Need advice. What went wrong?

[Tireman9]

Background: Been welding stainless exhaust system for hot rod. No problems other than my inability to hold the tip real close (combination of hand tremmor and eye sight problems) to get a nice small bead. Finished 15 butt joints with this quality.


Was getting low on gas (less than 300 psi showing) but wanted to finish one more joint when it all went to hell.


Sparks, spatter tip eroding etc. Ground out bad weld, I changed tingstin got same, ground out bad weld and changed gas bottle. More of the same, Even tried to do edge of weld bench but still got lots of sparks, spatter etc like this.


Here are tips before and after


What's the problem and How do I fix it?

[MAStuart]

Looks like no gas flow. But I am no expert. I struggle with my welding. Make shure you have gas flowing.

[Chris Bspoke]

looks like a few things , first lack of gas coverage , possible contamination of your ceramic shroud , bad earth connection , incorrect grinding of tungsten looks like the grinding marks go round the dia not down its length plus far to course a grinding , they should be real smooth

[MAStuart]

Chris, What gets contaminated on a ceramic cup? Do you have a picture of a contaminate one? How does it end up affecting the weld? Thanks

[Tireman9]

Thanks
With your suggestions I went back and checked all gas settings & connections. It looks like two things happened. My big tank went empty even though it was reading 200 - 300 psi. Then when I moved the regulator to my back-up small tank I aparently managed to shut the flow meter off so was getting no Argon.
Just ran test bead and it my normal so-so job.
Thanks again for pointing me in right direction.

re Tungsten
While this didn't contribute to the problem I did go back and revise my grinding method.

[Chris Bspoke]

your tungsten prep looks better but you want to use a finer abrasive as all the course sanding marks let the arc wander around , plus for steel you want the point to be as sharp as possible.This in turn will help you to control the puddle better and get better welds.

Mastuart sorry haven't got any pics of dirty ceramic cups as they tend to end up straight in the bin . But if you look close inside one that you have been using for a while under a lens you will see lots of little metal balls stuck to the sides ,every time you touch down or stab the tungsten with filler rod you get a few more stick to the inside . These heat up when your are welding and contaminate your shield gas and thus your weld , it causes more of a problem with ally . It's all about keeping your weldment clean but with tig welding people forget the ceramic cups ( it aint broke so it's good to use ) they are a consumable which means they get used . I do a fair bit of bench welding in my job 25% of it is ally , have a nice fancy tig plant that remembers 30 setups for repeat jobs , will do a job perfect welds 2 weeks latter come to repeat job and welds will look like bird droppings 9 times out of ten the problem is the ceramic cup as someone has filled it with crap ( usually me as i'm the only person who use's said plant ).Hope this helps if not ask and i'll try to answer

Cheers Chris Cant

[jlrussell4]

Hi Chris,

Thanks for the advice on the cups. I think I'll be looking for some new ones soon.

[MAStuart]

Chris,
Thanks for the tip! Looking at the picture below, I assume I belong to the "if it ain't broke, it's the good to go club". In the picture, the second cup from the right was the cup I was just using to weld the panel on my coupe (aluminum). I contaminated my tungston several times. You can see at least one little ball of aluminum in that cup. The other cups it is hard to tell how many times the tungston was contaminated. I assume the ones towards the left have the most contamination. In the past I have seen where I struck the arc and it arced over towards the cup. Thanks again for the tip.

DSCN3621.JPG

[metal manny]

Re gas flow - always check that the torch welding cable is not pinched under something heavy, restricting gas flow.

You can use a belt linisher with an ultra-fine grit to put the finish on the tungsten. Run the electrode in line with belt and not perpendicular to its travel. The dust from some tungstens is considered a radioactive danger so don't breathe it in.

Manny

[Chris Bspoke]

You got it Stuart as you said you have seen your arc wander of on strick up , it carrys on wandering around when you are welding , gives you a poor weld and leaves you feeling deflated cause you know you can weld better . And yes I'd bin the three ceramics on the left of your pic they all look pretty bad . I know they cost money but if we all want to weld to the best of our abilities we have to keep our kit in good condition , we wouldn't use a planishing hammer that had a face that looked like a golf ball so why use damaged welding kit . Hope this helps out those that read it with some of their welding problems.

Cheers Chris Cant