Welding Tips and Tricks

I'm new to tig welding and need help, I've ran around the last two days trying to find the problem and have done everything i could possibly think of tho fix getting porosity. I can run a a couple good 4 inch beads then all of a sudden the porosity starts. I'm not adding filler wire just running the torch on some 2"x3/16" flat strap i just bought to practice on. I clean the mill scale off the metal with a new flap disc till the metal is shiny. I've tried running from 90-140 amps (off a lincoln Ranger 305G scratch start). My torch is a radnor 17FV 3/32 tungsten and I am running DCEN with 100% argon. I have tried pressures of gas of 8 all the way to 20 CFM. I have tried different pieces of metal and pipe. Broke off and sharpened tungsten back. I know im not dipping my tungsten. The tungsten still even looks clean and pointed after i kill the arc. I have a good ground. Anyone have any ideas??

It would not be unusual for you to accidentally close that gas valve as a new weldor as you travel along. I have switched from manual valved torches to a solenoid setup for consistency. I get it, the Ranger doesn't have that feature.

You don't indicate what size cup you're using, so CFH of gas is difficult to determine. It could also be some random breeze blowing your shielding gas away. Check for fans, windows/doors, even the welding machine itself blowing you out.

Check for leaks. If no leaks bump your argon up to 40 or so CFH to see if your reg is faulty and actually indicating way higher than what it is. This is not uncommon.

I have seen once before in some very wide and thick flat bar that some mill scale got somehow rolled under the metal, resulting in a vein of millscale running down the length of the bar. No idea how that could happen, but it drove me nuts trying to figure out why I kept getting porosity and fireworks. Finally realized that there was a pattern to where it would happen in the stock, so cut it open and sure enough. The chances of that are low, but may be worth checking that as a last resort.

All good advice so far...good stuff to check.

The general rule for gas flow is to take the cup size and double it...so a #8 you'd use something in the 15-20CFH range. Flow meters can be wrong, so it won't hurt to go well above and below that. As mentioned, it could be something as simple as a breeze blowing in just the right (wrong) spot.

Also, it may not be likely, but make sure the torch is assembled correctly. If the collet is in backwards it will secure the tungsten, and let some gas by, but not really enough. It could be where just enough is getting by at the start, but as the work heats up it isn't enough, or the torch heats up a touch and something expands a tiny bit to cut off even more flow.

Since you've tried more than one piece of metal that probably isn't the issue, and it sounds like you're getting it clean enough....if not you'd get porosity from the start. Thats the same with the gas...if it was contaminated you'd be getting porosity right away in every situation I can think of. I have seen bad gas that would work fine on steel, but was awful on aluminum with black soot all over the beads....swapped bottles and the problem disappeared.

If all else fails, try changing your tungsten, preferably to another type and brand.

I've had your problem twice, the second time I had some Linde 2% that confirmed it was a tungsten problem.

TIG is so sensitive to gas disturbance, double check that there are no fans on anywhere or breezes.
One other thing to consider is how hot the metal you're welding on is getting. If the base metal starts getting really hot, it can stay hot enough to introduce impurities too long and you end up losing gas coverage while the metal is red hot causing porosity or other contamination. Torch angle and travel speed affect this too. Also, if you're stacking beads, contaminants from the previous bead can build up in your subsequent passes.
Really double check that your torch is setup properly and that gas flow is not being impeded. There are so many ways (ive done them) to screw this up by incorrect assembly, over-tightening, bad regulator... If you have a manual valve you should be able to open it and listen closely to hear the gas flowing- not a guarantee but useful.

[quote="tyautry"]I'm new to tig welding and need help, I've ran around the last two days trying to find the problem and have done everything i could possibly think of tho fix getting porosity.

Most of time you will weld in your life only 3 things , ''BLACK METAL'' , SS and Alu ... no thatmeny ppl know ss and alu is much more easy to weld as Black .. You have maybe all stuff good just you need to rememeber black metal dont like overheating. Is to much different when you welding Flat bar - Hot rolled ( black oil-carbon on top ) and cold pulled material with sharp edges and clen top .. . Big problem is carbon , humidity , oil inside ... when you just melting - that we not calling welding ... welding is proces when you heating and adding material . People calling even wrong way force welding that is just force melting and on the end is melted joint .. But back to your problem.... When you stay for long time and you not adding matrial then whole marerial structure colapsed because you are heating over 2500C and you breaking carbon and FE particualte frame .. we are not going to much deep ... easy way to explain on SS you will burn CHROME what is making SS rezisten and is black quazee calling oxyadation then on black material you will have porosity and is nothing to do with CUP size or GAS flow part of if you are not using CUP size 4 and electrode size 2.4 and flowing only 4-6L/min. If you following all basic rusel as is keep close us much as possible and tip is not sticking more then 8-10mm ( standard 2 -6 mm ) using gas flow abut 8 - 12L/min the you can have even hole in your house and you will not get porosity . If you dont know how to grind your electrode just have look below that will help you for sure and just do not listen ppl about angle on tip , importent is size and that you need to mach with amperage and material always keep tip sharp as on my video because oposit site ( arc - flame ) will be big as is your tip and you dont want to heat pleace around you want to heat exact poin for welding . Sorry for gramatic just finish 14h job , so time for 2nd beer and bed time .. If you cant help then try to make some pic or video and we will try to help you ..

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