Page 1 of 1

how to start

Posted: Sat Aug 15, 2020 1:51 pm
by croshaul
I've been playing with a piece of 5" x .060 aluminum pipe. I've been cutting it into small segments and cutting them open to make a butt weld seam back to pipe. I clamp them to give me a good fit and tack but I can't get started on the edge without blowing it out. I have my machine set at 50 amps, frequency at 100 and balance 70. I can run a good bead once I get into some meat. I thought about putting some backing but it feels like a cop out.Seems I should be able to get started.

Re: how to start

Posted: Sat Aug 15, 2020 2:12 pm
by Oscar
Simple. Take off your skirt and put on your big boy pants. ;) Set the machine to 80A. Zero-gap. Hammer it and get ready to feed it rod almost instantly. That's how I do it. Not easy, but it is my preferred method. Then learn how to feather out the arc as the part heats up.

Re: how to start

Posted: Sat Aug 15, 2020 3:13 pm
by LtBadd
Don't know what machine you have but 70% EN is too much if that is what your machine is set at.

Using backing is not a cop out, it's a tool to complete a job successfully.

Maybe easier to practice on .060" flat stock butted together?

Re: how to start

Posted: Sat Aug 15, 2020 4:35 pm
by Spartan
What they said.

Also, unless you're welding to a specific code, which it sounds like you are not, you can start just off the edge (maybe 1/4" or less in any direction that works best), and then quickly get over to the edge to begin the bead. Can really help control blow out on arc start on thin material edges sometimes.

Also, if you're new to TIG (don't know if you are or not), it can be helpful to practice all of the tips above on steel before you start applying them to AL. Steel is much more forgiving in these regards, and it will help you to master it there, before taking those same skills to AL which is a bit more challenging, IMO.

Re: how to start

Posted: Sat Aug 15, 2020 6:35 pm
by croshaul
Thanks, Are shorts OK Oscar?

I'm on an HTP 221. I'm expanding my horizon :D

I've been welding for years mostly stick construction work,I did some tig welding at work on stainless and scratch start was all we had. I did pass a test for boiler tube welding, we had to weld a schedule 240 6" coupon with a tig root, stick cover and back to tig to finish we were using inconel for the final passes. I did a little bit of aluminum with a hi freq box, nothing like this machine I have now though.

I'm just playing around trying to learn how frequency and balance come into play. I'm still trying to figure how to set things up with the aluminum. Read the HTP manual, go to the forums and watch some you tube videos to get some ideas.

Re: how to start

Posted: Sat Aug 15, 2020 7:14 pm
by Oscar
I suppose, but I hope you get my drift, lol. The vast majority of beginners trying to TIG aluminum, for some reason unbeknownst to me, simply set the machine way way way too low. I still can't figure it out why, :lol: Can't tell you how many times I've read about someone trying to weld 1/8" thick aluminum with 75A (just as an example). And even then, I'd be willing to bet they were just baby'ing the pedal and expecting a supernova-like powerful arc, with probably like 20A out of those 75A. The fact is you need a good amount of amperage to get aluminum going quickly. Is it possible by using 1amp-per-1thousandth guideline? Yes, but it will heat soak the part quickly due to aluminum's excellent thermal conductivity. Then at the end of the bead, you can watch it widen out about 3x the size and then drop right out and leave a big hole in the part. I say, weld it hot 'n fast at the beginning, feed it rod, and learn to ease up on the amps towards the end. Oh and it also helps if you add in a big "blob" tack at the end if it is permissible on the part. It will help not destroying the edge/corner/end of the weld with a blow-out.

Re: how to start

Posted: Sat Aug 15, 2020 7:15 pm
by Oscar
LtBadd wrote:Don't know what machine you have but 70% EN is too much if that is what your machine is set at.

Using backing is not a cop out, it's a tool to complete a job successfully.

Maybe easier to practice on .060" flat stock butted together?
Why would 70% EN be too much balance? Not sure I'm following you as to why.

Re: how to start

Posted: Sat Aug 15, 2020 8:24 pm
by LtBadd
Oscar wrote:
LtBadd wrote:Don't know what machine you have but 70% EN is too much if that is what your machine is set at.

Using backing is not a cop out, it's a tool to complete a job successfully.

Maybe easier to practice on .060" flat stock butted together?
Why would 70% EN be too much balance? Not sure I'm following you as to why.
because he's welding thin (.060") aluminum

Re: how to start

Posted: Sat Aug 15, 2020 8:52 pm
by Oscar
I see. I can't say that I follow that methodology in order to control the heat. To me, that is what the main welding amperage is for, with the balance playing a minor secondary role. But like I said, that's just how I see it.

