I purchased a syncrowave 200 runner and attemped some aluminum welds and had a little trouble getting a pool started. In A/C i used a 3/32 pure tungsten with 3/32 4043 aluminum rods with a about 90 amps on a junk valve cover. Im new to this so any advice is appreciated.

 

Learning on a valve cover (especially Honda ones) are not easy at all. The Honda casting sucks and tends to pop and get contaminated quickly. I'd learn on some clean material first.

 

try welding on a smaller piece to start out. Being that you're starting out on 90 amps its going to take a lot of time for that entire piece to heat up. Also make sure you're on high frequency contin.

 

Hey there,

I'm about a week into using my 200DX and I love it...
I would recommend starting out with some clean scrap aluminum of various thicknesses to gauge the amount of amperage you need, as well as changing the DCEN/DCEP ratio's for how clean the metal is.

I have personally found that in my manual it states 120-160 amps for 8th inch thick aluminum, and i was always melting though, I turned the dial down to 60-80 amps slowly ease into the pedal and you will see how much of a puddle you get small vs large vs "I have a hole"

I have noticed that the window for puddle vs deform part is a very very small window.

Keep at it!

--Aaron

 

60-80 amps is way too low for 1/8" aluminum. thats what you should be running it at for 1/16" aluminum. if you are opening up a hole, you are going way too slow. Since you said you have had your machine for a week, I would bet you are indeed going to slow as that is commin for most new TIG welders to do. also, slowly easing onto the petal is pointless on aluminum, you are better off pegging it right off the bat (assuming you have it at a proper amperage setting), so you quickly get the metal fluid enough to add filler, and then of course add or subtract amperage as you go as needed.

60-80 amps on 1/8" is going to leave some cold welds or your work piece is going to be saturated with heat from having to go super slow to keep a good puddle going.

I agree with others on practicing on some scrap metal, not a valve cover.

 

E-Rok,

Thanks for the tips "don't want to take his thread away"

I should have worded the ease into the pedal bit differently, My goal was to slowly push the pedal down and watch what the aluminum does
get hot --> small melted spot -> larger melted spot -->I have a hole

Maybe I am moving to slow again I'm learning.

But this thread was to help someone else and not me

Thanks again,
--Aaron

 

well I think the info helps him too. theres a fine line with aluminum between too cold and the point where its too hot and it "flashes over".

 

Yeah I know! that's what I realized before..
I had a harbor freight tig for about a week and learned on that so I kinda have 2 weeks, but when I did the aluminum it was either too hot and melted though or not enough heat.

My advice is keep fiddling with it! but use clean metal so you know what works then you will realize when you have shitty metal what to expect.

--Aaron

 

i watched video's of guys weld aluminum on dc instead of ac...they say when you do it with dc you dont need to wait for heatup....its almost instant....they also said dont believe that you have to weld aluminum on ac

 

lol ok

 

i got a couple dvd's where the trainers do a pass on aluminum with dc and then a pass on ac and show you....it can be done and i couldn't see the difference between either pass

 

Yep it's done with dcep

http://weldingweb.com/archive/index.php/t-3609.html

 

im not saying it cant be done, but every video I have seen of it, it looks like ****.

ever balled a piece of tungsten on DC+? **** is like a huge flash of light, hard to see anything really.

 

It has been done. But oviously it's not the ideal method. I haven't tried it no need AC works fine for me

 

iv heard dc on aluminum is good for thick stuff, why? i dont know. but i dont think anyone on this site is gonna have to go down that road anyway for this type of fab work.

 

here is something i read about it

"I hate to differ with the post that stated that you cannot weld aluminum with DC tig. It is entirely possible to weld aluminum DC TIg. It take high current and produces x-ray quality welds but you have to know when to add filler metal. It doesn't get all shiny like AC High Frequency. It remains a lusterless aluminum finish under the arc. The trouble with welding Aluminum with DC is that the surface oxidants are not removed by the reverse polarity of the AC pulse. Only the straight polarity is used, hence DC. If you don't have the joint supported you can loose the whole thing in a melt down. The joint will just fall away. DC TIG is really useful in welding heavy aluminum weldments with a cross section of 1/2 inch or greater.

Actually, welding aluminum with DC straight polarity is preferred in applications where AC is a problem. You will have to scratch an arc, the spark won't jump the gap like in AC HF. I like welding with DC SP because it keeps the heat affect zone from spreading completely across the workpiece like AC HF does. It will get hot, make no mistake, but it will keep the heat in a more localized area until the wonderful heat dissipation quality of aluminum takes over. That's one of the reasons that aluminum is so difficult to weld. You have to get it so hot that the base metal melts before the surface oxidants do. It's the reverse polarity part of the arc that breaks through that oxidant and allows the base metal to melt. If you use reverse polarity to "ball" your tungsten, than you've seen this cleaning action first hand. But, since the tungsten will melt long before the base metal does, one can't weld with DCRP unless you use a very large diameter tungsten and then your welding machine would have to be capable of huge voltages and amperages to handle the currents, and that ain't practical."

after reading everyone saying you have to use ac for aluminum and then watching the trainers in the dvd's weld aluminum with DC i was like WTF?

 

Do you grind your tungsten and if so how sharp? Thanks for all the info guys

 

I grind it to a sharp point, even on AC for aluminum. it will form a ball on its own within a couple of seconds, and will usually hold that shape unless you are overheating it. for example, I like to use 1/8" pure tungsten for aluminum thats around 1/8" thick, opposed to 3/32" tungsten? why? because when I grind it to a point, the ball it makes is about the size of a 3/32" tungsten, but since its 1/8" tungsten, it will hold the shape much better, and I can weld for hours and it wont change shape or erode away at all.

some people like to use red (2% thoriated) for aluminum, but I find that it doesnt hold a ball for ****, and the arc sucks at that point. this is on transformer machines of course.

 

I was able to get some fairly decent welds but had a few issues

what is wrong when weld has black film?
what is wrong when aluminum sticks to electrode?
what is wrong when electrode gets short fast?
what is a good staring point for amps on 1/8 aluminum?
how do you clean electrode after contamination?
what is a good gas rate?
when you grind the electrode and point wears off do you regrind?
Is my miller syncrowave 250 a good welder for custom fabrication?
remember im a noob on tigging just looking for some experienced advice.

I was also able to weld valve cover but had to get real hot before adding filler rod

 

honestly starting with aluminum is a bad idea. I know your probably anxious to start making parts and getting some work done, but since the Al doesnt really change color as you weld it is significantly harder to work with if you dont know what your doing. Start on some steel where the puddle control is much better until you can get some really nice beads going, then switch to aluminum.