i am welding a very complex part at work and need some advice.its 6061 and im welding 3/16 plate to 1 1/4 billet on an inside corner.the billet is about 1 1/2 foot long.i did a few test pieces with a small chunk of 1 1/4 on 3/16 plate and i got it to work but then when i go to the part the large size is where im running into problems.i had to rent a miller 350dx.its a pretty new machine with pulse and all the bells and whistles.so where i left off i was running at 320 amps with ac and pulse on with green 1/8 pure tungston with gas lense 100%argon.the tungston was starting to really go away.i have a bottle of 75-25 helium mix there i can use.as well as a torch i can pre heat the hell out of it.we also have an oven that i could throw it in and pre heat it in that too.any help here would be great.i have been welding for many years and i dont really weld this thick stuff to often and of course this guy im working for wants it done yesterday and does not understand what it takes to get set up to do it right.

 

Your not supposed to run greens with the dynasty 350s. Get some lanthanated 2% (blue) or ceriated 2% (orange) and that will hold up a hell of a lot better. Set the machine for advanced square wave (use the manual it's a hidden menu) and turn your frequency up to 400hz.

 

its wired in at 230 volts.i thought this shop had a 460 outlet but its only got a 230.so will i be able to adjust the frequency to 400hz?thanks for the info on the tungsten.i thought you had to use pure when welding with alot of amps like well over 200.is the advanced square wave function a preset?i mean is that it with no other tuning involved.just put it in the mode and go?thanks for the input

 

why not use 1% Zirconiated Brown tungsten

 

i just looked up the manual for this machine and its a 350 lx.i couldnt remember what it was.so from the advice that crmb had said about adjusting the frequency to 400 hz i guess thats not possible on this machine.being its not an iverter.as for tungsten the miller manual says to use orange for above 220 amps on ac.i dont know alot about these other tungstens.i have only really used red and green.thats all that i have needed being that my home machine is only a 180 amp.

 

350lx? is it a dynasty or a synchrowave?

if it is a dynasty it is still an inverter, you just don't have ac frequency adjustment.


Don't bother with ceriated on something that big, up to 200 amps it lives ok but it will tend to split on a job like this in my experience. I like zirconiated but lanth is good too.

I would clean it all well, set the machine to 80% dcen and crank it right up, and preheat the thick piece to 300 degrees or so. easy.

If it's a synchrowave do the same thing but set cleaning to 70%. You'd better have a watercooled torch and a 1/8" tungsten.

 

You got all the right ideas.

Preheat is a must.

CRMB is correct on the Tungston to use.

We have a 350 here should handle it with no problem.

 

for something that thick, preheat is a must. use the oven/furnace if you can fit it in there. i have a hot plate that i use occassionally, but i wouldn't attempt something that thick in aluminum with my welder.

 

yea its a syncrowave machine.pretty new too.its big like 4 1/2 foot tall.there is a nice size oven there that this part will fit into.so pre heat to 350?yea this machine is water cooled.built right in.i was using 1/8 pure and now i find out that its not right for this high of amps.

 

Can't tell from the description - but if it's structural, you may not be able to pre-heat very much of it. You don't want to anneal the whole thing.

 

yea thats kinda what i was thinking too.there is a nice torch set up there .im thinking about just heating the billet and seeing how that works first.

 

Preheat the thick part some turn off the pulser (you loose allot of capacity or heat input depending on your settings and you don't need it for this) set the balance for less cleaning helium is also a help 20cuft flow 2%thor or pure will work 7 or 8 cup will also work

 

I think you'd be suprised at how much just a 300 degree preheat would help actually.
Keeping preheat under 400 will not affect the temper and still make it a LOT easier to weld.

The welded area is always going to end up annealed, so if it's structural hopefully that fact has been engineered into the part.

 

yea its a structural piece.its the center spine of a motorcycle.its over engineered to so it should be fine.i will ask the engineers what they think as far as heating the whole thing or just the thick billet part.im getting some orange 1/8 tungsten too.so im hoping that i can show up and get this done in a reasonable amount of time.keep my fingers crossed.

 

I find zirconiated is hands down the most stable on AC current, but we only use inverter machines, not sure how much of a difference it makes.

 

i guess it does make a difference.miller says to use orange ceriated to hold up to this kinda amps on a syc 350.the green just goes away very fast and im using 1/8.im not sure about the brown and holding up to 340 amps?im stopping on my way into the shop and getting some orange.i will ask them too if there is a better one to use on this machine.thank you all for the advice on this.

 

I agree on the zirconiated. Works the best for me on both inverter and transformer machines.

I find ceriated gets weird and tries to split running high amps on AC.

 

Get some helium. Run it on DC and it will work a lot better. but you should do some test pieces to get the feel for welding with DC and helium. Gotta move a lot faster.

 

alright well i will try the zerc.i have some 75-25 helium mix there that i will try too.i dont have any setup time left.this guy is kind of a jerk and i need to just start welding on it.i would really like to spend one more hour setting up to do this right but this guy is really pissing me off.so the fact of the matter is if your going to rush me through something like this you will get what you get.

 

well the job from hell is done.it took all day to weld this thing.the damn breaker kept popping so i only could weld with 200 amps.i stopped to get some other tungsten and all they had was gold.it worked better then the green.it turned out looking pretty good.i had a little trouble with some of the welds cracking on me from all the stress on this thing.i was able to go back and re weld the cracked areas and its ready to send out for stress relief at the heat treater.

 

Ding ding ding we have a winner. Run your gas flow a lot higher too. Good times. You get a lot more penetration with DC as well.

 

yea i didnt try the helium.got it done with ac and 100% argon.i heard that it was messy with dc.is this true?i have used 75-25 helium and it worked ok.the 25% helium gave a bit better penetration.