Learn me on TIG purge setups.

[Byro]

So got the TIG setup for my ESAB 235, played around with some stainless making air box eliminators for the ATC250Rs. No purge so the inside sugars like crazy and flap drumming them is a PITA. No idea what I need for a purge setup.

 

[CarterKraft]

A hose with ball valve, flow meter and tin foil worked for me.

They have sweet silicone plugs and stuff now that I would be tempted to buy if I had a consistent project scope.

 

[Provience]

aluminum tape is also easy to work with, shape and mold to whatever you want.

the only actual reusable purge thing i've ever made was a rectangle, about 1"x3" out of stainless, then shoved a bunch of steel wool in there, then put a stainless plate with bunch of holes as a cover. it has a tube that goes into the bottom.

I use it for back purging some thing which is multi-layered so that the layer repair guys can just cut out a simple shape.

something like that, tape off the end, dangle a hose in there, have at it. Argon is heavier than air, so put your tube flowing from the valve at the top and tape it up well. It doesn't really take much flow into the back if you have a good seal on the bottom

 

[tracyb]

i run a dual reg off the bottle. a cheap one off amazon. and always have a roll of aluminum foil around to plug holes/ seal ends etc.

you can also use solar flux. better for exhaust systems, just got the make sure its all cleaned out if used on the intake side.



just in welding small stainless parts in general, i also use citric acid to help clean the weld haz, (a big pot full heated on a crab cooker and drop the parts in for a few hours) sometimes use pickling paste. passivates the ss and helps get rid of any sugaring if. i've messed around with the citric acid and an electrical charge and have been meaning to come up with an electro plating/ cleaning dedicated space, but gotta catch up on work first.

 

[Byro]

Never thought of pickling. My old lady does silver smithing and does the same deal with her silver pieces to take off the heat/solder marks.

Any recommendations for a not shitty dual flow reg?

And flow rate for the purge? Match the torch flow or less I would assume since it’s not directly in “atmosphere”?

 

[tracyb]

stainless pickling paste is some nasty stuff. iirc, the main chemical targets the calsium in your bones if you make skin contact. but i could be wrong. citric acid is so safe bare hands are no problem, and its very effective with heat or elec current. you can get the pickling stuff a weld supply, i wanna say the last quart jar i bought was around $150. i really only use the pickle for sanitary jobs, water supply and food mfg stuff.

i think ospho also works to help passivate ss, but look it up before trying. commercial boat guys around here use a shit ton of ospho and aluma bright on everything.



this is the regulator that i use. works as it should, no complaints. it does need to be adjusted as the bottle loses pressure, i'm always adjusting it depending on the task nbd for me.

https://www.amazon.com/gp/product/B07XNYNT2Z/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

a y splitter off your existing reg is probably fine for most stuff. when i did that i ran the flow rate a bit high, had a ball valve on the purge hose and used a gas valve torch to dial down the flow at the weld. used the flow rate meter linked below to set it, then left alone as the tig has a gas selenoid.
flow rate completely depends on job and how well its sealed up. 5-40cfm maybe?



i also dont trust any reglator to tell me what the flow is at the torch, i highly recommend every welder have one. especially for tig, using a gas lens flow rate can be really low.

https://www.amazon.com/Professional-Tester-Flowmeter-peashooter-Welding/dp/B06XW8H8W1/ref=sr_1_9?crid=1Y6ODFCD84JQR&keywords=gas+flow+meter&qid=1647112682&s=hi&sprefix=gas+flow+mete%2Ctools%2C150&sr=1-9

i know its really dumb and probably doesn't need to be said. but i've seen allot of welders that should know better using cheap steel wire wheels on stainless. make sure to use stainless wheels on stainless. for sanitary stuff i keep seperate stainless only consumables and gloves and such in a big ziploc bag. clean clean clean

 

[Byro]

Solid info, thanks. I use ospho all the time on mild steel, cages, bumpers, etc keeps everything from flash rusting before the customer paints/powder coats. I’ll have to do a little test piece next time I do some air box eliminators and see what it does.

