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Need some TIG technique advice

Posted: Sun Sep 27, 2020 9:31 pm
by johnnyv449
Hello everyone,

I'm trying to get better at TIG so practicing as much as possible. Let me give some context to what I'm working on. I might have the opportunity to open up a small business which is something I've wanted forever. I deal with boats so it would be welding stainless and aluminum. I've done aluminum in the past for my own boat but by no means am I a welder! It took some good welds, a lot of bad ones repeats and final polishing. I'm working on stainless as the business so i went back to carbon steel for getting the right technique.

I cant seem to find any schools around me that offer basic classes. The college programs opened but are all full. That said if anyone knows of any training on Long Island NY please let me know. I live on the east end of the island.

OK sorry for the long winded intro.

Here is what I have and need suggestions PLEASE.

Carbon Steel probably 1/8 to 3/16
Cleaned and buffed with a wheel
3/16 ER70S-6 Filler
2% Thoriated (red)
Argon 18 CFH
#8 cup (also tried #6 and #12 gas lens)

In the past I was able to do some aluminum weds like this (probably got lucky a few times LOL)
aluminum
aluminum
20190718_230925.jpg (26.9 KiB) Viewed 2135 times
Everything below is carbon steel.

This is 3/16 filler
reg 3-16.jpg
reg 3-16.jpg (14.66 KiB) Viewed 2135 times
This is 2 welds one using pulse. Both at about 90-100 amps max. The right one used a pulse setting at 60hz. The left was no pulse just moving the torch.
pulse and reg
pulse and reg
20200927_102532.jpg (67.36 KiB) Viewed 2135 times
I'm trying to figure out why I cant seem to get these to wet out and look cleaner. Any suggestions would be great. I need to have a person over my shoulder telling me the goods and bad so that I can go an practice but cant seem to find a class.

Also I had a few weld that popped holes in it. I figured that it was due to me welding on the same piece without letting it cool. What causes the weld to do this?
holes.jpg
holes.jpg (28.97 KiB) Viewed 2135 times
Any thoughts and knowledge would be great!

Thanks

Re: Need some TIG technique advice

Posted: Sun Sep 27, 2020 10:23 pm
by cj737
First off, reduce the filler size from 3/16; that huge! 1/8 is plenty, 3/32 probably even better.

With pulse, you need more amps, not less. Material .125, filler .125, probably nearly 140 amps. You mention Hz, but that’s a frequency not a pulse measurement I’m aware of? What machine are you using? Pulse is general Peak, Background, and PPS. I like 50%, 25% and 1.2 in that order.

Re: Need some TIG technique advice

Posted: Sun Sep 27, 2020 10:42 pm
by Oscar
cj737 wrote:First off, reduce the filler size from 3/16; that huge! 1/8 is plenty, 3/32 probably even better.

With pulse, you need more amps, not less. Material .125, filler .125, probably nearly 140 amps. You mention Hz, but that’s a frequency not a pulse measurement I’m aware of? What machine are you using? Pulse is general Peak, Background, and PPS. I like 50%, 25% and 1.2 in that order.
By definition, per second (1/s) is the unit of Hertz. The time unit of PPS is equivalent to Hz, because it's 'per second'.

One mistake is "cleaned buffed with a wheel". This is not sufficient to properly remove millscale. You need a hard grinding disc or a very coarse flapwhee. "cleaned and buffed" means all you have is relatively shiny millscale, which eats up deoxidizers in the filler rod, and those same deoxidizers are what promote wettinging; but they were used up taking care of the shiny millscale. Clean, clean, clean, clean, clean, clean, clean, clean, clean, clean, clean. :) If it pops and you see porosity you likely lost shielding gas coverage which can be due to a multitude of reasons, but most likely a combination of too long arc length, too much torch angle, too much stickout. The orange dust of death means you most definitely dipped the tungsten. When this happens I would suggest to stop and use a new sharpened tungsten or sharpen the one you just dipped. Oh and Clean, clean, clean, clean, clean, clean, clean, clean, clean, clean, clean. :)

Re: Need some TIG technique advice

Posted: Mon Sep 28, 2020 7:02 am
by cj737
Oscar wrote:
By definition, per second (1/s) is the unit of Hertz. The time unit of PPS is equivalent to Hz, because it's 'per second'.
I know what Hz is. It is not used in reference to pulse, but to AC waveforms in welding. Pull your head out-

Re: Need some TIG technique advice

Posted: Mon Sep 28, 2020 8:35 am
by G-ManBart
cj737 wrote: I know what Hz is. It is not used in reference to pulse, but to AC waveforms in welding. Pull your head out-
My Everlast specs pulse from .1 to 500hz. My Miller specs pulse from .25 to 10hz. The Lincoln Precision TIG 275 my buddy has specs pulse from .1 to 20hz.

