General welding questions, input appreciated

[james051]

Hi,

I started TIG welding about three months and now that I’ve got a little bit of experience under my belt I’ve got a couple questions that I haven’t been able to find an answer to here on the forums. I’ve spent about 50 hours TIGing steel (generally .028-.095 thickness material) and about another 50 on aluminum. I apologize if these questions are overly basic or already elsewhere on the forum (I’ve done several searches but haven’t come up with much). Most of the welding I’m doing is on a Miller Syncrowave 200. I don’t have any pictures at this time, but I will try to get some. I recognize I’m asking a lot of questions with one post, but I would be more than appreciative if you could answer even just one.

1.) In regards to TIG welding steel, I’ve noticed that sometimes my bead comes out very dull grey and sometimes it comes out shiny/metallic looking, aside from the color I can usually keep all of my welds looking pretty nice and consistent. I haven’t been able to isolate any difference in my welding technique that leads to the difference. Is one better than the other? If so, what is the correct way to achieve it?

2.) Aluminum-I’ve read a lot of material on the miller site and other web sites that clearly say you should use ceriated, thoriated, etc electrodes ground to a point when welding Al on AC with an inverter based machine, however I haven’t found a clearly stated answer as to what to use on a transformer type welder such as the Syncrowave.

3.) A common problem I’ve found when I’m welding aluminum is that when I make the first tack on the piece I get some contamination around the tack no matter how well I clean the Al. After I establish the tack and lay out the bead I have no problems with contamination (unless I dip the tip ). I was thinking I’m getting this contamination because the gas doesn’t have a chance to surround the weld before the arc starts, but as far as I know the Sync doesn’t have a preflow option. Any suggestions on this?

4.) Aluminum filler rod-I was practicing one day with some .033 6061 T6 and some 4340 rod. I later found some 5356 in the shop and found I was consistently able to produce a MUCH nicer looking bead with it than the 4340. Ive spent some time on Google but I haven’t been able to find much info on when to use which type of filler rod, other than the generic “4340 is a good general purpose rod”.

5.) Most of the work I’ve been doing /practicing on is thin 6061 aluminum. I’ve been having a **** of a time preventing the thin pieces from warping when I weld them. This really becomes a problem when the pieces are at angles that are difficult/impossible to clamp and then when they warp that nice tight joint I had spreads to a very difficult to weld .125 gap. Would preheating help this problem?

I would greatly appreciate anyone’s input to these questions or any other TIG welding general advice. Thanks for you time.

[fabricator]

well james to answer a few of those,first your beads shine will depend on how much time it has to cool while being sheilded with argon before air hits it. ( longer the purge the more shine it will have) so perhaps the dull looking welds may be from already being heated from a previous pass,allowing more time to cool down.or maybee you were going a tad bit slower with your pass,or had a little more heat.anyways it does not affect weld quality.
on the tungsten not sure but i believe lanthanated is perferd by most.im still old school and use (green banded) pure tungsten.but will try lanth when i use them up.
never used a syncrowave,so i dont know what to tell you about that,but usually its from electrode contamination, does it do it with a cleaned one?
4043 is all i use ,its pretty much an all purpose filler,5356 makes a little more shiney bead,and is a little more harder wire.
welding thin anything will cause warping.just have to try different methods,more tacks,skipping around,smaller beads,clamping,stress relieving,bracing,ect...

[Samurai Dave]

Question #1
I think Fabricator has you on the right track. I too noticed some welds come out shiney, and others dull. I like shiney.

Question #2
I have found that for aluminum on a transformer-based machine, Zirconiated worked great. On inverter-based TIG rigs, Lanthinated works great, for me. I tried Zirconiated on my Dynasty 200 DX (inverter-based) and the arc wasn't as stable as it was on the transformer rig at school. I researched as much as I could and found varying opinions. Fiinally I decided to just experiment. As with most things in welding it boils-down to just trying several flavors of electrodes yourself and seeing what works for you on each machine.