 

[Brad]

stainless pickling paste is some nasty stuff. iirc, the main chemical targets the calsium in your bones if you make skin contact. but i could be wrong. citric acid is so safe bare hands are no problem, and its very effective with heat or elec current. you can get the pickling stuff a weld supply, i wanna say the last quart jar i bought was around $150. i really only use the pickle for sanitary jobs, water supply and food mfg stuff.

i think ospho also works to help passivate ss, but look it up before trying. commercial boat guys around here use a shit ton of ospho and aluma bright on everything.



this is the regulator that i use. works as it should, no complaints. it does need to be adjusted as the bottle loses pressure, i'm always adjusting it depending on the task nbd for me.

https://www.amazon.com/gp/product/B07XNYNT2Z/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

a y splitter off your existing reg is probably fine for most stuff. when i did that i ran the flow rate a bit high, had a ball valve on the purge hose and used a gas valve torch to dial down the flow at the weld. used the flow rate meter linked below to set it, then left alone as the tig has a gas selenoid.
flow rate completely depends on job and how well its sealed up. 5-40cfm maybe?



i also dont trust any reglator to tell me what the flow is at the torch, i highly recommend every welder have one. especially for tig, using a gas lens flow rate can be really low.

https://www.amazon.com/Professional-Tester-Flowmeter-peashooter-Welding/dp/B06XW8H8W1/ref=sr_1_9?crid=1Y6ODFCD84JQR&keywords=gas+flow+meter&qid=1647112682&s=hi&sprefix=gas+flow+mete%2Ctools%2C150&sr=1-9

i know its really dumb and probably doesn't need to be said. but i've seen allot of welders that should know better using cheap steel wire wheels on stainless. make sure to use stainless wheels on stainless. for sanitary stuff i keep seperate stainless only consumables and gloves and such in a big ziploc bag. clean clean clean

The stainless wire wheels are key when working with anything besides steel. When I worked at a pressure vessel shop we had a stainless tower that had all sorts of rusty spots where guys were cross contaminating wire wheels and abrasives. Rust marks all over after hydro testing. Had to end up paying contractors to clean it all since it had already shipped to the refinery. I’ve always painted stainless abrasives blue, steel red and aluminum yellow

 

[Bggrnchvy]

We use N2 to purge, way cheaper than Ar and since it's on the backside does not need the resistance to arc heat. Make sense when you have multiple guys chewing through gas every day.

Like said, aluminum tape make sense most of the time. Most of the guys have the silicone stopper kits though for process tube, easy to pop in and no glue residue to clean up.

It might go without saying, but you need to actually purge out all the O2 in the vessel being welded, not just turn the purge on and go to town.

Purge pressure can cause autogenous welds to bulge out, if they don't blow out, so you have to keep it low. Purge flow rate varies widely depending on what you're welding and how much internal volume. The volume also dictates how long you should purge prior to welding. 4-6 times the internal volume in purge gas is normal prior to striking the arc. I think 6x is ASME BPE code required.

 

[tracyb]

The stainless wire wheels are key when working with anything besides steel. When I worked at a pressure vessel shop we had a stainless tower that had all sorts of rusty spots where guys were cross contaminating wire wheels and abrasives. Rust marks all over after hydro testing. Had to end up paying contractors to clean it all since it had already shipped to the refinery. I’ve always painted stainless abrasives blue, steel red and aluminum yellow

i had a stainless tank i was building for a small water dept. the helper i had was a good welder, but other than that a bit retarded. he used a steel wire wheel on about 10' of seam, i wanted kill him, i took allot of time to make the tank as nice as possible and that bit of seam stuck out like a sore thumb.

painting consumables/ abrasives is a damn good idea. thats exactly what i did after the incident. and made dedicated alumium/ ss storage area in a cabinet to keep it all as clean as possibble.

