Welding Tips and Tricks

Hey,

Hang in there mate. Someone will have something for you. I have about zero experience on Al so i shouldn't give any advice, but because its the festive season, other regular contributers may be off line. keep checking in and someone will help out.
Mick

Hi, xivlia,

If the machine meets it's claims, It'll be more than adequate for your plans.

I can't speak for this particular brand, but I can make two general observations:

While many Chinese-made welders are not ready to compete with their established counterparts, they have been steadily improving.

The price for the fuctions offered seems a little low to me. In your place, I'd try to locate a few folk who already own it, preferably experienced weldors, and ask for their reviews.

Steve S

hmm i understand, i will try and see if anyone has got one of these. i have one more question.

those chinese welders are DCEP, it shows the torch as + and workplace as - on the machine, will it be possible to reverse the polarity? will it damage the machine? or does it not matter

It must be possible to reverse the polarity, as DC TIG is always DCEN. It might be automatic with the machine settings.

Polarity is a non-issue for Aluminum, as it's AC.

It might just be the way they've chosen to mark ground (workpiece) vs. electrode.

Steve S

ah okay, i was just wondering and i didnt know if TIG machines are made to be specifically one way ie, DCEN or DCEP. i didnt know you can alternate between them even though it has + and - marks on the machine.

Well reading this really hasn't improved my mood...
The first half of day two was spent at college trying to learn how to weld aluminium on DC by mistake. I was using 100% argon and i was convinced i'd got horrendous contamination judging by the black crust on the weld. Which is why i bought a stainless wire brush and acetone for the following night.
Of course, the following night i discovered that you weld stainless on DC and not AC. All became clear then as i realised i'd been welding on DC all night as my stainless welds looked great
So as it stands now, i now know i can't weld on either polarity
Can't wait to try it the 'pause-lift-dab-down-forward-pause etc' Jamie method though

Dear Friends , I would like to make a little note here , I had a 160 Ampere DC only machine and I had to stick with it for many years before I buy an AC /DC machine .
Any way I had to weld some aluminum jobs and I tried this , I took stick aluminum electrodes Si 12 the 4043 it has 5 %Si and I weld with DC and argon
At normal flow or a bit less . The heat of torch melts ( 2 % thoriated RED 2.4mm ) the aluminum base metal the paste also melts and cleans the surface of aluminum oxide then melts the stick electrode core which is aluminum eventually it mixes with the base metal puddle . The quality of the weld is poor and you also have to remove the paste that solidifies as you do with stick welding with a chisel .
I also know that OTC a Japanese welding machine combines AC with DC so at
Tig process AC cleans for few secs then DC takes its place at this point you add the filler metal . It claims that melts a lot better and nicer than the traditional AC only machine.. So I think that Helium can work and it a very good idea that i think it is interesting well done ...
ESENTI

I'll have to explore that OTC machine you mentioned.

It makes a lot of sense, if set up like pulse. Say, a second of balanced AC for the cleaning, with a burst of DC for penetration? Or even a thumb-switch... AC until you're ready, press the button and feed the rod under DC?

Interesting concept.

Steve S

This is the short description for the OTC manual as you might like to see Dear Steeve the machine is OTC ... DA-300P this is from the manual ...

ESENTI ...

Thanks, ESENTI,

That's what I was thinking you meant. What you just shared suggested it for an automatic (semi-robotic) process, but I can see manual uses for it, either by learning to work with the preset rhythm, or with a manual switch to activate the DC mode briefly for filler-feed.

I don't get enough aluminum work to justify a purchase, but, we're expecting a Miller SW250 back that the repair cost was too high for (we bought a new one instead), and I'll be able to experiment with it at will.

Steve S

Steve , It says mostly , it can bu used in either way by a welder manualy or automation , and the machine does it itself I canot see how you can do it in a machine that has not been desined for this .Switching ac to dc is imposible while you work on an aluminum it remains only theoritcal aproach at the moment ...
I dont know this model and in my area is very rare to see MIller Machines,(Europe ) even that i know that it is represented it in Italy ..
but i know that are very good machines ...I have Fronius magic wave 220 ...Which is i think even better ...

Esenti

I'm jumping in a little late on this discussion ... but wanted to share a pic of some DCEN w/ helium on aluminum. Originally, TIG was trade-named HELIARC because the process used DCEN w/ 100% helium. But, today AC is the most common and preferred method for most applications ... it produces good results and argon is cheaper than helium. But, the application in this photo would not allow for any surface "etching" caused by an AC arc ... so it was welded with a Miller Aerowave in DCEN. The edges of the weld look a little smokey - but otherwise they turned out pretty sweet.

