3/8th Aluminum with my PM205

Making a cupola for a pizza oven I am building. I may have bought material that is too thick for my 200 amp tig welder. I have an Everlast Power Master 205. I have been happy with the welder but I have a few questions to see if I am on the right track for this fabrication job.

I don't think I am getting good enough penetration on my work. I have been canceling out pulse as I need all the amps I can get out of this unit for this thickness. My settings usually are around balance 30 percent and Freq at 100. I use my foot pedal with aluminum but testing is showing I may get more power with my finger control....maybe I can nurse my amps by cycling on and off with my finger switch if things get too hot after my bead gets going?

I think the extra frosting I am getting at the edges of the weld are mostly as things are not quite hot enough. If I turn my balance to max penetration and the freq up even higher will this get me a bit closer to the penetration I need. I also am thinking of clamping my work up off the table as maybe the 1/4" plate steel surface of my welding table is steeling heat from my work.

I realize a mix of helium would help but at this time I am not able to find the cash for this outlay. Not sure if the pictures show but I have ground out a V for the butt weld to help with the penetration as well.

I realize the front side of this should be welded as well but I am going for a clean no weld look. As it will house a smoky vent for a pizza oven the unit will be painted black because of the smoke that will discolor it anyways. Since it will be painted I guess I could sand a bit of a V joint at the front side and weld and then sand to kind of reinforce things as well.

Thanks for any help on this one.....if anyone is interested to see the pizza project build and also a model of the cupola I am building feel free to visit this link.... https://picasaweb.google.com/waynebe...42PompeiiOven#

Could be the frost is from needing more cleaning adjustment in the balance. Try preheating first and adjust the balance for more cleaning. If you preheat a piece of steel as well, the steel will help keep the aluminum warm while welding

What size electrode and filler rod are you using?

You can preheat the metal.The table definitely is a heat sink. You also need to add the clamp directly to the metal. But I would say the problem is that you haven't properly prepared the joint with a full V. Reduce your cleaning to 20%, or until the cleaning lines narrow way down.

Yes, what tungsten and filler rod size, and type are you using? Are you pointing or balling the electrode?

Thanks so far guys.......

1.Mark I am not sure what you mean "add the clamp directly to metal"?
2.I was a bit reluctant to get too close to the finished side of the unit with the V in case I got burn through but maybe I should go deeper. I have ground my V joint about 3/16th deep so about half way.
3.I am using 1/8th red electrode and grinding to a bluntish point not a sharp point with all the amps......and not a balling it for sure. Rod is just under the 1/8th size I guess its 3/32nd.
4. What about the idea of frequency way up. I normaly dont do this but I though I read somewere its will focus a tighter arc. If I go with high freq say 200 and move over the middle of the joint quickly and slow the moving of the torch down on the sides where the metal is thicker may help?
5. What about the feeling I have with the trigger giving me more amps than my pedal? It may just be my imagination but it seems like the trigger has a bit more get up and go with similar maxed out settings?
6. Also I have turned up my argon about 20 percent higher then my normal 125 amp settings that I weld with. I think I read somewhere to turn up argon with more amperage?........thanks and sorry I have so many questions all in one post here.

In stead of clamping your clamp to the table, it should be clamped directly to the piece. I am assuming by the fact you had the metal flush with the table, you did not have it clamped directly. You might try going up a size in tungsten to 1/8", as 3/32 may not be able to deliver the power. The frequency will pinpoint the arc, but on thick metal, I find a broader arc can get things hotter faster. Pausing on the sides is the only way you will be able to get the heat in. Once you get a puddle, you are going to have to hold off from adding the rod until it gets further down. Now, proper technique demands that you get 100% penetration on this type joint. That means you will weld through the metal, with a bead on the underside like you have on top. Really a root pass is in order, with at least two top passes to fill. You don't usually weld joints like this in one pass, as it yields poor quality welds and does not allow time for impurities to float out before it cools.

