10mm x 10mm bar butt joints -- advice required

[ljkenny]

How would you guys choose to TIG 10mm x 10mm bar using butt joints?

FYI: The work below was done at 80A.

I guess to improve penetration, I could use a bevel or a 'V' joint?

How do I prevent the edges from melting away (you can see where this has happened in the image).

Any constructive advice gratefully received.

 

[J.B. Welding]

When you get to the end of the run speed up your filler wire and have a short slope down time. Best to bevel a bit if it needs strength as otherwise you are just grinding away the weld.

 

[ljkenny]

Who said anything about grinding? Those are my welds.

What do you mean by speed up my filler wire? Put more into the weld puddle toward the end of the run?

 

[J.B. Welding]

Yes mate, as the corner tries to burn back feed in the filler almost constantly, then lift it out of the pool just before you come off the power. You need a pretty quick slope down time or that last bit of hazey current can cause a blob out again. If you prep first you can use lower amps and thus less will burn away.

 

[Mee]

If you bevel all four edges you can tack on each corner first then weld all four sides.

 

[ljkenny]

I'll try all your suggestions, thanks.

 

[Brad93]

Tack corners, weld outside edges first then weld the flats.

You need to either get your slope down set or use 4T

 

[ljkenny]

I see the T2/T4 switch, but I don't know what it's for.

 

[Richard.]

2t and 4t are just giving you the ability to use the trigger for 2 or 4 stages during welding.
2t or two stages
Stage one press trigger, slopes into main current.
Stage two release trigger, slopes down, lights out post gas.
4t or 4 stages
Stage one press trigger, start current.
Stage two release trigger slopes into main current.
Stage 3 press trigger, slopes into ending current for crator filling.
Stage 4 release trigger, lights out post gas.

 

[ljkenny]

Ooooo, niiice!

I'll give that a go too.

Thanks chaps.

 

[Richard.]

On short runs like that I wouldn't use 4t.
I'd just use 2t press and hold and set a down slope of my usual 2 seconds. As its down sloping get a final dab in to reinforce the end of the run then back step away from the corner as the current phases out to zero.