But there is more than one way to skin a cat when tig welding aluminum and if you find your 200 amp tig inverter bonking a little bit when you light up on thick aluminum...If you have to wait more than 3 seconds to get a puddle...If the sound of the arc force makes you hunt some ear plugs, then this tip is for you.
Tig Welding aluminum 1/8" thick and above goes a lot better with helium added to the mix.
In fact, I like to use a helium argon mix on pretty much any aluminum I tig weld....To me, even aluminum as thin as 16 ga welds better and faster with a little helium added.
I know a lot of you dont want to spend extra money on an extra tank of gas and the extra fittings, regulator, and flow meter it takes to make it happen but if it means having enough heat to get you over the hump on those infrequent thick tig welding aluminum jobs, its something to think about.
Its a funny thing. A lot of effort has gone into developing and marketing tig inverters. Some of the benefits and features are:
a more focussed arc,
being able to use a smaller electrode,
better bead profile, etc.
But what is not talked about very often is adding helium to the argon to achieve all those things.
If you already have a tig welding machine and are looking to upgrade to an inverter. Most of the benefits can be had just by getting a tank of helium, another regulator/flowmeter and mixing it with a Y fitting along with 2 check valves.
I think its the biggest single improvement you can make for tig welding aluminum. Definitely the most bang for the buck.
So The tig welding project here is an aluminum diamond plate tank that will be used later for a new design tig water cooler.
Its 11 ga which is 1/8" or .125" thick. No I did not need to use a helium argon mix to weld it. I just did it to show the difference in the amperage it takes to weld aluminum with pure argon versus adding helium.
For this little welding project, I used a 80/20 helium argon mix...thats 80% helium. I have found thats is about the maximum helium you want before you start to lose arc starting and arc stability while still getting the most heat for the amperage run.
I could have easily tig welded this project with pure argon and have done jobs like this many times that way.
By tig welding aluminum with both argon and with 80/20 he/ar in the same video, we can learn something. Thats what we are here for. right??
For tack welding aluminum diamond plate, I set the amperage to about 165 and use the trick I wrote about on another video page about an Aluminum Tig Welding Project tack welding tip where I hammered the amperage really quickly to tack weld the outside corner joints. I used the 80/20 mix for the tack welds.
For the first welds, using the 80/20 helium/argon I found that about 90 amps was about as much amperage as I needed to travel pretty quickly so I set the machine to exactly 90 amps and welded full pedal.
Then I switched gears and changed over to pure argon.
The same 90 amps at full pedal was barely enough to get a bead going.
I had to wait a few seconds to even get a puddle going and it was a slow go after that....I had to increase the amperage to 125 to get the same heat and travel speed I got with 90 amps using the mix...and not only that, but it welded much cleaner and better using the mix.
Now, let me be clear. Helium is more expensive than argon. You dont want to use it for every job that comes along.
But here is the thing. If you get a tank and the fittings to Y it in to your system ...and only use it when you need it...one tank of helium will last a long time...like maybe a year or more if you only use it infrequently.
I have a couple tig inverter machines and one is a Miller Dynasty 200dx. Its a great little tig inverter. But it only has 200 amps and that is not always enough.
when my machinist buddy brings me a 1 inch thick piece of aluminum that he misdrilled, I need all the help I can get to get a good weld with a 200 amp tig inverter.
so here is what I do... I heat it up on the grill or stove while I have a beer.
I turn on the valve on my Y valve so that I get about a 50/50 mix or more of helium. It takes a little more flow than pure argon so I usually set the helium to about 12-15 cfh and the argon to about 12-15cfh.
When the part is good and warm like around 200 degrees f, I grab it with a heavy glove and weld it with the amperage set to 200.
That usually does the trick and its a lot better that buying a bigger machine.
If you dont do thick aluminum, just log this tip away for later.
But trust me on this one.
Just giving a good tip for tig welding aluminum.