All of them have Hz listed clearly on the panel for the PPS setting, so saying Hz isn't a reference to pulse is a bit of a stretch. Sure, lots of people talk about pulse per second rather than Hz, but that doesn't mean it's the only correct reference.

Edit to add: His profile shows an AHP Alpha TIG which also uses Hz for the PPS setting.

Re: Need some TIG technique advice

Posted: Mon Sep 28, 2020 9:18 am
by Oscar
cj737 wrote:
Oscar wrote:
By definition, per second (1/s) is the unit of Hertz. The time unit of PPS is equivalent to Hz, because it's 'per second'.
I know what Hz is. It is not used in reference to pulse, but to AC waveforms in welding. Pull your head out-
Excuse me? As Gman Bart has shown, it most definitely can be used to describe PPS, because of the "PS" at the end. If a unit has "per second" at the very end of it, such as in this case, Hz can be used to describe it. Of course not all welding machines label it as such as some just use PPS, but some do use it as the unit for pulsing.

Re: Need some TIG technique advice

Posted: Mon Sep 28, 2020 1:21 pm
by BugHunter
A much more nuanced tip I didn't see mentioned, you're ending your arc rather abruptly. Taper off with the pedal and move the arc toward the already welded area as you taper off to avoid those divots at the ends of the weld. They are especially bad on Aluminum, but can be bad on carbon steel and probably a little less so on ss.

Re: Need some TIG technique advice

Posted: Mon Sep 28, 2020 2:18 pm
by johnnyv449
Thanks everyone. I read through everything and saw some things I might have said wrong.

CJ737
Filler is 3/32 not 3/16, my bad. I also tried 1/8 but every weld was extreme high. I didn't have 1/8 tungsten to try.
As far as the pulse. I have it set to 60hz for the repetition of the pulse at 50% reduction between pulses.
Welder is AHP AlphaTIG 201xd ... https://ahpwelds.com/product/ahp-alphatig-201xd

Oscar
Thanks I guess I need to seriously clean it better. I didn't know what that orange was and I'm sure I dipped the tungsten at some point. I'm doing it less but still happening especially when the tungsten is in farther. I'm trying to keep it close to have a good arc but can't see. So then I move my hand or change the angle and boom its in the weld.

You mentioned that the tungsten might be out too much. I know you can use it al little farther out if with a gas lens (or so I have been reading). How far out should that tungsten be and what size cup for an open weld such as these?

BugHunter

I do taper off at the end but definitely don't move back toward the weld. Can assume that is why many of my weld ends have either a crater or a bump on the end?

From what I understand the aluminum weld looks better and is a better weld, not that I know what I'm doing yet.
Why cant I seem to get that stack with the carbon steel? Speed? Heat? filler amount?

Just to sum up questions:

-How far out should that tungsten be and what size cup for an open weld such as these?
-I taper off the pedal at the end but don't move back toward the weld. Is why many of my weld ends have either a crater or a bump on the end?
-Why cant I seem to get that stack with the carbon steel? Speed? Heat? filler amount?
-What angle should the torch be in relation to the weld? Filler angle?
-Does it matter if I come in with the filler from the side a bit or does the filler have to be straight on?
-If it looks like the ark is blowing away to the right, is that too much argon flow? what's a good flow rate?

I know there are a number of questions but I'm just trying to make the time at the table productive. I'm going outside right now to try out these suggestions. Thanks everyone for helping me on this!

Re: Need some TIG technique advice

Posted: Mon Sep 28, 2020 7:03 pm
by sbaker56
Looks like a classic case of tig over mill scale to me, as mentioned a wire wheel simply really won't take scale off, you need to grind down to bright shiny metal with a hard disc or flapper to get it all off. It's not unreasonable to think it might have a light coating of oil on it as well depending on where you got it, after grinding I would suggest wiping it off with some acetone just to see if it makes a difference.

Re: Need some TIG technique advice

Posted: Mon Sep 28, 2020 8:07 pm
by Oscar
johnnyv449 wrote:You mentioned that the tungsten might be out too much. I know you can use it al little farther out if with a gas lens (or so I have been reading). How far out should that tungsten be and what size cup for an open weld such as these?
Everyone has their own preference. I like to keep the stick-out no more than what is needed. Meaning, I need to be able to get my preferred arc length, torch angle, and also have enough space to introduce the filler rod. So as you can see, you need to have welded for more than just a few minutes to see how all that plays a part for you. To compound the interest on that loan, those variables change when the joint geometry changes. Even just welding up coped pipes/tubes introduces constantly changing joint geometries, where by 1 second ago it was a flat weld, and now you're going uphill inside corner, etc. One general rule of thumb for a regular cup is 1-cup-diameter as a maximum (not requirement) for tungsten stick-out. The size of the cup depends on how much argon coverage you need but also accessibility.