Re: how to start

Posted: Sat Aug 15, 2020 8:56 pm
by Oscar
croshaul,

Here is some experimenting I did with 16 gauge (0.062") aluminum angle. I was teaching myself how to tack the up. Many many moons ago, but I still refer to it because I think it's good info. These were blast tacks, with the pedal, letting up pretty much as fast as I could once the arc hit the joint.

Image

Re: how to start

Posted: Sat Aug 15, 2020 9:06 pm
by BugHunter
Some manufacturers refer to balance as percent en and other ones percent EP. 1 calls it 70 the other calls it 30, and they really are the same thing.

I like using a longer finer point in order to really control where the art goes. If you have a setting for higher frequency, use that. 200 Hertz will focus your power more then 100 Hertz. It becomes a little more forgiving on the thin material that way. At least I find it to be so.

If you want to light up on an edge of a butt joint, on aluminum, you really have to have it super clean and with really nice smooth edges so the part will accept Heat very evenly.

A trick I often use is to lay the filler rod on top of the joint and use it to sort of protect the part, almost like you're trying to get it to absorb excess heat so you don't blow through the edge. If you light off on the filler rod and then pull it out of the way and then wet your puddle, I sometimes find that easier to hold a tight Arc and really concentrate the heat only where I want it.

I find it especially helpful when I don't want to turn off the hot start option (lazy), so I make the filler Rod absorb the hot start and then move to the park once my pedal control has become completely linear.

Re: how to start

Posted: Sat Aug 15, 2020 10:21 pm
by LtBadd
Oscar wrote:I see. I can't say that I follow that methodology in order to control the heat. To me, that is what the main welding amperage is for, with the balance playing a minor secondary role. But like I said, that's just how I see it.
With AC, weld EN amps is the main factor that inputs heat into the weld, reducing that input is a major player. I can turn the main amps up and have reduced pedal control or turn it down and allow more use of the pedal. Sure I can weld at 70% EN on .060" material, and an experienced TIG could probably deal with that but it's a less then ideal situation.

Let's take this to the extreme, a setting of 90% EN and thin material, or a setting of 60% and thin material, which would be easier to do?

Re: how to start

Posted: Sat Aug 15, 2020 10:28 pm
by Oscar
LtBadd wrote:
Oscar wrote:I see. I can't say that I follow that methodology in order to control the heat. To me, that is what the main welding amperage is for, with the balance playing a minor secondary role. But like I said, that's just how I see it.
With AC, weld EN amps is the main factor that inputs heat into the weld, reducing that input is a major player. I can turn the main amps up and have reduced pedal control or turn it down and allow more use of the pedal. Sure I can weld at 70% EN on .060" material, and an experienced TIG could probably deal with that but it's a less then ideal situation.

Let's take this to the extreme, a setting of 90% EN and thin material, or a setting of 60% and thin material, which would be easier to do?
I totally see what you mean, how it can limit heat input because EN is reduced, but IMO it's not a major player, at least I choose to not use it as such. I also disagree with "reduced pedal control", for that is also in the 'foot of the beholder' as to how well or not they can control the pedal, even though numerically yes I do know the resolution does change with a different max main amps set at the machine.

Re: how to start

Posted: Sun Aug 16, 2020 11:53 am
by croshaul
I'm not good enough to play the peddle like that so high amps in this situation doesn't work for me. Playing with the frequency and high EN numbers has given me better results. I still haven't hit it yet but seeing Oscars pics I'm going to crank my frequency up. I've only gone to 120 so I've got some room to move. :D

Re: how to start

Posted: Sun Aug 16, 2020 12:54 pm
by Oscar
croshaul wrote:I'm not good enough to play the peddle like that so high amps in this situation doesn't work for me. Playing with the frequency and high EN numbers has given me better results. I still haven't hit it yet but seeing Oscars pics I'm going to crank my frequency up. I've only gone to 120 so I've got some room to move. :D
There's definitely a few ways to skin the cat. Then there is also Independent amplitude control which has it's own set of benefits that you could exploit on your Invertig 221. Hit us up in the HTP WhatsApp Group chat!

Re: how to start

Posted: Sun Aug 16, 2020 1:49 pm
by croshaul
How do I get to the group?

Re: how to start

Posted: Sun Aug 16, 2020 2:15 pm
by Oscar
PM sent. :)

Re: how to start

Posted: Sun Aug 16, 2020 4:52 pm
by croshaul
Done, another new adventure :)

Re: how to start

Posted: Sun Aug 16, 2020 4:58 pm
by Oscar
croshaul wrote:Done, another new adventure :)
You sure? I didn't see the notice on the group chat saying that you had joined. It's ok if you don't want to. :lol: