Need some advice with .065 aluminum sheet

[KartRacer55]

Hey everybody, long time no post.

I have a few projects I need to tackle (Namely an aluminum fuel tank for a FSAE race car, proprietary design so pictures will follow at a later date), and I need some help. I have done a ton of work with .125 and don't seem to have much of a problem, even with material slightly thinner, but .065 is new for me.

Using a Dynasty 200DX, 100% pure argon. At the moment, Im using 3/32 filler, and have been using 2% thoriated (I enjoy the radiation), no but seriously, I wasn't liking the 100% tungsten. Unfortunately, at the moment, It is the only size tungsten I have available, in a few days 1/16th tungsten will arrive.

Machine is set on AC, 75 amps, 40% on the balance, Pulse is on at 60hz, HF is set to 200hz.

Im sure these settings are way off, but I was messing around with it, and this is where I seemed to get the best results, but again, I didn't try every combination. I was wondering if you guys could point me in the right direction for welding "open" corner joints? I can't seem to get a really nice bead, its more like a mushy bead with out any nice definition like my "practice" beads had on flat plate. Any tips?

Also, I am having a **** of a time tacking and getting the beads started. When the beads are started, I can manage the puddle and keep it from dropping out, but I am having a heck of a time actually getting the two pieces joined initially, It seems like if I try and get heat in one piece then the other and back and fourth, neither puddle is molten and the filler ball-s up on me. If I try and hold heat on one side and add filler, I can get it to build up on top, but have a problem getting the added filler to join to the other piece!

Any advice? This is seriously difficult! Been working for about 4 hours with this material trying to get the machine dialed in and perfecting corner joints and, like I said, getting the beads started is a pain, but the good news is, when I get them running, they are strong and air tight.

Any tips from you guys would be great!
thanks
Jim

[Pangea]

I get the edges just molten, then lightly gag the tungsten to make the puddle join. I tack the whole thing this way then clean the tungsten and go to work welding. Sharpen that big tungsten and leave the tip with a small flat spot. It will make its own ball as it needs it. Try chasing your filler wire instead of dipping. There is no shame in this though some welders act like it's a sin.

Sundowner III seems to know a lot about welding sheet metal tanks from reading his past posts. Ask his opinion and use his experience too.

Good luck.

[B_C]

I chase the filler a lot on LONG seems....Because you can leave the filler in the GAS which makes for a cleaner weld and mostly because it's fast

[KartRacer55]

Thanks guys.

Do those machine settings seem about right?

By chasing the filler I assume you mean move the puddle into the filler, as opposed to dipping the filler into the puddle?

[B_C]

It means keeping the filler rod against the joint and just melting it as you move down the joint...."Chasing it" not dabbing...

[SundownIII]

KartRacer,

First, let me say that I suspect that BC has considerably more aluminum tank building experience than I'll ever get. But yea, I guess I've built my share.

In addition to the comments Pangea and BC have added, I'll ask a few questions and make a couple comments.

First question is why was .065 material selected for this tank. Is the tank very low volume? Was it designed with baffles which could be used for reinforcement? Is it some odd shape, or basically a rectangular cube? How is the tank going to be mounted/supported?

Now back to your settings.

Amps seem to be OK. I tend to like to run a little hot (faster puddle) and back off the pedal as the material heats up.

1/16" tungsten will allow you better control of the arc. BC likes the thoriated. Personally, I prefer the lanthanated (2%). Material should already be clean (make sure it is). That said, I'd increase (on the Dynasty) the balance to between 70-80%. It will give better penetration and help save the tungsten on that setting (more DCEN vs DCEP).

I didn't understand your comment about having the pulse set at 60HZ and the HF set to 200HZ. Did you possibly mean you had the pulse set at 60PPS? Regardless, try turning the pulse off. The HF set to 200HZ also didn't make sense. Were you possibly referring to AC frequency control? If that's what you were talking about, then I'd say it's a little high. I'd recommend a setting of about 120 HZ. A higher setting will concentrate the arc (tighter), but you don't need that for the weld you're trying to do.

I've found that most times I can start a puddle on one edge and then drag the molten metal over to the other edge. If that doesn't work, a quick dab of filler will generally flow the two edges together. Make sure you get adequate filler in the joint. Aluminum likes filler.

