Tig welding project

[usmcruz]

It's stainless... You need to back purge it, or use the paste. That's oxidation.

Thanks allot buddy, thats the information I needed to hear. So should I grind it all back and re-weld it. How do I treat the stainless steel now seeing that I have oxidation. Will it rust now, Pleas help!

[Laiky]

If you put some corks or plugs in the bung holes() then you can just fill it with argon and it will work ok. I usually fill it until a lighter will go out if held near the top fill hole. The splitter will work fine too, but you might need a restriction in back purge line so the torch gets enough gas. I find a small ball valve works just fine, you can throttle it that way. Fill it fast then choke it down to give the torch more flow. You could also get 2 flowmeters from HTP weld off of e-bay for 90 bucks and a western T fitting for 20 bucks more. Then you will be all set for next time.

[usmcruz]

Thank you for the advice. Im gonna do that next time. Did I royally screw up these welds though If I grind the golf ***** back?

[Fishy Jim]

Stainless rusts really good when it gets hot enough. That's exactly why you need to back purge it.

Grinding the scale and crystals off down to base metal is all you need to do. With any luck, it'll just be a light surface issue.

If it were me, I'd get some dry ice. Toss it in there and start welding. No need to worry about plugging holes, as the dry ice will continue to sublimate the whole time. It's cheap, and readily available. Save your gas for the hot end of the process.

[c wagner]

If it were me, I'd get some dry ice. Toss it in there and start welding. No need to worry about plugging holes, as the dry ice will continue to sublimate the whole time. It's cheap, and readily available. Save your gas for the hot end of the process.

That works?
Today wasn't wasted after all!!!

[Fishy Jim]

If you have really big holes, or ones on the bottom, I'd cover them with some tape. Otherwise, they sell dry ice in pellet form for medical use (transporting specimens, etc). I got mine from work when I was using it last, but we didn't spend much and most of that was on the delivery. If you wanted a little cooler full, I bet they wouldn't charge ya.

With what argon fills cost these days, I'd use that before I pissed away good shielding gas for a back-purge.

[man of steel]

the condition you see inside your tank is called sugaring and it is a tell tale sign that you didnt purge while welding your root in.it is a weakened joint because of the atmospheric contamination that causes it.wire wheel brush it and grind then repass without filler to burn out any impurities then after cooling try with filler and dont crank the amps too high .but move quickly,let me know how it works out for you. i have lots of pictures of my ss projects if it will help.

[usmcruz]

the condition you see inside your tank is called sugaring and it is a tell tale sign that you didnt purge while welding your root in.it is a weakened joint because of the atmospheric contamination that causes it.wire wheel brush it and grind then repass without filler to burn out any impurities then after cooling try with filler and dont crank the amps too high .but move quickly,let me know how it works out for you. i have lots of pictures of my ss projects if it will help.

I wonder after reading your post that the solar flux even worked. Meaning the fittings, and back side of the welds I pasted with solar flux had allot of sugaring as well. Thank you for post, it has helped me understand what is going on with my tig welding. If you got pictures of your projects, I would really like to see them to get a better understanding of whats going on, if its not too much trouble.

One thing that I think is also the problems, is that, and tell me if Im wrong, but I went on the miller website, and used there tig calculator because I felt that all the tig welds were burning too hot even with the amps turned down to 65 amps.

Come to find out the tig calculator states to use a 1/16 inch diameter tungsten, and this whole time Ive been using a 3/32 inch diameter tungsten. Would this make a differnence and the cause of my burn throughs?

I bit the bullet today and with the advice of some bought a Y connector shutoff, and another length of gas hose to back purge.

Question, how do you guys postion the hose to back purge, or have you fashions some kind of device that clamps onto the back of the weld area with magnets to purch a specific spot?

Im confused, should I just position the argon hose to just let the argon flow against the back wall, or rig something up?

Would securing some purge device with magnets disrupt the tig current?

Sorry for all the questions, the school I went too didnt cover this.

That is real interesting with dry ice. How close would the ice have to be, or can I throw a block of it into the keg Im welding?

[Fishy Jim]

The dry ice sublimates rather rapidly at room temp (the boiling point is -107F), and it turns directly into CO2 gas. You wouldn't want the dry ice next to the weld because of the temp differential, but it'll boil off pretty quick once the temp rises and it will produce a lot of volume, and can build quite a bit of pressure, so you don't want it sealed up!

We used to take surplus dry ice and put it in 20oz pop bottles. Nice little "pop" that resembles a shotgun report.

With the argon back purge, basically, you do the same thing. Seal off the holes so you can fill the keg with gas. Once the air is all displaced, you weld.

[usmcruz]

Thanks fellas, I love this forum, lots of information out there. I just so happen to have SS Flat bar and tubing in the garage, so Im gonna rig it up. Thanks again.


Could the 3/32 tungsten be the cause of the spot burning too hot, and would going down to the 1/16 tungsten like the miller tig calculator says make a big difference?, if so I gotta order some now, because I got a SS project coming up.