Sorry Mark I am stiill not sure what you are saying about the clamp. Are you talking about the ground clamp or my clamps for holding the work in place so it doesn't move and twist. My clamp for holding things in place is directly on the work holding the work firmly onto the table. If you are referring to the ground clamp I will move it to touch the work piece.
As mentioned my tungsten is 1/8th, its the rod that is 3\32.
Point taken on the frequency I will leave it on around 100.......thanks for that.
I will have to admit I have never done a root pass with two top passes to fill. This is my first kick at thick aluminum so I should probably learn more about the basics and make sure I am aproaching this right. I am learning as I go I guess and I do apprectiate your help. .........wayne

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Originally Posted by www

Sorry Mark I am stiill not sure what you are saying about the clamp. Are you talking about the ground clamp or my clamps for holding the work in place so it doesn't move and twist. My clamp for holding things in place is directly on the work holding the work firmly onto the table. If you are referring to the ground clamp I will move it to touch the work piece.
As mentioned my tungsten is 1/8th, its the rod that is 3\32.
Point taken on the frequency I will leave it on around 100.......thanks for that.
I will have to admit I have never done a root pass with two top passes to fill. This is my first kick at thick aluminum so I should probably learn more about the basics and make sure I am aproaching this right. I am learning as I go I guess and I do apprectiate your help. .........wayne

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Yes, put the ground clamp (technically the work clamp, I believe) directly on the work piece. Cool project, by the way.

Yes, You are loosing a lot of power through the indirect contact. Think about it: Aluminum oxide resists the flow of electricity. What is the surface of Aluminum comprised of? Aluminum Oxide. Make sure your ground has a shiny area as well. You should gain a few amps that way. Also check your work clamp. IF you have another work clamp you can double check the power delivered by the clamp, it would be good too...Or just swap it out to a larger one.

Move a few of the bricks under the table up to the top of the table, and clamp your pieces to them to insulate the part from the table, reducing how much heat gets sucked out of the part. Clean an area of the aluminum and put your ground clamp directly on the cleaned area. Clean the joint very well with a stainless brush. Preheat the parts with a propane torch or similar to get them much hotter than room temperature. Increase the "vee" depth adn make a smaller bead size (the melting of the rod to make a large bead takes alot of energy to perform).

John

Thanks guys great tips! Nice bike John by the way, I cant really clamp to bricks John as this is a six sided vent for the gazebo that needs to be jigged to flat stable material to keep things from twisting and what not. As it is its going to be tuff to keep things flat and square. These issues in them selves are a whole nother thing I am not super sure on. I have noticed that my first 3 piece unit (shown in pics) that I welded up grew from 15" to 15 1/32" in width while being welded and then shrunk back after cooling to its original width. What I am trying to get my head around is I clamp it firmly to the table to keep the 3 pieces flat and square to each other but the whole unit kind of grows on me while welding. I am trying to clamp closer to the weld area and just doing one side at a time so the part that wants to grow is somewhat free to do so with out moving my clamps too much. Kind of learning as I go here as you can probably tell.............wayne

On my machine, the digital display will read out the amps it is welding with (or "trying" to weld with in stick mode) with. If you have a stick welding mode, switch to it and you can see the amps the machine is trying to put out without actually having to light an arc. From there you can see what current you are getting with your footpedal at WOT ("wide open throttle" ;) ). A footpedal adjustment may be necessary to get 100% output at WOT, or certainly the torch switch could be a useful option on a project like this.

You can certainly regulate power with the torch switch, just set some downslope and upslope delay and by cycling the torch switch on and off manually, you can regulate the output current to below the full depressed setting. (Or just increase your travel speed when necessary.)

In tig mode you can also reduce your tungsten stick-out, prop the torch on an angle on its cup on a piece of scrap, and strike an arc while looking at the machine display, and see what the display is reading.

I've done some 3/8" aluminum welding with my 200 amp machine, and travel speed is going to be really slow (and penetration not very deep) on one welding pass without any pre-heating. Hopefully your machine and torch are up for the duty cycle required by running them "flat out" for minutes at a time. This will be the test. It will also be like a physical endurance test for the welder (a sort of "TIG yoga" ;) )

Pre-heating will allow quicker travel speed and lower duty cycle by your machine and torch to weld the joint, maybe a little deeper penetration if desired. It looks like you are doing OK to me based on the pics, if you just beveled a little deeper and built the welding bead up a little higher with a subsequent welding pass, you'd have a stronger weld joint. Also select a filler rod if otherwise acceptable, for high strength weld deposit (So if this is 6061 you are welding, 5356 would give a stronger and more ductile weld deposit than 4043.)

Otherwise you could switch your joint design to being welded on both sides, and ensure full penetration. But it sounds like since that would require either finishing the weld bead, and looking at it on the other side, its a design decision up to you.

If you wanted to try pre-heating this, I would recommend a BBQ propane tank powered "weed burner" torch (around the order of 300k BTUs). It would heat it up in a jiffy.

