[nervis1]

I need a TIG machine. 1/4 inch max will be my envelope, mostly AL so I'd like square wave, no need for water cooling, I have a 60 amp 240V circut but I'd like to be able to run from 110V if needed (I know some of the Millers will do this). Anyone have a specific model to recommend?

[ESjaavik]

You should consider renting one first.
Welding aluminum is very different from steel, so you may not know your priorities until tried. For one, I think you will want water cooling for 1/4", and lots of current. If price is a concern, look for an old industrial unit. They have now come down in size/weight quite considerably, with many automatic features, and many businesses want these new units (and can afford them). So if you have space, you may get a good one for a fair price.

[nervis1]

About how many amps would I need to do 1/4"? I'm using this in a garage so that may be a limiting factor.

[an0n]

I would say 250 - 300 amps since welding alu really takes lots of current

[nervis1]

Well looks like that idea is out the door LOL.

[nervis1]

I just ordered a Miller Dynasty SD with the torch kit from Cyberweld. I stopped by a local weld supply place and they told me it will do just about anything only limited by my circut. They did say that with 1/4" I'll need a water cooled torch like was stated above. Maybe later. Their price as 1k higher than the internet, I wanted to buy local but that was just too much!

I'll let you all know how it works, and even better how it is on a noob like me.

[an0n]

Very nice, I havent tried any Miller unit, What kind of amerpage does it have at max?

[nervis1]

http://store.cyberweld.com/mildyn200sda.html

Heres the link.

Says 1-200

I'll just have to adjust my projects to fit as I just don't have the current, or space for a bigger unit.

[an0n]

that seems like a very nice unit, and the price was awesome
it'll be fun to hear how it is to weld with..
Try welding some normal iron first, and getting the feel for adding filler rod, and when you are starting to get the coordination right then move to welding alu..
remember to clean the alu before you weld otherwise it'll be really really hard to get any good looking welds ^_^
Good luck, I am looking forward to hearing about your progress

[ty1295]

I have had a miller 180sd for 3 years now. Used the piss out of it, works great.

Even welded up to 1/2" thick aluminum once, although preheating is a must.

I wouldn't have an issue doing 1/4", now if you said you needed 10ft of weld done at one shot, the air torch aint going to cut it. You would want to stop and let it cool. I have had the torch hot enough even gloves didn't help much.

You will need 70 amp breaker for the 180sd though, or be very careful in your max setting.

Aluminum is the worst to weld in terms of power requirements, so just be aware of that.

[nervis1]

http://www.millerwelds.com/education...es/story71.php

Draws 16 amps 230 at full tilt? Cool. (third to the last paragraph).

[ESjaavik]

I didn't see it having slope up/down control. Then you should have remote control Foot pedal. Or do as I did and make a control knob mounted on the handpiece. It's just a potentiometer.
If you don't slope down, there will be a crater at the end of the weld.

[lesd]

I have a miller 180, and I do a lot of AL with it. If the work you are welding is big *and* 1/2 thick, you will need 250+ to get it all hot enough. If it's not as massive, say a couple of smaller 1/2" parts welded together, then my 180 can do it. It involves flooring the peddle at max amps. The basic issue is AL conducts heat very well, and the mass of the part sucks the heat away from the joint.
-Les

[nervis1]

I got the contractor kit Miller offers with an air cooled torch, regulator, flow control, some consumables, and a foot pedal. I think a stick holder is in there too.

Lesd

Thanks for the info, I was wondering why aluminum would take so much to weld.

[JEFFY]

Alum is a very good conductor of heat, it just soaks it up like a big magnet to steel.
Anything that is a good electrical conductor will conduct heat, just take a short lenght of wire about 4 to 6 inches long and put the one end in a flame and see how quick the heat runs up the wire to the point that you can not hold it. The better the conductor the quicker the heat moves. Hence the suggestion to preheat
Jeffy

[ViperTX]

Okay, my brother just bought a Miller Synchrowave 180 SD which according to the local Community College Shop teacher is the best minimum effort system. So, you'll need a healthy 220 volt source with a minimum of 50 Amp breakers to go beyond 135 amps on the ouput. The 135 amps was what we were using for welding some crows foot aluminum plate (about 1/8 inch thick) and getting good penetration....hmmmmm....

[ty1295]

I blew a 50 amp and 60 amp breaker both with ease on mine.

I would go for the 70 which I have yet to blow.

The thing about aluminum on top of the tendancy to transfer heat, is you are using AC, so already you are down by 1/2 the power.

[nervis1]

I have a 100A 230 breaker going to my 20 HP 3 phase convertor. I should run in 3ph from that eh?
I could probably rig something up, like two lines coming from the breaker, just run one at a time. I would not be running the CNC at the same time anyway.

[ESjaavik]

@Nervis: From the blurb at the website you pointed to, it seems your machine will adapt to the voltage and take 1ph or 3ph. So it should just be able to connect directly to your 100A 230V. No need to suffer the losses through the 3ph converter.

Disclaimer: I only go by the info on the webpage, so you better check it can be connected to 230V, 100A, 1Ph to be sure. You will be running 100A through just 2 rectifier legs instead of all 3, it may not be rated for this.

And 100A 230V would probably be an overload for your converter. Does'nt matter for your welding machine though, as the load will not be continous.

[ViperTX]

So, just a cautionary note: Make sure that the wiring will handle the current of whatever breaker you have.....hot wires can cause fires.....

Also....a quick acting breaker will have to be rated higher then a time delay breaker...you know fast blow versus slow blow.