 

[Brad]

i had a stainless tank i was building for a small water dept. the helper i had was a good welder, but other than that a bit retarded. he used a steel wire wheel on about 10' of seam, i wanted kill him, i took allot of time to make the tank as nice as possible and that bit of seam stuck out like a sore thumb.

painting consumables/ abrasives is a damn good idea. thats exactly what i did after the incident. and made dedicated alumium/ ss storage area in a cabinet to keep it all as clean as possibble.

In this the aluminum ones are green because I have them matching the filler rod tubes we have for each material

 

[4Eyedturd]

Y’all ever used one of those electrically charged brushes with some kind of liquid to clean stainless welds? I’ve seen a few videos of them but never used one

 

[WaterH]

I have a small nitrogen bottle and flow gauge for HVAC work. Now I just get it filled with argon. It still works for the hvac and back purging, and in a pinch I can use it for tig when my main tank runs out.

 

[tracyb]

Y’all ever used one of those electrically charged brushes with some kind of liquid to clean stainless welds? I’ve seen a few videos of them but never used one

yeah there are allot of different setups, currently the most used is citric acid for the liquid and the special part is the tungsten conductor and cover pads. i bought the pads and conductor using a welder as the power source and it works good. but the conductuve bath i touched on above works even better and you can just walk away while it works. as a bonus you can reverse the polarity and use the citric acid bath to plate the metal, i did that first and came back to a bunch of nice stainless parts coated in copper.. oops, you wan the stainless to flow towards the conductor for passivation.

to just brush it on and be effective the expensive units work awesome, they way i set up mine i burnt threw the pads quick and it was more of a pain for big jobs... thats why i went to using the small bath or other ways, like a burnisher with a fleece/ scotch brite pad wheel, for the bigger jobs

 

[Bggrnchvy]

Y’all ever used one of those electrically charged brushes with some kind of liquid to clean stainless welds? I’ve seen a few videos of them but never used one

Walter Surfox is the one we demo'ed maybe 5 years ago. Needs a lot of rinse water and as a zero discharge facility, it was more expensive than mechanical methods. Works well though.

 

[tracyb]

Walter Surfox is the one we demo'ed maybe 5 years ago. Needs a lot of rinse water and as a zero discharge facility, it was more expensive than mechanical methods. Works well though.

i almost positive the walter surfox is a citric acid system. i'd have to check to be sure. but its their consumables i've used used for my redneck shit. a gallon of their 'special' citric acid costs 10x more than a 10lb bag of citric powder. i've still got the gallon bottle i had to buy before they would sell me consumables. i think it was $70 3-4yrs ago

its used allot in the dairy farms and seafood processing around here. discharge is washed into the puget sound, pacific ocean with no treatment.

if it is citric, as i believe it is, the 'zero discharge' is dumb, no its retarded. the whole point is that its less hazardous than the shit you flush down the toilet. if going zero discharge get some real chemicals. eat your bones stuff in there, a little goes a long ways. wipe it up with a rag and no discharge, just far more toxic to the landfill. gotta be green and all tho

 

[Bggrnchvy]

i almost positive the walter surfox is a citric acid system. i'd have to check to be sure. but its their consumables i've used used for my redneck shit. a gallon of their 'special' citric acid costs 10x more than a 10lb bag of citric powder. i've still got the gallon bottle i had to buy before they would sell me consumables. i think it was $70 3-4yrs ago

its used allot in the dairy farms and seafood processing around here. discharge is washed into the puget sound, pacific ocean with no treatment.

if it is citric, as i believe it is, the 'zero discharge' is dumb, no its retarded. the whole point is that its less hazardous than the shit you flush down the toilet. if going zero discharge get some real chemicals. eat your bones stuff in there, a little goes a long ways. wipe it up with a rag and no discharge, just far more toxic to the landfill. gotta be green and all tho

Our current facility, which is changing next month, is serviced by a sanitation system with a very lacking treatment system. The water from the tap supplied by a different organization actually doesn't meet the standards for conductivity needed to go down the drain. With the BOD/COD loading of our waste stream from the residual wine, combined with the medium to high strength streams coming from the cation/anion column regeneration we just will never meet the requirements here and as such, nothing can go into the drain. It is all hold and haul @ $.25/gal.

