Dipping and Moving

[Seano]

I have now got the tig thang just about sorted...ie no tungsten touchdowns, good fusion, full penetration is coming good too, my only question is to the experienced tiggers, when dipping and moving is there any hard and fast suggestions for the amount of dips in the pool before moving...? and how far along the pool should your tip move be...?

I know you should be guided by heat and the way the weld is looking at any particular time, its just that sometimes I get lovely convex ally scales the same distance apart and all the same width and sometimes it looks like it is just a fusion run, with no dipping at all.

I suspect that I am either not dipping enough to keep the buildup of the convex scale, or dipping to much and not moving enough therefore in reality keeping just one big pool flowing.

Sorry if this is not very clear, I have tried to make it as understandable as possible, anyways.. you experienced guy's will get the pic instantly....

Sean.

PS sadly most of my ally work is done on old reused cast ally wheelchair footplates... not very conducive to improving ones ally welding skill....

 

[hotrodder]

You need to feed some filler into the puddle with aluminium rather than just dab it. Spacing... absolute minimum overlap of 50%, 70% is better. I move at a reasonably consistant speed where possible rather than dip, move, pause and dip.

It takes a little while but you need to be able to take in everything you're looking at- puddle, tungsten, the weld behind the puddle.
It's a bit like learning to drive in that respect- to begin with it's hard not to focus too much on one aspect, after a while you take in everything within your visual field without realising it. Those traffic lights i just went through, they were green weren't they?!

From the pics you posted previously you're almost there, cast is generally more fussy to weld than wrought- get yourself some fresh sheet or plate and (chances are) you'll be better than you thought

Weld some coupons, sand the cap flush and do some bend tests. This is a sample did on WW as there was some discussion about the 'oxide line' that's visible in the root bead. Bend radius for Al depends on alloy to some extent but 5T would be a general guide- smooth radius on all edges

 

[Kiwi K]

Hi Mr H,on last pic for bend test did you allow ally to go cold or was it still warm?(personal curiousity) cheers Kiwi.

 

[hotrodder]

It was cold, needed some 'persuasion' to conform with the die (which is the source of the marks) as the HAZ is softer than the rest of the piece. Can't remember for sure but i think the bend radius was a bit tighter than ideal- had to make do with what was kicking around