3/8 aluminum plate

[piersonrd]

I have a new 200DX and learning to weld aluminum
most thickness being 1/8'' but there is one weld i would
like to make its 3/8'' X 3 aluminum plate to 3/8 X 3 aluminum plate 3'' wide T joint. Can this welder handle this job, Im pluged in to 120 /30amp now but have plenty of juice avalible including 3 phase if needed.

Thanks for any help

[Bob Sigmon]

I'm new to welding and I've never come near 3/8 aluminum but Hawk will see this and let you know if it is possible and the best technique.

Your ability to reach the highest amperage on the 200DX is with 3 phase.
Here's the chart from the Miller info page.

[KB Fabrications]

I have a new 200DX and learning to weld aluminum
most thickness being 1/8'' but there is one weld i would
like to make its 3/8'' X 3 aluminum plate to 3/8 X 3 aluminum plate 3'' wide T joint. Can this welder handle this job, Im pluged in to 120 /30amp now but have plenty of juice avalible including 3 phase if needed.

Thanks for any help

Welcome to the forum. You will get lots of good info here.

You will most certainly max out the 200DX's capacity and then some trying to weld 3/8" AL, esp. with pure argon. Even if you use an argon helium mix I think you would be hard pressed to pull it off. The general consensus is 1/4" AL for the 200DX. Even then you may need an argon helium mix to achieve your desired results. HAWK will certainly be able to give you even more detailed information regarding this topic and you can also do a search.

Again, welcome aboard!

[Scott T]

If I understand, you have two pieces 3x3x3/8 and you want to weld a T-joint. Then you will have no problems, the material may seem thick but the overall mass of the weldment is so small that it will give you no problems. Scott

[Mike W]

I welded some 7/16 aluminum with a Syncro 250 set at 120 amps just to see if I could do it. The pieces were a few square inches each. Once I got started, it went ok.

[HAWK]

piersonrd,

Welcome! It can be done, but is really pushing the machine. Even with a small weldment mass the D200DX will have a hard time with inputting enough heat to do the job adequately.

If you want to do it, here is how: Input power needs to be at least 1 phase 220VAC. The 110 VAC won't get it for this. Machine set to AC, A 75%helium/25%argon mix @ 20CFH, 150 HZ arc frequency, 70-75 EN balance, 3/32" filler. A 200-300 degree F preheat will really help. A CCW swirling of the torch will quicken the puddle formation. Once established add filler and swirl the torch over the newly added filler to help wash in the weld toes. Watch your duty cyle. Don't burn up the machine.

[Blown S-10]

what is the piece being used for ? i have welded 1/2 3/4 and 1" with relative ease. but i didn't get full penetration, nore did i need to. the welds are pretty strong though.

[piersonrd]

I knew when i bought the 200dx, a project would
come up requiring the 300dx maby Miller will give
me a good deal on a trade in I only have 2 hours
of welding time on the 200dx. but back to the task
at hand ,I would like a good penatration of the weld
bc.it is a structural part, but if it fails it will only hurt
my feelings. Would the 3 phase be any better than
single, and when you say, Watch your duty cyle. Don't burn up the machine. does that mean stop, when the fan
comes on and continue, when it stops ?

PS maby i should swap machines before I try
this 3/8'' aluminum plate weld

Thanks for the help.

[HAWK]

I mean don't have the arc on for more than 2 minutes, then let the machine cool for 8 minutes. Wear some thick gloves with an air cooled torch as it will be very hot!

Most dealers are pretty sympathetic and should take back the D200DX as long as you buy the D300DX from them at the time of return. If they won't do it, then you may have to call the local Miller rep. Usually these things can be handled. If you are going to trade up, don't do the 3/8" until you get the 300. The D300DX will blow right through the 3/8" fillet with ease on argon.

