Judge my welds please

[skrall]

I know you get a lot of this, but your input is very much apreciated. This is the first tig welding i've done since the introductory course I did a couple of months ago.

This is 1.6mm stainless welded at around 50-60amps.
This is the top of the weld, the one on the left being the most recent and best looking, there is a slight browning around the edge, but I'm really happy with that, and confident it wasn't a fluke.

The main concern I have is that the back of the weld is all black and sooty looking. I'm not doing anything structural, but how much will this compromise the integrity of the weld? What can I do to improve this apart from back purging? was thinking if I could go for less penetration. Your opinions please.

Cheers
Steve.

 

[Shox Dr]

Far left looks good to me, (if not a little hot) the Black stuff on the back is called sugaring, and is caused by lack of shielding gas, one way to stop that is to use a backing strip (the easiest on sheet, or to shield it with gas (not easy on sheet) . Sometimes you really cannot help that on SS, but as you get better it will become less often. 50-60 amps is kind of high for 1.5, but then it all depends on speed, how sharp the tungsten is, and tungsten to work distance.


Sorry for been a bit vague, cup oftea and 5mins before a scoot off... Hotrodder will give you the definitive answer when he reads this

 

[Burf86]

http://www.weldingtipsandtricks.com/aluminum-welding-training.html

That website is awesome, so much info, aimed at beginners from experts

 

[Wozzaaah]

That website is awesome

So's this one Burf.
Plenty of good info on here, no need to look elsewhere for it.

 

[Burf86]

Yeah no doubt, but that one is good too.
The guy that runs it puts ken loads of effort into it, videos posted weekly aswell as loads of pages of info.
Spent every evening for a week checking it out

 

[Burning Elbows]

i may be wrong it happens alot ... but
i would reduce your amps a touch as it looks like your rushing your fingers , use a 1 mm filler rod so you dont knock too much heat out of your weld puddle when you dip and reduce your down sloap to 0.3s and increase your post flow to 3s to help stop the pin hole @ the end of the weld

the black stuff is just a fact of life when welding ss try puting another ss plate close but not touching the back of the plate your welding or if you have some put some copper flush on the back

to put your mind @ rest grind the back of your test welds and you will see 1 that the black stuff is reet hard stuff and 2 that all is shiny under it

hope some of my yammering is useful

 

[Rich.]

Yep, id say slightly too muh heat, which is why you have greyish welds as opposed to yellows/bues/purples or whatever.

As a guid, with a sharp tungsten, id be welding around 30a - 40a on stainless of that thickness.

Rich

 

[skrall]

Thanks for the comments, have done a few more, and they are looking a lot better (but cameras broken)
Turned the post flow to 3secs as sugested, and no pin hole at the end. Who'd have thought all those knobs on the front of the machine had a purpose

Also been doing alot of fusion welding on 16guage stainless pipe, and have found that the welds are coming out a lot better keeping the amps high(50amps) and moving quicker. Does this sound right? Will get some pics up when I get a camera sorted.

Cheers
Steve.

 

[shenion]

3 secs still seems low for post flow. Mine is at 20

I do find higher current and moving faster makes for more consistent welds and overall less heat input.