Putting in 'torch time'

[inchpincher]

I've owned my Murex Tradestig 160 for about three years now and although I practised the basics in the beginning, I pretty much just pick it up now to do a job but usually walk away thinking 'it'll do but that could have been neater...'

So now I've decided to try to take it to the next level where people will say nice things about the welds and I think it's purely down to a bit of torch time and feedback from the experienced eyes on here. I've never done welding course in my life or been shown in person how to do things (although I've read and watched just about everything online!) so all comments, suggestions and tips are welcome no matter how fundamental...

First up was a piece of 42mm CHS MS, 3mm thickness. Chopped it up on the bandsaw and set about putting it back together. Penetration I was happy with although I got some sag from where I was starting a new bead and back stepped the torch to get rid of the ugly mound of filler from the previous beads end. I think this was down from practising Ali recently where I fill the puddle with filler as the bead ends to stop a crater forming... Comments? Consistency of arc length going around the tube was the part I feel needs the most improvement

 

[Bobbyspit]

are you purging the pipe?

 

[hotrodder]

No need to purge mild steel although a root gap would make for a cleaner and more consistant root profile. Angles of attack and arc length look like they were pretty consistant. With regards to craters... try and keep the arc moving during slope out. It's when you stop moving and then slope out that you get a crater or a large blob from filling it. Experimenting with slope times may halp too

 

[carlos420uk]

Looks pretty damn good to me I'm useless at pipe!

How many stop starts did you have to make to do one complete weld?

 

[inchpincher]

Thank you chaps. Like HR said, no purge as it's mild, good call on the down slope though, I use a pedal so I'll ease off a bit slower at the ends. The tube was tacked in 6 intervals so that's 5 beads per complete weld. I watched a vid where someone was making an inlet manifold and the jig stuck in my mind, basically pieces of upturned angle iron with a gap in the middle so you start welding with the tip of the torch nearly pointing directly at your body and then weld towards the crown of the tube. Remember this stuff is all comfortably sat on my bench so there's no excuses, i'm striving for better!

I did a quick butt weld on some strips of 16g MS today, experimenting with filler, speed, circle movements etc. Its ok I guess but still messy stop/starts and a bit too flat IMO.

All the steel stuff has had to be done with a 2.4mm thoriated tungsten because I binned the crap 1.6mm ones. I thought it was me for a long time but there was no consistency, the welds would bubble up for no reason.

Also put in a couple of hours on a piece of Ali, just changing speed, amps, tungsten stick out, filler feeding techniques, etc. The Murex machine doesn't have pulse or manual frequency adjustment so it's mostly human fettling. Hopefully as the hours clock up I'll start to really see things improve. And remember kids, don't wear a white t shirt unless you like the sunburnt neck look

 

[Bobbyspit]

looking good! I like the comment about the sunburn, I found out with burnt upper arms last month, note to self wear the jacket!

 

[Drains]

Looking neat Inchpinch. One question- what do the undersides of you butt welds look like? The penetration's the real test...(pretty good in the pipe mind you)

 

[inchpincher]

The penetration was a bit too much on the flatter welds (the top of the pic), it's sat on a piece of copper which 'saved' it, I'm gonna do a few more bits this evening. I carried on with some Ali practise earlier today, really focusing on the way the filler spreads to the edge of the bead which leads to a much more consistent result.

I've needed to up the gas a bit to 8 lpm as I felt the tungsten was getting contaminated even with a decent amount of post flow (using a gas lens btw).

Feeding the filler rod has improved dramatically, out of necessity really!

 

[Bobbyspit]

I did my first decent bit of welding this week at college, this is alloy water pipe, cut to an angle and welded back together for a bend for my water pipe (water rail) on my classic car. I am well pleased with my work, although my tutor thinks I should flatten it down and polish the pipe?