tri mix

By welder5354 (**)

Date 09-05-2010 02:47

why trimix.
100% Argon is ok. And it will give you excellent reults.

By yorkiepap (***)

Date 09-05-2010 13:10

Hey weaver,
I've never used a tri-mix for aluminum. There may be instances that it would be necessary, although the parameters would have to dictate if so. Here's a site that will inform & educate you regarding gasses & their applications that work best. This gentleman did all the homework..... use it.

Denny

http://www.weldreality.com/MIG_welding_gases.htm

By Milton Gravitt (***)

Date 09-06-2010 17:28

I've have never heard of a trimix on aluminum but it could be,but I've used a mixture of argon and helium.
M.G.

By js55

Date 09-08-2010 13:32

I would not recommend using anything but inerts with Aluminum.

By 803056

Date 09-08-2010 19:34

What's sa matter? You think maybe a touch of Oxygen might cause a bit of a problem?

I assume you are using GMAW- spray mode transfer, if so, Argon should be fine until you exceed 3/4 to 1 inch material with CJP grooved joints. The extra heat bought to the party with some Helium additions should help the issue of producing sufficient heat input to ensure good fusion.

Go with the largest filler metal the highest amperages the welding equipment and the welder can handle. Use heavy gloves with aluminum reflective pads.

Best regards - Al

By weaver

Date 09-08-2010 19:49

I am not trying to be funny, but i have never had a problem with tig on alunimum. i don't know if i recieved bad filler or what. I tig alot and cannot get the finished bead to be shiny, no matter the ac balance. this job has fought us the entire way. I am running a miller syncrowave 250, using 5356 rod 1/8'' , 1/4'' material. and about 20psi on the reg. oh and around 230amps sometimes around 214amps. everyone is differnt.

By Lawrence (*****)

Date 09-08-2010 21:34

A chrome-shiney appearence on an aluminum bead crown is not a quality requirement in any code I'm aware of. Especially at 200 amps..

Often a shiny crown is cause to question sufficient heat input in fillet welds.

One technique that might help would be use the largest filler wire available for your GTAW and add it quickly to keep the puddle cool..

Slow travel speeds can cause overheat conditions that will eventually entrap hydrogen and the grainy appearence on the crown (tiny hydrogen bubbles unable to escape) can cause RT problems.

So hot and fast with a large filler rod is the best thing I know if you are looking for a shiny weld crown...

By 522029

Date 09-09-2010 00:24

I hope you mean "20 cfh" ???

Griff

By weaver

Date 09-09-2010 02:53

yes

By welder5354 (**)

Date 09-13-2010 02:49

I would also recommend a little pre-cleaning which i do all the time.
Get some acetone and put it in a spray bottle.
Spray the acetone around the joint to be welded and then clean with stainless steel brush.