but really for what you want I don't think you will need to be concerned with AC and DC will be more than adequate for you needs.

 

[Ducatiboy stu]

Ac is used for tig welding aluminium

When I can weld Ally, I wont be needing to ask any more questions :icon_cheers:

 

[Ducatiboy stu]

I know I will trip up here and someone who knows more will point out where I'm wrong, but running off the top of my head with AC V DC, (you are really starting to look into some very complex welding/electrical theory with this.) AC = alternating current = polarity switches constantly at a very high speed which is referred to as hertz. This speed and electrical wave can be controlled and you can control where and for how long the 'heat' of the weld is, either in the stick or in the job. DC = Direct current and polarity does not switch, you can still control where the heat of the weld by reversing the polarity, but in general not to such a high degree as in AC. But do you need to know this as a home/hobby welder? No (the same with brewing a beer really ie how much do we need to know about chemistry to make beer). Theory aside (I haven't really touched on much of it, I'm sure Wikipedia/google would have info if you are interested in finding out more, feel free to ask more if you want.) with AC you can weld nickel and magnetic plate. As a general rule AC requires higher current for the same electrode. You can tweak AC settings for finer tuning for very specific jobs. DC is considered inherently safer and easier to use. Most stick welding is done in DC. DC is quieter, which after awhile does count. Thats pretty much a quick run down, but really for what you want I don't think you will need to be concerned with AC and DC will be more than adequate for you needs.

Being a sparky/tech I know exactly what AC and DC is....But I didnt know there was a difference in the way they coud be used for welding.

Sounds like DC is good enough for me

 

[Ducatiboy stu]

Went to Gasweld today and found a few nice welders.

The ones that where was recomended where these Mig only

https://www.gasweld.com.au/products/580026
or

https://www.gasweld.com.au/products/580095
or

https://www.gasweld.com.au/products/580027

They all had better quality hand pieces and better ratings than the ones $100 cheaper

As for stick welders

https://www.gasweld.com.au/products/580020

Sales guy told me it has been tested at 15 rods per hour for 24hrs, its an older more robust design, simple and bullet proof

Looks like it might be cheaper to get seperate welders

:unsure:

 

[komodo]

Tweco handpieces are nice bits of kit. We've seen a drop in RSI on trigger finger for our welders in my shop since we changed to them. (We burn about a tonne of wire a month - so you can imagine thats quite a bit of "on" time so RSI is relatively common.)
In the shop I run a mixture of welders for the boilies and big mofo WIA units for the welders. The boilies all seem to preffer the Kempi MIGs to the WIA and lincons (the lincons are a PITA cause the trigger wire for the hand piece pulls out of the wire feed. It was better in the old shop as we had the wire feeds over head on swinging booms - cant really do that in this shop because of the 2T swing arm work bench crane hoists). The WIA units the welders use are indestructable I think I've only ever replaced a wire feed on one in the past 6 years.
For farm use honestly Kempi inverter ARC you'll never look back. No faffing around with gas. Nothing to go wrong in the hand piece (decent hand pieces for MIG are exy) and you can run them off a 3-4kVa generator no worries - infact from memory the newer units have a seperate generator input. You can burn rods with them all day (my site boys quite litterally do at times we buy a tonne of rods every 1/4) no worries about gas (and wind) or moving parts. My boys have dropped them out of the bucket and they get thrown around all the time. I have a spare unit we sometimes lend to the riggers and they are dynamite on tools - they distroy everything (including my booms and scissors!). But the Kempi bounces back and usually repairs are simple and cost effective.
Now admittedly 6mm is about where we "start" as far as material thickness is concerned but I have seen the boys weld some real thin material (down to 1.6mm) and I'm pretty sure you can get DC TIG kits for them if you want to play with the smaller flame.

If you are going for a MIG watch cheaper units - often they only take the smaller spools of wire which work out to be a bloody expencive way of buying wire
Mig is great in a workshop no wind etc. But they are noisier compared to stick. They are more maintenance. Decent units are more expencive. Less portable. If you can afford both then thats the way forward. But if I was buying one or the other - it would definately be stick. Remember stick can get into places you cant get with a mig hand piece cause you can bend rods to get in behind a plate etc. We have an old stick unit in the workshop purely for this reason - and you'd be supprised how often its used.

 

[Ducatiboy stu]

The bloke in the shop warned me about the small spools, he said that becasue they have a small spool radius as you get towards the end the wire starts to coil up like a spring coming out of the handpeice.

Prob get a mig first, as I mainly will be doing tubes, angle, flat etc, nothing overly complex.

 

[mayzi]

Good luck with it which ever way you go. If you haven't done too much before grab someone who knows what they are doing to show you the ropes. It will save you a lot of heart ache than trying to work it out yourself. Other than that its down to practice and a few kilos of wire/rods and you'll go fine.

 

[Zizzle]

2 pages... jeez... grow a pair, man up and make a decision already VespaboyStu.

Ok, now serious...

I got a used WIA from the classifieds a few years ago. $300. It was a bit beat up but I rebuilt a very rusty car with it... and it hardly missed a beat.

I also made up a little bracket to hold the little spools. Not as smooth as the big ones, but lets you have few different wires on hand... and a sometimes it's good to be able to run to Bunnings or supercheap on a sunday and get some MIG wire to keep you going.

 

[Ducatiboy stu]

Spoke to my neighbour, and he suggested getting a MIG that will do 10mm... as he is a boilermaker....

I aksed him what welder he has ATM...

yeah, I have an inverter welder, I suggest you buy an old fashioned transformer welder , they are better.