[Scott T]

Hawk If I'm correct on the size of the weldment, you are still saying that a 200dx will not weld this properly running straight argon without preheating. Hawk I have read many of your posts and have great respect for your knowledge and honesty but I have trouble agreeing with you on this one though. I honestly think this would be a walk in the park. Scott.

[KB Fabrications]

Hawk If I'm correct on the size of the weldment, you are still saying that a 200dx will not weld this properly running straight argon without preheating. Hawk I have read many of your posts and have great respect for your knowledge and honesty but I have trouble agreeing with you on this one though. I honestly think this would be a walk in the park. Scott.

Scott T,
I think what HAWK is saying is that it IS possible to do this. Go back and read his initial post. However, you are pushing the machine up to and past its limits. If you feel like that is a good idea then by all means go for it. I personally would have a hard time recommending that someone push their equipment over its rated capacity, especially in the presented scenario.

I have used my 200DX to weld 1/4", at 200 amps using pure argon, with a little preheat and it certainly COULD do it. That said, the fan cycled almost continuously and it was clear that I was at the limits of the machine. If you do this on the 200DX on a regular basis then you risk damaging the machine, bottom line. I think that is the point HAWK was trying to make.

So if you feel comfortable advising that someone do this then, like I said, by all means go for it. I personally don't feel like that kind of advice is appropriate for someone learning using a brand new machine. Just KPO (Kevin's personal opinion).

[HAWK]

Scott T,

It is no "walk in the park" from my personal experiences. I have welded 1/4" square tube to 1/4" with the method and parameters I listed using a D200DX. It was a struggle at best. It was a considerably larger weldment than 3/8"x3"x3" weldment being described.

More on par with the specific example at hand I have welded a T-joint using 2 pieces of 3/8" x 1.5" x 6" 6061T-651 aluminum plate. I think the actual weldment mass is nearly equal to the T-joint in question. Once again even with a 250 degree F (recommended interpass preheat) and the raised input wattage from the 75% helium/25% argon shield it was a tough weld to make.

Can it be joined? Most definitley. Can it be welded with adequate penetration for a structural weld? From my experiences the answer is no.
Please remember I have spent considerable time with the dynasty 200 and 300 in the DX models. They are both great machines. The fact of the matter is the 200 simply does not have the juice to do what piersonrd is wanting to do.

This job is a walk in the park for the D300DX. Please see attached. The 200 is a great machine, but it is simply not going to do this.

[HAWK]

Scott T,

Thank you for the respect. I am glad you are enjoying my posts. I appreciate your statement that you disagree. This being said I invite you to make the 3/8"x3"x3" T-joint as described with a D200DX running AC polarity with any input power, shielding gas, and other parameters you wish. Let me know how turns out.

Now if wish to depart from standard welding practices and procedures, then I can assure you this weldment can be made with the D200DX at a cost. There is a very high cost associated with required materials to do it. There is also a great skill level involved. It is certainly not for those learning to TIG. It is more for seasoned TIG welders who have a genuine need to penetrate a large thick weldment for a particular requirement. It is neither easy nor inexpensive. I am talking about signifigantly increasing the input wattage through welding polarity and certified ultra high purity shielding gases.

[piersonrd]

Well don't know about swaping the 200DX for the
300DX but in the meantime im going to run new
wire to my welding area about 40ft from one of the two
incoming main 150amp 3 phase service boxes
think i'll run 4 wires in 1" conduit just in case i deside to run the welder on 3 phase ,What size (wire and breaker) will i need for the 200DX or the 300DX If I swap?
And does anyone recomend 3 phase over single?

PS May just sub out the 3/8'' thick job

Thanks for the help guys

[HAWK]

piersonrd,

3 phase power is nice. Your power consumption will be less on 3 phase. Many inverters will have an increased duty on 3 phase input power since the input bridge and filter caps do not have to work as hard as on 1 phase. The arc qualtity on the inverters will be the same on 1 or 3 phase. If I had it, then I would use it. I recommend consulting your owner's manual and/or an electrician for this information.