Our new facility does allow a mixture of waste streams between hold and haul and drain if we install mag/ph/conductivity/meters which we will do. It is more tenable after we do that.

We build wine filters and service customers with them, I've got pallets of 50lb bags of granulated citric acid. I am well aware of how mild it is in comparison to the other stuff we use like the 35% HCl and H2O2. Nothing I can do to change being able to put the rinsate down the drain here however.

 

[[486]]

I just use co2 from the mig welder to backpurge while tig welding
the gas solenoid on the feeder is plugged into the feeder's control box with a normal 2 prong 110v plug, so just plug it into an extension cord and it's running full time
just stick the mig gun into whatever I'm welding and hold it there with the ground clamp
suppose it'd be easy enough to tape the trigger down on whatever purge setting you've got

tape, crappy welding gloves and whatever else is handy keeps it mostly inside the pipe

 

[[486]]

sometimes use pickling paste. passivates the ss and helps get rid of any sugaring if.

you're clearly a much better welder than I
I get the back side of the weld so damn hot that the 'sugaring' is huge crystalline blobs extending in by a half inch or so when welding stainless
with the backpurge they're just about 1/8" of filler blobs if that

 

[Gravy]

Just being an air intake or exhaust I wouldn't bother back purging, but it doesn't hurt.

Fitt up is key. You want the peices tight no gaps with a light bevel on the edge. Control your heat and fill, or no bevel and fuse the peices together.

 

[Byro]

Just being an air intake or exhaust I wouldn't bother back purging, but it doesn't hurt.

Fitt up is key. You want the peices tight no gaps with a light bevel on the edge. Control your heat and fill, or no bevel and fuse the peices together.

An average exhaust I wouldnt worry about, maybe something high end I’d purge. These intake pieces I worry about a piece getting sucked into the motor. I get my fit as tight as possible and basically fuse pass them, hardly any filler in them, but the little boogers on the inside bother me.

 

[4Eyedturd]

When you’re doing something that can’t be filled with inert gas what’s your method of reducing sugaring on the backside? Paste?

 

[Dethmachinefab]

When you’re doing something that can’t be filled with inert gas what’s your method of reducing sugaring on the backside? Paste?

Copper backing bar or a make a purge area with a small channel or angle clamped/taped/etc.

 

[tracyb]

if you dont have copper for a backing bar, aluminum works too, copper works better.


backing bars are also called chill bars, being that SS is a horrible conductor its easy to warp and deform when clamped to a bar the heat disperses quicker and helps control the warping. for ex, when welding SS countertop seams you use 3 bars one for the back and 2 on the side your welding as close to the seam as possible and clamp the hell out of it.

 

[gt1guy]

Solar Flux would be great for what the OP is doing.

 

[Byro]

Solar Flux would be great for what the OP is doing.

Go on…

 

[Dethmachinefab]

Solar Flux would be great for what the OP is doing.

Not great for a butt joint like that, you'll get it mixed into the weld puddle. Shielding the backside of something that's not open to the weld puddle like a bracket to a tank side sure.

 

[gt1guy]

As long as your fit up is good with no gaps and you can actually reach in there to apply the solar flux after you tack it together, you'll be fine.

That's what it's made for.


What you don't want to do, is paint both halves with it and then put them together/tack/weld. It will end up way too thin where you need it the thickest.

 

[gt1guy]

Just to follow up on the Solar Flux.

Been doing some practice on ss tube before I attack my header build. Cutting 1" coupons of tube and welding them together. Using Solar Flux on the joint after tacking the two pieces together.

So far I have had zero sugaring.

It melts into a slag (like stick welding) on the backside of the weld.

What it leaves when I do my part is a nice small convex weld bead on the inside.

The slag is a bit tough to knock free. Don't really have a good way to give it a wack.

This is on 321 stainless, 1.875" x 16ga tube using 347 .045 filler.

 

[[486]]

maybe one of them die grinder cup brushes with the real mean twisted-knot strands?

thanks for the followup, I've never tried that way, looks nice