Some runs in my new job

[SiPMerlin150]

Just getting settled in on their equipment as the MIGs are looking to be 20 years old! (as confirmed by some of the workers.!) Some of them love welding their tips up and slipping wire off the rollers (as I frustratingly found out)

I'm responsible for getting the box section in and welded up for truck chassis.

 

[backpurge]

Well done fella, are those welds vertical down?

 

[Lawnmowerboy]

Very nice, all downhand I take it? bit too much torch angle?

 

[SiPMerlin150]

They want it all done vertical downwards, tried it upwards, just runs off like water (1.mm wire @ 274 amps 26 volts) Torch angle was more for the easy of visibility as lighting was rubbish apart from when you strike up.

 

[Welderpaul]

Vertical down?

 

[Woody.v8]

Vertical down?

You arnt "That" surprized are you?

 

[SiPMerlin150]

yep with a 3mm open root, so plenty of penetration going on there for sure.

 

[Lawnmowerboy]

Vert. down feels nice but weld characteristics can be a different story. Had a load of steel van vaults come in at work where the welded seam running down had split. Complete lack of fusion only on 2mm too. 3mm is a fair old root gap so should be OK!!

 

[SiPMerlin150]

Theres a lot of amps too, if you move too quick it will leave nasty undercut all to easily, but keeping it steady, the wire melts in and fills the void between the two plates nicely

 

[blenkie1]

What are the wagons being used for? Used to work building car transporters and no way would we be allowed to weld downhand. I know when I did my weld tests we were allowed first run to come down hand (with a gap) and then a run going up.

 

[SiPMerlin150]

What are the wagons being used for? Used to work building car transporters and no way would we be allowed to weld downhand. I know when I did my weld tests we were allowed first run to come down hand (with a gap) and then a run going up.

gas cylinders

 

[defender dan]

I take it welding downhand for structural work is unusual then ? When I did my mig welding course at college our vertical butt weld on 2mm plate (can`t recall the gap) had to be done upward`s. Is there a different test/coding for vertical down ?

Regard`s, Dan.

 

[Lawnmowerboy]

Welding vertical down is a quick easy way of welding as gravity pulls the bead down faster but can very easily lack fusion and penetration...

 

[backpurge]

yep with a 3mm open root, so plenty of penetration going on there for sure.

Firstly, congrats on the new job, know you've been looking for a while, really hope it goes well for you

A gap on a fillet weld doesn't help penetration, in fact quite often the opposite happens. Ideally you want the joint as tight as possible.

Don't confuse the weld metal "falling" through the gap with penetration, unless it has fully fused into both sides of the joint it isn't a penetration bead and this very hard to achieve on a vertical down joint especially where you are welding 2 different thicknesses together

At the end of the day it all depends what the joint is designed for, if it is not structural then no sweat

 

[backpurge]

I take it welding downhand for structural work is unusual then ? When I did my mig welding course at college our vertical butt weld on 2mm plate (can`t recall the gap) had to be done upward`s. Is there a different test/coding for vertical down ?

Regard`s, Dan.

Yep two separate tests, also, not wanting to be picky but people are getting a little confused with their terminology, downhand is welding in the flat position and not vertical down

 

[dannyp]

downhand - aka flat is the usual position.

V down is fast be weack,

V up is strong but very slow

Flat is nice and fast and strong

 

[Drains]

They want it all done vertical downwards, tried it upwards, just runs off like water (1.mm wire @ 274 amps 26 volts) Torch angle was more for the easy of visibility as lighting was rubbish apart from when you strike up.

You'll never run neat vertical up with solid wire on more than about 19v (I can't get a good looking weld on over 17v). You might get more speed and volts with pulse and/or flux cored.

Vertical down gives the smoothest, best looking and weakest welds. To be avoided if full strength is required!

 

[shenion]

AT that settings, it would be spray transfer. Vertical down and flat are the only positions people use in spray mode.

As spray transfer has higher penetration and fusion heat than dip transfer, downhand is not a problem. Saying it is weaker is not correct; you adjust the weld current for the process used so it has the same heat as other positions.

 

[matt1978]

Spray is also used on Overhead position if the material thickness dictates.

Vertical down is commonly used (in the UK anyway) on applications such as truck trailer construction, skips, containers etc but its definitely not as strong as a vertical weld made correctly on material of the same thickness.

It's acceptable for use on material up to about 3mm thick and also its acceptable to come vertical down when putting a root in with Mig in Dip transfer for a open butt weld etc but the following runs (fill and cap) should be put in vertical for maximum integrity and strength.

I don't think you would be able to get a Qualified welding procedure based on vertical down on anything more than 3-4mm especially IF the joint was load bearing.

When I was on the tools one of my first jobs was to go out to Norway with a group of others to a construction site to replace all of the vertical down mig on the structural steel (that had been pre fabbed/welded in the UK) with Vertical up MMA because the quality inspector would not accept vertical down mig on structural steel.

 

[SiPMerlin150]

I keep slipping up by putting good runs down but always seem to have a problem with 'cold lap' on the edges of the bead. If I weave, I get it, if I'm in one place I get it, if I'm traveling too slow, the weld concave's and looks under filled, and If I'm too fast it looks too thin. Not blaming the equipment about this face, except the welders are really old and most sets cause problems. One has erratic wire feed, it will run ok for a bit, then the wire feed drops out causing an long arc, splattering the weld everywhere. The wire comes out in a corkscrew fashion, another welder likes to constantly burn back and weld its tips. others have covers missing or wire spool brakes missing etc. Had some frustrating moments where I thought about throwing in the towel a few times this week. So frustrating when the sets are holding you back.