GTAW welding - puddle fizzes

[LAN]

Try cleaning the area that you are welding with scotchbrite (no chemicals) before welding. 4130 tubing typically has a thin mill-scale on it. If you take that off you will notice a huge difference in your finished bead cosmetics and the way that it welds.

Good luck man

Brad

[paulrbrown]

Once saw the prettiest tubing at Rausch's shop, asked the guy there what they did to it, and they said it was precision ground....so, enough said, clean that coating/scale/earl/whatever away from the site, and keep the hydrocarbons [oils] off before hand. Hope this helps,Paul

[starweld]

I always drilled the vent hole inside of the tube, That way the whole cage was vented and there were no holes to go back and fill.

[Sparky C]

When tig welding pipe in the field we always purged the pipes with shielding gas so when the heated gases inside would be forced out during welding it would be shielding gas not air (oxygen and nitrogen).
Just a thought.
Spar C

[Vicegrip]

Heat a section of the tube away from the vent hole with a heat gun or torch. Almost too hot to touch is good enough. Get ready to close up the vent hole and drop a wet rag on the heated section of tub. This will make air want to go in rather than coming out of the vent hole. sometimes I skip the vent hole and stop the weld and let things cool off some. I find that can close up by ether welding the last bit fast or doing the heat and wet rag trick no vent hole drilled.

[MrRXL]

I had the same exact problem when I was using brake clean to clean oil off of new steel. I discovered when I used mineral spirits or a water soluble cleaner the problem went away. One day I was out of mineral spirits and I used brake clean and the problem came back. Brake clean gets into the steel and any welding process will cause the expanding gases to blow out the weld puddle.
Hope this helps.

Best regards,

[Laiky]

I would think mineral spirits would cause the problem, since its a petroleum product and leaves a residue. Now that you mention it, i think i had a problem with brake cleaner causing contamination too. I now use 100% isopropyl alcohol or in rare cases acetone and i have no more issues.

[projectwelder]

Definitely skip the noxious chemicals, a little emery cloth will go a long way in cleaning the tubing. As for plugging the vent holes, you have a few options... To keep the environment out, you can use a rubber plug or a pop rivet.

John

[griff01]

I would think mineral spirits would cause the problem, since its a petroleum product and leaves a residue. Now that you mention it, i think i had a problem with brake cleaner causing contamination too. I now use 100% isopropyl alcohol or in rare cases acetone and i have no more issues.

Isn't isopropyl alcohol 30% water??

Griff

[Aerometalworker]

Isn't isopropyl alcohol 30% water??

Griff

Griff,
Depends on the solution. I use either 70 or 90 percent for my cleaning, so it would be either 30 or 10 percent water. Stay away from heavy hydrocarbon cleaners, and the light ones arent good for your health. Isopropyl is just fine for 4130 and mild steel, used and accepted byt aircraft guys after years of use and testing on steel, stainless, aluminum, but NOT magnesium. Hydrocarbon cleaners have been linked to hydrogen embrittlement of 4130 when using the Tig, Mig or Arc process.
-Aaron