There is no problem with the frosted look it, that is just the result of the cathodic etching of the cleaning A/C action when welding aluminum with a low travel speed. I would think you could make either a 3/32" tungsten or a 1/8" tungsten work just fine on this. Definitely crank the A/C balance to "min cleaning" to maximize the welding power available. I would think higher A/C frequency might be useful for deeper penetration.

One of Jody's tricks and tips is to clean the piece where you plan to clamp the ground and instead of clamping the normal way, remove the ground cord from the clamp, strip 2" of insulation off the end of the ground wire, then clamp the bare wire directly to the work piece. That eliminates the resistance of the clamp and the bolts since the ground wire is in direct contact with the work piece.

http://www.weldingtipsandtricks.com/...ng-ground.html

Thanks guys. I have made some progress with grounding to the work rather than the table and clamping to spacers which lift my work off the table. Not sure if pictures will show my progress but thanks I feel like I am heading in the right direction anyways.

Jakeru, good tip on checking amp numbers with the head turn. I may find an assistant to help out on that one.

I am having a tough time with only welding one side of my work as when I let everything cool down and unclamp my work the two outer pieces welded to the middle part curl up a bit, its hard to keep it flat, maybe its because I am laying one huge bead in there all at once?

I would say that yes, laying a large, hot bead all at once will do that. You can either run multiple passes or negate the warping by prebowing the plate so that once the weld cools, it cools flat.

Mark I will try multiple passes as you recomend. Thanks for this!

Hello all,
Sorry for jumping in with a question on your thread WWW, but all the talk of cleaning vs penetration on the balance knob has me interested. I have the 250 EX, I am guessing the knobs are the same, Which way is cleaning and which way is penetration? Also does any one know if the arc force adjustment works on tig, or just on stick?

WaWelder,

I am not sure if you have, but if you haven't download the manual, please go to the website and look at the big red button on the right hand side and click manuals and download it.

If you look at the welder on AC balance, there is a + and - sign. The + is on the right. Positive polarity. The - is on the left. Negative Polarity. To increase cleaning, you add more + by turning it clockwise, toward the right. We are oriented as % + or % of cleaning action. Typically you are only going to need about 30% +.

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Originally Posted by WaWelder

Hello all,
Sorry for jumping in with a question on your thread WWW, but all the talk of cleaning vs penetration on the balance knob has me interested. I have the 250 EX, I am guessing the knobs are the same, Which way is cleaning and which way is penetration? Also does any one know if the arc force adjustment works on tig, or just on stick?

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Hi WaWelder
I am pretty sure the arc force adjustment is for stick only. Atleast that is how I read into what the manual is saying.............wayne

OOps. Missed that one. There isn't any value in arc force for tig really,and it is inactive for tig.

Making some steady progress. Finding it interesting to clamp this thing up. I am a hobby welder and this may be a bit out of my comfort zone in dealing with good penatration and controlling distortion. I have certainly got an array of jigs and what not to hold this thing together.

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Originally Posted by www

Making some steady progress. Finding it interesting to clamp this thing up. I am a hobby welder and this may be a bit out of my comfort zone in dealing with good penatration and controlling distortion. I have certainly got an array of jigs and what not to hold this thing together.

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I know what you mean about the clamping up, sometimes I just pray that I get the thing tacked up before anyone sees the spectacle. I have often thought of employing and training an octopus, for just such tasks.

Hi www, reading your post I'm not sure of your desired outcome in this respect: You mention not welding thru to the "finished side" of the project. So you are welding from the back side? In that case you do not want to penetrate completely? If that is the case then you you do not need 100% penetration, right. So you would only need to consider the structural requirements of the part itself, ie is the weld strong enough to support the parts. It may be that a shallow partial penetration weld is sufficient for what you have on hand. To be sure making a full penetratating weld on 3/8 aluminum is a little beyond your machine in a daily job sense, but you can get er done.

If you feel your single pass is not structuraly sufficient, then yes bevel a bit more, pre -heat is your friend. Dont worry about pulsing. The frosting is etching or "cleaning" so you need LESS not more. Wide etching is indicative of electrode positive, or a wide shallow bead profile (more heat in the electrode). A/C freq is fine around 60-100.
With pre-heated metal then quickly stainless brushed, lay down a root pass. You seemed to indicate some kind of "moving quickly to the center, and then to the sides", ..... ??? not sure if your thinking weaving or walking or something, but if your looking for deep penetratating pass don't move the the tungsten back and forth, travel in the direction of the seam only. No stick or mig circles etc. here. You can only make a weld bead so wide, so if you are not filling the valley, so to speak then you need a filler pass (many different names). This is where you can get fancy and weave a bit to spread the bead.