Re: Need some TIG technique advice

Posted: Mon Sep 28, 2020 9:41 pm
by johnnyv449
Thanks everyone,

So i tried to put what you all said to work.
Cleaned with a grinding wheel then wiped with acetone
clean
clean
20200928_151715.jpg (42.73 KiB) Viewed 2004 times
This is how I prep tungsten. Wheel is only used for tungsten. I spin the tungsten in a small dremmel to cut it down the length of the tungsten. The follow up by hand for a few quick times to straighten the grinds down the length of the rod.
wheel
wheel
20200928_151612.jpg (28.43 KiB) Viewed 2004 times
tung
tung
20200928_151723.jpg (49.77 KiB) Viewed 2004 times
I have it set to about a 1/4 inch out of the cup
tungs length
tungs length
20200928_152540.jpg (41.15 KiB) Viewed 2004 times
Here is where I was at then end of this evening. Not sure what is going on with the bump at the end though.
weld today.jpg
weld today.jpg (23.51 KiB) Viewed 2004 times
I know its all about practice and learning but just want to make sure im going in the right direction!

Re: Need some TIG technique advice

Posted: Mon Sep 28, 2020 9:56 pm
by Oscar
Try to get larger pieces. It looks like you have the rhythm going, but you might need to go faster, which means more amperage. Remember that each weld attempt is a discrete event, each with it's own complete set of variables. If you take the time to write them down, and post them, you will also get a better feel for things, and it can help diagnose things that might be wrong. To me, the weld looks thoroughly cooked due to the dull gray scaled look of the bead, but I don't know if your amperage was too low, your torch height was wrong, your torch angle was wrong, your gas flow was wrong, etc, etc, etc. Want to get better fast? Describe each and every weld attempt completely, and accurately. Reason being: we can't actually see you weld.

Re: Need some TIG technique advice

Posted: Tue Sep 29, 2020 5:30 pm
by G-ManBart
I'm not an expert, but I'd say your piece still needs to be cleaned better. Grinding wheels can leave grit and other junk. I use a grinding wheel to get the mill scale mostly gone, then a flap disc to get the metal smooth and shiny. If I'm welding something important I follow the flap disc with a unitized wheel which is a non-woven abrasive sort of like scotchbrite that really gets the metal shiny. Follow that with acetone and you can pretty much rule out contamination. At the very least get the steel until it's pretty shiny and smooth.

Re: Need some TIG technique advice

Posted: Tue Sep 29, 2020 8:14 pm
by Poland308
For basic steel tig practice. I’d recommend a 6in x 6in x 3/8 plate. Ground clean. Pad some 5 inch beads with 130 amps and 3/32 70s2.

Re: Need some TIG technique advice

Posted: Fri Oct 02, 2020 12:28 pm
by johnnyv449
Thanks everyone again for all the help. I did what Oscar said and looked at each weld. New table top and scrap material coming today so it should be much better.
Cleaning - grind, wheel then acetone
clean.jpg
clean.jpg (39.26 KiB) Viewed 1772 times
Weld 1
Material 1/8"
filler 1/8 ER70S-6 Filler
2% Thoriated (red) 30 degree angle point
Argon 20 CFH
#6 Cup
130 Amps
1.jpg
1.jpg (21.1 KiB) Viewed 1770 times
Weld 2
Material 3/16"
filler 3/32 ER70S-6 Filler
2% Thoriated (red) 15 degree angle point
Argon 20 CFH
#7 Cup
130 Amps
3.jpg
3.jpg (20.53 KiB) Viewed 1770 times
Weld 3 - tried to sort of loop the torch as if it was swirling
Material 3/16"
filler 3/32 ER70S-6 Filler
2% Thoriated (red) 15 degree angle point
Argon 20 CFH
#7 cup
130 Amps
4.jpg
4.jpg (47.59 KiB) Viewed 1770 times
Inside Angle - 2 passes on each
Material 1/8"
filler 3/32 then 1/8 ER70S-6 Filler
2% Thoriated (red) 15 degree angle point
Argon 21 CFH
#6 cup
130 Amps
angle.jpg
angle.jpg (36.98 KiB) Viewed 1772 times
Should the plate welds be higher? All flat welds sem to be very flat and less defined. Torch is held between about 15 degree angle. If I speed up the dips almost get pointy. Also what is that little slag I see in some of these?

Also if I get a new TIG torch with a little more flex in the head, still a 17, are they generally compatible?
Suggestions?

