Weld construction durations 1

[DRW75]

Hello all,

Does it take much more time to weld say a 6mm fillet versus a 4mm fillet assuming that of course only one pass is used to form each weld.

So say you use a 1/8" rod to form the 1/4" fillet and say use a 5/64" rod to form the 5/32" fillet.

I do not have much actual experience with welding procedures, but it would seem to me to be about the same time - the only main difference is more amperage for the heavier fillet...

thanks

DRW

 

[dbuzz]

Here are some hour-rates for continuous fillet welds from the Australian Steel Institute publication Costing of Steelwork from Feasibility Through To Completion (Steel Constuction, Vol 30, No 2, 1996).

General Purpose, Short Weld (<250mm)
6mm 0.3 hours/metre
8mm 0.6 h/m
10mm 0.9 h/m
12mm 1.2 h/m
15mm 1.8 h/m

General Purpose, Long Weld (>250mm)
6mm 0.2 h/m
8mm 0.4 h/m
10mm 0.7 h/m
12mm 0.9 h/m
15mm 1.4 h/m

Structural Purpose, Short Weld (<250mm)
6mm 0.3 hours/metre
8mm 0.7 h/m
10mm 1.0 h/m
12mm 1.3 h/m
15mm 2.0 h/m

Structural Purpose, Long Weld (>250mm)
6mm 0.25 h/m
8mm 0.5 h/m
10mm 0.75 h/m
12mm 1.0 h/m
15mm 1.5 h/m

http://www.steel.org.au/pdf/sc_v30n2_june1996_steel_costing.pdf

 

[DRW75]

Thanks dbuzz,

I find it strange that the difference in time for a 6mm & an 8mm fillet is 2x. Isn't an 8mm still only one pass with a 4mm (5/32") rod?

DRW

 

[dbuzz]

It's still one pass but the welder is laying down a lot more metal. However, like you, I wouldn't have thought it would take twice as much time.

 

[DRW75]

Exactly what I was thinking, now if you look at the 10mm, which is probably made of three passes of a 6mm, it makes sense since it is about 3x the base time (although you might expect a little bit longer, since they have to clean the slag from the weld after each pass... don't they?).

This must assume that the 8mm is made of 2 passes with a 3mm rod...

DRW

 

[HgTX]

Keep in mind that the welders may not go switching different size rods for different size welds, so you may not be able to compensate for larger weld size with larger rod size. They'll likely have one box of rods out there.

Hg

 

[DRW75]

Fair statement HgTX - So you'dd think that they would just say use a 3mm rod on an 8mm fillet (say cause that's what they have on hand), but make only one pass by putting down more weld (i.e. going more slowly)... That makes sense, but I didn't think you were allowed to make the weld much larger than 2x the rod?

DRW

 

[HgTX]

I honestly don't know at what point they'd break out another box. That's anothing thing to consider when changing weld size though.

Hg