butt welds?

[decepticon]

hi everyone,
i have an inverter and mosa welding generator which i am trying to get the hang of prior to hopefully passing exams etc.
i am becoming capable at vertical and horizontal fillets and overhead fillets, as well as most butt welds where the work piece is laying flat, but in my line of work (steel erector) i need to master a butt weld where two plates/columns are vertical and the butt weld is running horizontal.
i have v'd the two edges and can successfully run the root weld in (2.5mm 6013's at 70A) but im struggling to fill and cap (3.2 6013's80A).
is it better to weave up and down when filling or to run two stringers along the joint. if i weave up and down the new metal tends to run down slightly and the top of the butt is undercut.
what would people on here do? (hopefully the question makes sense)
cheers
neil

 

[Tigman]

weld it in 3 runs , put the root in , then one first run at the bottom , second run just above , and third run at the top , no weaving !

 

[decepticon]

a bit disapointed that i had to wait a full 6 mins before a reply!! thanks for your input, it is kind of what i expected. i taper each edge approx 30deg, would that sound about right? or should this be opened up to prevent inclusions on the final upper run/s at such an acute angle?
cheers
neil

 

[runnach]

i taper each edge approx 30deg, would that sound about right? or should this be opened up to prevent inclusions on the final upper run/s at such an acute angle?

cheers
neil

Yep 60 degree inclusive angle is correct. If around 6mm thick, root face I'd say max 2.5mm (core thickness of rod) with 2.5 gap.

If your struggling with caps using 3.2's, caps with 2.5's, stringers all the way.......

No idea of Matl thickness, so cant comments on approx amps?

Cheers..........

 

[Tigman]

when I was taught horizontal weld, edge prep was only on the bottom piece, top plate left square so when welded no undercut on top plate as more metal there to start with ! Im not sure what the angle of prep should be perhaps one of my more learned friends will let you know !

 

[runnach]

Interesting, I do V with pipe and plate, last year there was a competition where lads from other college prepped pipe with single vee at btm. Our lads, as I described V.

Every coupon snapped on single vee prep and, visually they looked sound.

I should add, V 1G to 4G with plate over 5mm T.

 

[Paul.]

I was always taught, and used to teach, a vee prep with a shallower angle on the lower plate to provide a platform or step to weld on, like all things welding always more than one method, if it works for you do it.

 

[Tigman]

That doesnt sound good ! but thats how I was taught , mind you never get to weld anything like that these days ! V prep it is then

 

[decepticon]

thanks to everyone for the much valued info, double v's it is then. plates generally 6-10mm.
cheers

 

[Childress Enterprises]

hi everyone,
i have an inverter and mosa welding generator which i am trying to get the hang of prior to hopefully passing exams etc.
i am becoming capable at vertical and horizontal fillets and overhead fillets, as well as most butt welds where the work piece is laying flat, but in my line of work (steel erector) i need to master a butt weld where two plates/columns are vertical and the butt weld is running horizontal.
i have v'd the two edges and can successfully run the root weld in (2.5mm 6013's at 70A) but im struggling to fill and cap (3.2 6013's80A).
is it better to weave up and down when filling or to run two stringers along the joint. if i weave up and down the new metal tends to run down slightly and the top of the butt is undercut.
what would people on here do? (hopefully the question makes sense)
cheers
neil

well if your still having a problem with under cut try turning your machine down a few amps and consider changing your rod angle