Re: Need some TIG technique advice

Posted: Fri Oct 02, 2020 3:04 pm
by cj737
Your CFH only need be 2x cup size.

The “sag” gravity. Add the filler to the top edge of the puddle on a vertical.

Start with 130 amps, but taper down as the heat accumulates (this is the hard part to teach as takes lots of practice to “see” it happening).

Are you using a gas lens? If not, add that to your aresenal.

Re: Need some TIG technique advice

Posted: Fri Oct 02, 2020 7:26 pm
by Poland308
The issues your having are due to overheating the base metal. Your coupons are too thin and to small.

Re: Need some TIG technique advice

Posted: Mon Oct 05, 2020 8:18 pm
by johnnyv449
so i got a new top for the table so nice and flat. I also got 2 large peieces of 3/8 plate to practice on so that I dont overheat everything. The welds are getting much better but I have 2 questions.

All of the welds are stacking better but not wide. I have done a few wider ones and that seems to be how i move the torch to the side as it progresses forward. What causes a weld to be wider?

Also I have a bunch of gas lenses I've been trying different ones, different cups and lower flow rates on the argon. Everything seems very in control as far as arc and motion as long as I am using a regular setup. #6 seems the best for me at this time. As soon as I change over to a gas lens everything goes nuts. Arc is not consistent, and it turns to a mess. I've lowered the argon but no idea what is going on with the gas lens.

Thoughts?

Re: Need some TIG technique advice

Posted: Mon Oct 05, 2020 9:23 pm
by BugHunter
Poland308 wrote:The issues your having are due to overheating the base metal. Your coupons are too thin and to small.
^^^^
Yep, you're cooking the part. Either clamp your material to a large steel table to use as a heat sink, or go to larger pieces. Or turn your amps down about a mile.

Re: Need some TIG technique advice

Posted: Tue Oct 06, 2020 12:36 pm
by johnnyv449
Thanks. The table that I made last week was 3x3x/8 steel top. I'm still working on getting all of the steel mill scale off to get the table shiney for better conductivity. The peieces im welding on are 12x12x3/8 steel plate. I would guess im cooking it being im doing a few welds at a time butI am moving to different corners on each. Im at 130 amps so I guess ill drop down and slow the torch as well to let it wet out.

Im just trying to figure out the time/speed to let the weld widen but not melt every dip together. That's experience I know.

Any idea why everything goes nuts with the gas lens?

Re: Need some TIG technique advice

Posted: Tue Oct 06, 2020 8:21 pm
by BillE.Dee
what is the distance between the tungsten and the base metal ? True there is one weld that got dipped by accident ... and ... the rest are seeming overheated.
Just try running beads without filler and see how you make out. Get close, but no whoopsies. Maybe not so much angle on the dangle, ya just need a peek at the tungsten. the cups are in 16ths opening.., #5 = 5/16, don't exceed that number with stickout. But, you'll need twice that first number for gas flow.

Buggy, what was that tangent thing you told me about?? I think that explanation will help here.

Don't get upset Johnny,,,take a skip around the building and gather your thoughts. I learn every day and I'm over 70. Not near as nervous as I used to be, BUT ,,, jerky is a whole nuther story.
gramps

Re: Need some TIG technique advice

Posted: Tue Oct 06, 2020 8:47 pm
by Oscar
Theyre not too bad for starting out, but what is your actual stick out and actual arc length? Without guessing.

Re: Need some TIG technique advice

Posted: Tue Oct 06, 2020 10:36 pm
by BugHunter
BillE.Dee wrote: Buggy, what was that tangent thing you told me about?? I think that explanation will help here.
Bill, was I sober? :lol:

I need more context, :lol: I can't remember what I did today...

Re: Need some TIG technique advice

Posted: Wed Oct 07, 2020 7:57 am
by BillE.Dee
Buggy, you're awesome. I believe the first I was out you explained the arc being affected by distance and tilt of the torch for "perfection".

Re: Need some TIG technique advice

Posted: Wed Oct 07, 2020 1:15 pm
by BugHunter
BillE.Dee wrote:Buggy, you're awesome. I believe the first I was out you explained the arc being affected by distance and tilt of the torch for "perfection".
Oh, yea now I remember. I said about how as you tilt the torch away from the part, the relationship of energy produced vs what ends up in the part is roughly a relationship like the tangent of the angle. Meaning as you tilt sideways, you quickly lose the energy and at a certain point, there's virtually no energy going in the part. To be more precise, the tangent function more describes the amount of energy reflected off, not what goes in, but you get the idea. It's a non-linear relationship which quickly goes south as you tilt the torch. Not any big revelation to anyone who's run a tig torch, but not many folks really think about the losses and try to quantify it like that.