So unless this Cupola has to be very strong and or support a lot, you may be making it more difficult than it needs to be. Also sequence your welds to control distortion, sometimes large flat parts like that just need to be "coaxed" back to flatness after welding with some muscle! lol ! Sorry for the late post on this thread

Thank you Trackmaster.............good points. I will post some pics of the next stage of the design and fabrication as it gets completed. I think this new addition to the design of my mounting brackets will reinforce what I was worried about with the front part of the panels not getting a weld on its side. Hard to explain but the pics will explain further. I am no longer worried about the penetration. The grounding to the work helps and design issues will also get me to where I want to be for strength.

My feeling on the wide etching is if things are not hot enough during the weld this look will be more pronounced and that is what I was trying to get a confirmation on.

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Originally Posted by www

Making some steady progress. Finding it interesting to clamp this thing up. I am a hobby welder and this may be a bit out of my comfort zone in dealing with good penatration and controlling distortion. I have certainly got an array of jigs and what not to hold this thing together.

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That does not look like an easy one, and I can relate for sure.

For me that would be a hold it in place, look real good and hard at alignment, tack real light, adjust (most likely required), and weld it in. I think Robert might have said that in a different way. haha.

Mike would you have any tips for tacking aluminum while holding the work with one hand. I guess where I would be a bit stumped on something like this is without being able to add rod? I guess there is an ideal method for this so you don't just put holes in the work. The next post I make will show progress of what I need to do today on the project and its a 2" x 3/16" plate rim onto the top edge of the 3/8" main frame. It will need to be angled up and holding and tacking would come in handy. As I am not comfortable with the tacking with out using rod I will be making up some sort of a clamping jig I guess so I will post some pics later on if things go good.

You can tack without the rod, just be sure you weld overt op of the tack with the filler. An autogeneous weld (weld with just the base metal) can be done on many materials, but with aluminum, especially 6061, the weld will crack if it is not diluted with an appropriate filler alloy. That said, it will not hurt to tack it without filler, and then weld over it with filler.

With the thickness of the parts you are working with, you will probably be best suited to make a few very small tacks without filler, then go back over and make the tacks larger with filler, then go over with the actual weld.

John

WWW,
There are some nice assistants that you can buy. Bessey is a good company that has many adjustable clamps and jigs that help in hold about anything. Strong hand tools, is another. They first came into the market with knock Bessey clamps, but they have rapidly advanced into about any type holder, and clamp imaginable. If you need something held, you can do it with one of these "assistants". Not cheap but beats hiring someone to come in and hold it for you.

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Originally Posted by www

Mike would you have any tips for tacking aluminum while holding the work with one hand. I guess where I would be a bit stumped on something like this is without being able to add rod? I guess there is an ideal method for this so you don't just put holes in the work. The next post I make will show progress of what I need to do today on the project and its a 2" x 3/16" plate rim onto the top edge of the 3/8" main frame. It will need to be angled up and holding and tacking would come in handy. As I am not comfortable with the tacking with out using rod I will be making up some sort of a clamping jig I guess so I will post some pics later on if things go good.

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See Sportbike's post #26. You do not need filler to tack with the TIG, you can melt the 2 piece together. Go light in case you have to move it.

IME, autogenous welding on 6061 aluminum, including tack welding without filler rod, will give a really crack-sensitive weld. It only takes a small dab of filler to make a strong tack, but you'll need both hands free to do this.

It sounds like you could use a "third hand" (AKA "welder's finger") to hold your parts still for two handed (TIG+filler rod) tack welding. They are a huge time saver for jigging up small parts; see attached pic.

Cool project, good luck! I really don't like "reverse" bend parts for the post weld shape because it's so hit and miss. But, when I have a multiple run I will usually weld the first one up and see how much it moved, then adjust the others accordingly. There's always a little bending and pounding, but this limits the majority of it to the first piece.

The pictures shown here are what I was trying to explain for beefing up the design flaws with no weld on the face of the unit. This transition area will also act as an anchor for bolting the roof of the cupola to the frame of cupola. It is the same angle as the roof line of the cupola.