Chasing the filler is a technique the old (just joking BC), experienced tiggers use. Takes a degree of practice to get the timing down. Generally yields a faster weld with less heat in the surrounding metal. Also generally has a slightly flatter (less stack of dimes) look. Excellent process if you can get the timing down. Generally done by welders who "run hot and run fast".

Get back to us on those questions and we'll go from there.

PS. Went back and reread your post. Are you holding too long an arc. Common mistake many make. Too long an arc will heat (not melt) the surrounding metal, melt the filler, and not allow you to properly direct the heat where it's needed to establish and flow the puddle. Just another thought.

[FusionKing]

Yep settings are off a good bit IMO.
I would START with the balance about 68 and hz around 60. An outside corner joint likes settings more in the opposite direction of the inside corner joints. My goal would to be having a nice smooth soft wet arc for this. Once you get going you can make small adjustments as you go.
I probably wouldn't use pulse on this.
I would maybe even use sign wave as well otherwise I would use soft wave.
If you don't have the wave shaping then I would try slight hz adjustments during the tacking process to see how smooth it welded.
You will need tacks as close as 2" or less all over before you weld this up or it will warp. Lay the cup right on the joint and slowly rock it over and tack.
The trick is to get the parts to contract together instead of expand apart.
Make sure the pieces only touch at the very inside and no overlap. I normally use a piece of angle clamped inside to begin with.
Take the time to make it fit perfect so the weld will go right into the "V". If it gets off then stop there and correct your fit-up or it will be wavy when you weld it. You can use a body hammer and lightly tap the direction needed when hot from the tacking also.
I would not have any problem using 3/32 lanthanated with this. Get rid of that pure (100%?) tungsten, it is trash on a Dynasty. Ceriated or lanthanated on aluminum.
It would be a toss up whether or not to use smaller filler. I would generally use 1/16th for tacking and 3/32 to weld it. .065 just really isn't all that thin to work with really, just thin for a fuel tank. Move around a lot when welding so it can expand and contract a little more freely without getting locked in a warped state. I like to weld a bead a few inches and then move to the total opposite side. When I come back I pick up where I left off so you can't tell I stopped.
I don't mind chasing the filler either but if I am going for looks I would much rather lay dimes...esp with a Dynasty...they can lay it nice IMO
If your smart you will play with some scrap and make some outside corner joints and set your machine before you lay down the long beads... until you get familiar enuff to just know how to set the thing up from exp.
If you do this right it will weld perfect without hardly even using filler for tacks and you can even weld it only using filler periodically, but I would use as much filler as possible without making the bead too high because it IS a tank.
BTW, I'm assuming this is 5052 and you are using 5356 filler.
If you was doing this all day then your settings would begin to lean more to the higher hz etc. but doing one off fab work and just getting the hang of things You would be better to stay a little more conservative in my opinion.
HTH

[SundownIII]

KartRacer,

I would give a lot of credence to FusionKing's comments, particularly with regards to the frequency settings.

BC and I both use transformer based machines which are, by their nature, limited to operation at 60HZ. Most of the aluminum welding I have done with other that the Sync 250 was with a Dynasty 300. I've used the 200 but can't say I've done outside corner joints with one. FK has.

The reason I had recommended a higher HZ setting (120) than FK recommends, was based on the comments you made about having difficulty tacking the parts. A higher frequency setting will give you a tighter arc and better allow you to direct the heat exactly where you need it. With that said, start at 60HZ and work up to where you're comfortable. Everyone needs to find their own "comfort zone".

I will say that doing inside corner joints, you'll find that a HZ setting around 200 will give you a nice tight arc, which helps with the root penetration.

You've got some different base settings to now try. Give it a whirl and let us know where you ended up.

[B_C]

KartRacer,

First, let me say that I suspect that BC has considerably more aluminum tank building experience than I'll ever get. But yea, I guess I've built my share.

In addition to the comments Pangea and BC have added, I'll ask a few questions and make a couple comments.

First question is why was .065 material selected for this tank. Is the tank very low volume? Was it designed with baffles which could be used for reinforcement? Is it some odd shape, or basically a rectangular cube? How is the tank going to be mounted/supported?

Now back to your settings.

Amps seem to be OK. I tend to like to run a little hot (faster puddle) and back off the pedal as the material heats up.

1/16" tungsten will allow you better control of the arc. BC likes the thoriated. Personally, I prefer the lanthanated (2%). Material should already be clean (make sure it is). That said, I'd increase (on the Dynasty) the balance to between 70-80%. It will give better penetration and help save the tungsten on that setting (more DCEN vs DCEP).

