Tig welding alu

[Dave Llew]

Hello to all,
I'm new on here and look forward to any/all advice I may receive from the masters on here, Thanks in advance.
I'm looking to get an AC/DC Tig, I've read multiple threads on which to buy in my range, I thought I'd made a decision, but came across the R-tech 210, which has the 4 wave forms, whereas the other options are all square wave variable frequency and pulsed, I am wondering whether I will have enough control over the heat with just the frequency and pulse, or if the wave forms makes a bigger difference in heat control than the pulse and frequency are capable?
Thanks
Dave

 

[Richard.]

My machine has 3 wave patterns but they can be adjusted on the half wave so I can have sin on the pos and square on the neg etc.
I never bother with anything other than square wave. It would never be a deal clincher for me if a machine had the option to change it. The only instance I see it been an advantage is from a link I've heard between harsh square wave and grainy appearance in silicon based fillers ie 4043/4047.
More often than not a tweak with settings and technique sorts it but I have heard a softer sin type wave helps reduce further. Don't select a machine based on this function. Square wave is IMO all you'll need.

 

[Richard.]

There are literiture selling points made by manufacturers to make you believe you need the selection of wave forms but I don't see the need for any thing other than square wave.
The softer sinius wave gives a softer arc and more fluent puddle. The tri wave is supposed to offer lower heat input due to the peaks in the wave but I prefer the focus of the arc which is best shown in square wave.

 

[Leetig]

Hi dave I own a 210 digital and have to say a great machine given the price. I also just leave it in square wave cos tbh I really couldn't tell much difference. The important ones are balance and freq which it has. If you do decide to buy the rtech I advise you get a different torch in the deal! Other than that I've no prob with it

 

[Appyasme]

Do i sense a Kemppi AC/DC 2300 coming on???

 

[Dave Llew]

There are literiture selling points made by manufacturers to make you believe you need the selection of wave forms but I don't see the need for any thing other than square wave.
The softer sinius wave gives a softer arc and more fluent puddle. The tri wave is supposed to offer lower heat input due to the peaks in the wave but I prefer the focus of the arc which is best shown in square wave.

Hi Richard, Thanks for that, it sheds a clearer light on my choices, I will no longer be governed by the wave forms, square it is . I was thinking the balance and frequency would do enough, but wasnt sure if the wave form affected in other ways, as you pointed out above with the silicon based fillers. Gonna have to look at the kempi mentioned by Appyasme now, didn't think they'd be in my price range

 

[Dave Llew]

Hi dave I own a 210 digital and have to say a great machine given the price. I also just leave it in square wave cos tbh I really couldn't tell much difference. The important ones are balance and freq which it has. If you do decide to buy the rtech I advise you get a different torch in the deal! Other than that I've no prob with it

Hi Leetig, thanks mate, its nice to get an opinion off someone who has the machine in question, I'll keep it in mind if I go rtech

 

[Dave Llew]

Do i sense a Kemppi AC/DC 2300 coming on???

Hi Appyasme, not sure, hadn't looked at them as I didn't think they were in my price range. Are they a good machine then, I haven't come across that option in my forum reads? must look now, it could change everything.
I just had a look, I see why it didn't come into my search results, its twice if not 3 times the price, unfortunately I cant justify that for my infrequent use, thanks anyway

 

[Appyasme]

Dave,are you looking at the new Kemppi AC/DC 2300 or the one i posted in "used equipment"

 

[Richard.]

^^^^
This guy is selling a very clean one at a simlar price to the new RTech . I know where my investment would be placed.

 

[Richard.]

Hi Richard, Thanks for that, it sheds a clearer light on my choices, I will no longer be governed by the wave forms, square it is . I was thinking the balance and frequency would do enough, but wasnt sure if the wave form affected in other ways, as you pointed out above with the silicon based fillers. Gonna have to look at the kempi mentioned by Appyasme now, didn't think they'd be in my price range

Balance, frequency and wave form shape are not really linked in regards they have different jobs to do. Balance is the % you set the polarity because AC fluctuates between DC+ and DC- so you set the % you want on DC+ or neg depending on the machine and the remaining is on the other side. More - is pen more + is cleaning.
(70% neg is norm)
Frequency is HZ. The number of times it fluctuates between the two polarities in a second. More Hz = tighter focus on the arc.
Wave pattern is as I discribed above and IMO is not an important thing to change as square wave appears to cover my Alu tig scope. Square wave is usually an inverter based type and transformers are quite ofter sinuous wave based.

 

[Leetig]

Hi Leetig, thanks mate, its nice to get an opinion off someone who has the machine in question, I'll keep it in mind if I go rtech

Yea it is a great machine. It's the same as the everlast powertig. Few vids on youtube on em with great reviews. I use a kempi at work but only on steel and can't tell much difference tbh. However ac welding could be another story!

 

[Dave Llew]

Dave,are you looking at the new Kemppi AC/DC 2300 or the one i posted in "used equipment"

I was looking at new, I'll have a look now

 

[Tinbasherdan]

That kemppi is well worth a look, they are gorgeous machines to use and I'll be honest if it won't do the job, then neither will you!

 

[Dave Llew]

Balance, frequency and wave form shape are not really linked in regards they have different jobs to do. Balance is the % you set the polarity because AC fluctuates between DC+ and DC- so you set the % you want on DC+ or neg depending on the machine and the remaining is on the other side. More - is pen more + is cleaning.
(70% neg is norm)
Frequency is HZ. The number of times it fluctuates between the two polarities in a second. More Hz = tighter focus on the arc.
Wave pattern is as I described above and IMO is not an important thing to change as square wave appears to cover my Alu tig scope. Square wave is usually an inverter based type and transformers are quite ofter sinuous wave based.

Hi Richard, most helpful, I'm going to look at that kempi appyasme posted now, if its not gone.
I understand a lot of the electrical side as I'm qualified in electrical/electronic engineerings, but just havent had the experience or training on a tig, at least not for 20 odd years. So, if the kempi is gone, would 0.5-150Hz or 50-250Hz be a more useful range, I'm deducing both would have their advantages, but 0.5-150 would possibly give me more heat control and time to be steadier( as im a novice), but 50-250 would give me more focus? As I understand it, the more expensive machines have a much higher top frequency(around 2000Hz?) and start at 0.5hz or so? so maybe 0.5- 150 a better option?

 

[Dave Llew]

That kemppi is well worth a look, they are gorgeous machines to use and I'll be honest if it won't do the job, then neither will you!

Like it I know its an art to learn, but one will endevour

 

[Tinbasherdan]

General rule of thumb, the higher the frequency the tighter the arc, but to be completely fair ive welded miles of ally vent and don't think I've ever gone over 150hz

 

[Dave Llew]

General rule of thumb, the higher the frequency the tighter the arc, but to be completely fair ive welded miles of ally vent and don't think I've ever gone over 150hz

Brilliant, That's what I was hoping. What sort of thicknesses are you welding?

 

[Dave Llew]

Where do I find the used machines?

 

[Richard.]

2000hz is unheard of as far as ac freq is concerned. You'll not need any more than 120-150 max. Arc stability is by far more important.
Fwiw my fronius goes up to 100hz it's an old machine but I never feel restricted by it as the arc is so sharp and stable.
Don't worry your self about the scope on the bells and whistles. Look for arc stability, HF accuracy and the accuracy of the digital readout ie if you set 100amps you should get 100amps. The rest of it will be fine.