That's slick, Brent!

I have access to all the (high-purity) helium I can use, and have yet to have an excuse to try this. It's coming...

I have used He/Ar, at aprox. 50/50 on HFAC aluminum for thick sections, and the difference is impressive!

Steve S

Telling yeah it works great if the settings and the hands are there. Plus, it's nice and quiet, ha ha! Thanks for sharing Brent.

Any doubts about the quality of aluminum welds done with DC and helium should be forgotten. Short runs, peen and allow to cool, repeat.

All Rodeck top fuel dragster blocks and heads are repaired with DC. Also many historic auto race engine blocks, e.g., DFV Cosworths

Pioneered, or perfected, I believe by ; http://en.wikipedia.org/wiki/Epperly

New poster here. Thought I would start somewhere. I recall many years ago when I was working as a rocket engine mechanic and assembler at Rocketdyne in Los Angeles California, I marveled at the lovely welds done on the alumnum liquid oxygen ductings and also on the stainless steel ductings used for the engine fuel.

In time, I got to know most of the weldors in the plant and I was often permttted to observe the welding being done. As I recall, all of the welding on both aluminum and stainless steel parts was done with DC and helium. Additionally, all of the machines being used were straight transformer units and were quite large and powerful. This was when the process was called Heliarc. This was also long before the common use of digital equipment capable of producing square waves superimposed on AC power. It spoke highly of the skill of the weldors using what equipment was available at that time (late 1950's) All of the welds were X-rayed and stamped by an inspector as well.

It helped of course, that the company had sources for their high pressure cylinder gases, in particular helium. At that time, cost wasn't that much of an issue, I guess. While it's perfectly clear that excellent welds can be done providing stacks of dimes, nickels, and quarters, LOL, the cost of helium and the fact that a larger machine is needed would make DC with helium prohibitive for a hobby weldor such as myself. I have a Miller Syncrowave 200 that serves my needs very well with Argon gas. With Argon currently costing me something like $70 for a 160 c.f. customer-owned cylinder exchange, I can't even imagine what helium might cost. I really don't know because I have never tried DC with helium. Nonetheless, it's certainly possible on aluminum.

Hey
Welcome to the forum. I liked your little slice of history. Keep it coming.

Mick

I thought I would contribute to this thread's longevity by adding a penny to it. DCEN for welding aluminum? Why not? If the surface is prepped sufficiently and a greater amount of oxidation is removed, then there is no need for cathotic etching. Deep penetration and a clean bead all at the same time. BTW, in the picture above, provided by bdoublew, the torch angle looks a little bit much. What do you think? Long live the thread!

weldin mike 27 wrote:Hey
Welcome to the forum. I liked your little slice of history. Keep it coming.

Mick

Thanks Mate! I'm always pleased to hear from folks in Australia. I have many Internet friends and associates in the motorcycling and machining world from OZ.

Regards, from Sunny California.

Pleasure mate, One of my dreams in life isnto get over to Southern California to check out Tehachapi and Cajon passes. (rail fan post hijack)

Nils wrote:BTW, in the picture above, provided by bdoublew, the torch angle looks a little bit much. What do you think? Long live the thread!

Yes, I think the pic was taken during post flow ...

DC root pass on .750 to .750 beveled butt weld on good old 6061 Aluminum. After wire brushed and acetone wipe for cover passFull length root pass.

Hi all: I am new here, and very interested in purchasing a TIG welder for home/projects/etc. There are not a lot of
options at the low end, which are decent quality (I am trying to avoid cheap Chinese machines), so I was considering
a DC TIG/Plasma combo. Then I found this thread; very interesting as perhaps I can get away with a lower priced
DC only TIG welder. The tips sound interesting as an option for someone who will not weld aluminium very often. Any
further feedback is welcome. Cheers.

Jose aka Desert Warrior

Good to see this DC aluminum talk. I only now have a Everlast PA 160STH and I was told that I could not weld aluminum. Well that is a bad thing since one of my projects was going to be a flat boat. Let me ask, if you have a AC stick can you weld aluminum with those after market TIG rigs?

Hey,

I wondered that myself, but I have come to the conclusion that AC without high freq stabilisation will not work. Hence Jody's video with the AC buzz box hooked up to a rectifier to convert it back to DC. This may be crap, somebody out there will correct me if im wrong.

Mick