I didn't understand your comment about having the pulse set at 60HZ and the HF set to 200HZ. Did you possibly mean you had the pulse set at 60PPS? Regardless, try turning the pulse off. The HF set to 200HZ also didn't make sense. Were you possibly referring to AC frequency control? If that's what you were talking about, then I'd say it's a little high. I'd recommend a setting of about 120 HZ. A higher setting will concentrate the arc (tighter), but you don't need that for the weld you're trying to do.

I've found that most times I can start a puddle on one edge and then drag the molten metal over to the other edge. If that doesn't work, a quick dab of filler will generally flow the two edges together. Make sure you get adequate filler in the joint. Aluminum likes filler.

Chasing the filler is a technique the old (just joking BC), experienced tiggers use. Takes a degree of practice to get the timing down. Generally yields a faster weld with less heat in the surrounding metal. Also generally has a slightly flatter (less stack of dimes) look. Excellent process if you can get the timing down. Generally done by welders who "run hot and run fast".

Get back to us on those questions and we'll go from there.

PS. Went back and reread your post. Are you holding too long an arc. Common mistake many make. Too long an arc will heat (not melt) the surrounding metal, melt the filler, and not allow you to properly direct the heat where it's needed to establish and flow the puddle. Just another thought.

Probably a Typo....I use pure thungsten with AC......Thoriated with DC

[B_C]

Hey I'm only 60 give me a break.....Hey that reminds me I haven't had Breakfast yet...BCing U

[SundownIII]

Hey BC,

I was always taught I could call my "juniors" old guys. I'm 61.

Man that pure tungsten is "old school". PM a mailing address and I'll send you a couple sticks of lanthanated to try out.

[KartRacer55]

Thanks everybody!

Im going to be back in the shop early this week to give it a shot.

BC and Pangea, thank you for the tips. Im definitely going to try chasing the filler out as soon as I can figure out the machine settings. I think that is one of my biggest problems so far.

Sundown, yes, I did mean 60pps. Couldn't remember the lingo. As for the tank, it is a low volume tank (2 gallons) and it was designed and simulated by several M.E.'s here at Rutgers, but with have several odd bend's in it. It will have some internal baffles which are designed to minimize my welding but also to work with the overall design of the tank. I would personally like some thicker aluminum, but we can't always get what we wan't, so here I am struggling! haha

Fk, Thanks for the Info and set up tips. I have been doing several practice pieces, and the hardest part for me is actually tacking them together. Once I can actually get a few good tacks, the beads run fairly well, althought they do not have the nice stack of dimes look I would want my name tagged on to. Team leaders were impressed with the practice welds I did, definitely better than the last few years tanks were, and these are definitely leak proof, but I am still not happy with the appearance, which I will be working on once I get the machine set up correctly.

To All, thank's for the advice. Like I said earlier, I was completely guessing on all of the settings. Needless to say, this machine is far more adjustable than I am capable, because I learned to weld on an old school Linde UCC-305. A MAJOR leap in technology and variables on the machine.

As for the tungsten, the 1/16 will arrive soon, but I do not know off hand what was ordered for me. I believe it will be lanthenated though.

[Broccoli1]

How the heck are ya Jim?

You bang yer head a little too much going round the track?

Back in October I linked the Miller Tig Handbook when ya asked about favorite Filler & Tung- didn't look at it did ya

Chapter 6
Figure 6.3b Aluminum with Advanced Squarewave weld parameters.

hmmmm

lookee dat

Suggested settings for 1/16th Aloominum.


Have a good 2009

[B_C]

Hey BC,

I was always taught I could call my "juniors" old guys. I'm 61.

Man that pure tungsten is "old school". PM a mailing address and I'll send you a couple sticks of lanthanated to try out.

I have heard that from a couple people....Does it "Ball up" ?

[SundownIII]

BC,

Depending on size/amps it will generally form a small ball on the tip. Nothing like the ball pure forms though. Arc remains very controlable. I've tried using thoriated for AC before, but the tip of the tungsten seemed to want to want to sort of split. Thoriated seemd to form a ball but the outside of the tungsten kinda looked like a stick rod that the flux didn't burn off evenly. I've had really good luck with the lanthanated.

Buddy of mine at the LWS gave me a couple sticks of zirconiated to try. Says I'll like it. Haven't gotten around to using it yet though.