Tig post flow

[jnyfixit]

Beginning welder here, just starting to tig some 3/16 steel and 1/8 alum. for practice. What should the post flow be set at? I have it set at 14 and it seems like the tank is getting light quick. How long should a tank of argon last?
Thanks

[TS-Off-Road]

I have mine set at 3 seconds for steel and aluminum, works fine.

A tank of argon will last until it's empty. LOL, really, I have no idea.

[Synchroman]

Beginning welder here, just starting to tig some 3/16 steel and 1/8 alum. for practice. What should the post flow be set at? I have it set at 14 and it seems like the tank is getting light quick. How long should a tank of argon last?
Thanks

According to the manual, my SW 200 privides a minimum of 5 seconds of auto postflow for 50 amps or less. That seems to be a bit much for me. It's possoble to override that setting and adjust manually for anything from 1 to 25 seconds. Using the rule of thumb of 1 amp per .001 of thickness, you would be using about 100-125 amps for 1/8" material. With auto post flow on my machine, that would be ten seconds which would likely be wasting gas. If your machine is adjustable, I'd try 5 seconds for 1/8" material and see how it goes. That should be OK for a starting point.

As far as how long a tank of gas will last...that has to do with your gas flow setting. Assuming that you have a 160 cubic foot cylinder, if you were to use somewhere around 20 standard cubic feet per hour, your tank would be close to empty after 8 hours. (160 divided by 20 = 8)

You can do a lot of welding in 8 hours and perhaps could use less than 20 SCFH if you are doing small gauge work.

Happy Trails!

[fun4now]

simple rule of thumb is 1 sec. per 10 amps of welding power.
weld at 80 amps = 8sec.
this can be varied a bit depending on the material. and seems a lil high. i'll have to see if i can dig up where i found it as a rule of thumb. cant remember if it was my TIG book or welding mag.

the post flow can really eat up a tank of argon if you are learning thats for shore. lots of start stops with long post floe's add up fast.
i'll post back what i find.

[Steve]

There should be enough post flow so the tungsten doen't change color after welding. So it would seem to vary with the wedling current.

[Heavy D]

postflow

I've been takeing classes @ a community college and the correct answer is 1 second for every 10 amps althought I also agree this seems a little long for use with mild steel, but not for aluminum or stainless. hope this helps

[6010]

I know the preset on a syncrowave seems like a long post flow. My question is, would you need more post flow coverage at the end of the weld than you would get gas coverage say, in the middle of the weld. I am talking about the time the gas would be covering a portion of the weld as you progress. You would have to be going very slow for that to happen it seems to me with such a long post weld purge. I know you get a lot of purge time at the beginning of the weld because you are heating the metal, so is there a reason you need a lot of purge time at the end because this is a place more susceptible place for cracking ??

Also, is there a difference in importance of the gas purge related to the metal you are welding. Is it any less critical for mild steel than for aluminum that would maybe allow a lower post flow time ??

If you were not getting enough post flow how would know - would it be in the color of the weld or porosity. ??

These are just a couple of questions I have about post flow.

[fun4now]

yes you do need more post flow for some metals, SS is one and some of the exotics are also needing longer coverage. thats why they make flow trailers that extend out behind the torch to maintain coverage after you pass the area welded. in steel its not a big deal. the longer post floe's are also to keep the tungsten coverd wile it cools. thus the amp to time ratio. the hotter the tung. the longer the post flow needs to be. depending on the material you are welding you may not need to keep the torch over the work for the hole post flow but it dose still need to cover the tungsten.
not enough gas coverage will show in the weld as well as the tung.

as i understood it the syncrowave 200's post flow is automatically adjusted as the amps change but it can be put into manual mode if you need to change for specialty metals. this can really help out the beginner that doesn't know to alter the flow setting for the different amp settings. on my TA-185 if i am changing my welding amps i have to reset my post flow also or risk fouling my tungsten or waisting gas. nothing wrong with that as long as you know to and remember to change it. if you have the syncro 200 leaving it in auto mode would be the best option IMO. wish i had that option.
miller did a great job of setting up the syncro 200 for the hobby guy just starting out to learn on as well as for the pro that has it down pat. really nice unit, i'm still bummed i could not power it. i could have had a syncro200 for about what i payed for my TA-185. and for my uses the syncro would be fine. as a hobby guy i really don't need all the extras of the inverters. yes they are nice and all but really not needed for most hobby guys other than the power options.
any how there are several trailing shields available and many make there own to best suit the need for the part they need it on. making your own is pretty simple and allows you to cater it to the shape part you are working on.

[6010]

Thanks James,

I have never even seen the shields. You will have to remember that I am not a welder by trade and I only have experience with what I have seen in my career. That has been limited to pipe welding, because I saw a lot of this having worked in a paper mill, and mostly repair work on my other jobs when something broke. Oh yea, and then there was the government jobs for the managers

You are right about the settings on the syncrowave 200. With what little I know everything seems so perfect, I am scared to change anything