Question #3
Probably is a preflow (or lack there-of) problem. Other than using a seperate Argon line to feed gas to purge the area prior to striking an arc, don't have a solution. If there is a preflow option on your Syncrowave that can be an add-on, buy it. If there is a preflow function not operating properly, it would be nice to have it fixed. (Perhaps some Syncrowave owners can comment on their rig's options and features.)

Question #4
The 5356 rod is harder, so perhaps you can control the flow of it a bit more, which might account for your beads having a better appearance. It is also the rod to use if you plan to anodize your aluminum project. Using the 4340 for anodizing will turn all weld beads black, which could be the visual effect you are after, but not usually the case.

Question #5
Warping on thin material is always a pain. The best solution is to stitch some tack welds, about an inch apart (or closer if needed), along the seam. That will keep the metal together, so it warps together.

[Laiky]

#3:

Tap the pedal before starting the weld to initiate postflow, and purge the area. give it 2-3 seconds of flow then start your arc and tack.

[Dustyhaze75]

syncrowave .................................

I own a syncrowave 250dx ................
I use pure tungsten and 4043 rod unless I'm going to anodize the part. like dave said, If anodizing then use 5356. I haven't tryed using zirconiated. let me know how it works out for ya. I was talking to a guy that said once he used 4043 on an anodized part, he said the black around the welds were easy to remove/wipe off. not sure thoe...........I haven't tryed it. why would I, when I can just use 5356 ...lol. On my syncrowave there is no actual pre flow nob or dial but it does have a pre flow feature. the pre flow feature is factory set in your machine. give your pedal a quick tap and you should hear the pre flow. read your manual. if you go into your computer on your machine you should be able to change it. the factory has pre set 13 pre flow times for you to choose from. 0.2, 0.4, 0.6, 0.8, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 .................................................. .................
to change pre flow time ...........turn power off. push and hold process control button and turn on power. hold button for approx. 7 seconds (or until software version number _ _ _ _ _ _-_ clears meters)
the TIG LED will light and the meters will display [0.4] [sel]. the factory pre flow default setting is 0.4 seconds. to change pre flow time, press and release process control button until desired time is displayed on meters. hope this helps you out ..........................

[FusionKing]

Also 4043 turns black when the part is anodized AFTER welding... not welding anodized material. Just wanted to clear that up.

[james051]

Thank you all very much for your input. I had some time to play around on the welder today and experimented with the different filler rods/balances etc. I had better luck with the preflow problem today; I noticed that the contamination was the worst when I first started welding or after I stopped for awhile. Im attributing this to the gas escaping from the hose during the period of inactivity and not having a chance to reflood the area until a hair after the arc starts. I'm going to try adjusting the preflow time on the welder tomorrow, so I'll see how that goes.

After more practice Id agree that the reason I'm having a harder time with the 4043 is because it is much more fluid like, and thus I dont have the skill yet to perfectly time the addition of the rod to the weld.

I'm going to pick of a variety of electrodes pretty soon, so I'll keep experimenting on the different types. Also, one other question. I read on some random google site that using Thoriated electrodes can contaminate aluminum, does that sound accurate? (it was a pretty trashy looking website, so I'm rather weary of the info on it). Also on the line of thoriated electrodes, is there any application where these tips are prefered over any of the other types? I ask because I've read the cautions about thorium being radioactive, yet my shop stocks exclusively thoriated and pure tungsten electrodes so I'm wondering what the reason is to even buy electrodes that could be hazardous.

Thanks again

[Dustyhaze75]

ya, thoriated tungsten will contaminate aluminum. for metal use 2 percent thoriated tungsten and for aluminum use pure tungsten. aluminum contaminates easily. make sure you use a stainless steel wire brush to clean, I also use 3M pads then wipe it with some acetone or something to degrease it. have designated grinding wheels for each type of tungsten, dont use them for anything except for sharpening your tungsten and dont mix them up. for ex. don't sharpen pure tungsten then go and sharpen 2% thoriated tungsten on the same wheel. also, make sure your transition insulator(the white plastic part on your torch) is sealed if your using a gas lens for aluminum. tighten everything up and make sure its sealed and not loose. if it's loose it can create like a vacume. what's your regulator set at?