Munkul
Jack of some trades, Master of none
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- 7,328
- Location
- Cumbria
So I was wondering this last week... I didn't get an answer so I wanted a specific thread for this...
Had a batch run to do of stainless steel legs, basically there are 240 butt welds and 240 fillet welds for the feet, so very very repetitive work, so very sensitive to any changes.
Using my new TIG set with a borrowed gas cooled WP26 sized torch which was an older demo torch the welding shop used for demoing TIG machines.
Used a standard size gas lens, with a No.7 cup, and about 7-8lpm gas flow.
With this setup, I had it DIALED. I mean, seriously. Every weld came out looking silver or gold, partly due to the pulse setup for minimal heat input. Never had it quite as good before.
Then halfway through this batch, I got my new watercooled torch and cooler, it's a WP20 sized torch, and i put a standard WP20 sized gas lens on it, and a No,.7 cup, again. Started welding again with exactly the same settings and amps.
Two things:
Firstly, the new torch ran 10-15 amps hotter than the old one. No ifs or buts, I had to dial back my programs by 10-15 amps to get exactly where I was before in terms of heat input, puddle and travel speed.
Secondly, the gas coverage was suddenly much poorer. I was going from silver/gold welds to blue/purple, even after the amps were turned down to compensate. I changed the gas lens for a different make, which did improve things a bit, and I played for AGES with the gas pressure and flow, eventually settling on 7lpm as best. But the average weld is gold, now, not silver.
I then tried a large WP9 gas lens, this thing is huge, way bigger than the standard WP17 gas lens, with a No.8 cup, and it was absolutely no better.
Torches - made by Lorch.
Gas lens - first one unbranded 45V44, second one Parweld (the better one)
cups - ceramic No.7's, 8's
All parts degreased with acetone, no oxides removed
So... what gives? I've never been too bothered by colours, as long as they weren't dull or grey, but for this job it seemed I had it "perfect" and now it's not.
Is it a given, that the smaller WP9/20 gas lenses don't do as good a job as a WP17?
The amps through the torch MIGHT be explained through the old demo torch, it did actually seem to warm up on the cable near the dinse connector a little bit, but I wouldn't have thought 200-300 watts lost...?
Had a batch run to do of stainless steel legs, basically there are 240 butt welds and 240 fillet welds for the feet, so very very repetitive work, so very sensitive to any changes.
Using my new TIG set with a borrowed gas cooled WP26 sized torch which was an older demo torch the welding shop used for demoing TIG machines.
Used a standard size gas lens, with a No.7 cup, and about 7-8lpm gas flow.
With this setup, I had it DIALED. I mean, seriously. Every weld came out looking silver or gold, partly due to the pulse setup for minimal heat input. Never had it quite as good before.
Then halfway through this batch, I got my new watercooled torch and cooler, it's a WP20 sized torch, and i put a standard WP20 sized gas lens on it, and a No,.7 cup, again. Started welding again with exactly the same settings and amps.
Two things:
Firstly, the new torch ran 10-15 amps hotter than the old one. No ifs or buts, I had to dial back my programs by 10-15 amps to get exactly where I was before in terms of heat input, puddle and travel speed.
Secondly, the gas coverage was suddenly much poorer. I was going from silver/gold welds to blue/purple, even after the amps were turned down to compensate. I changed the gas lens for a different make, which did improve things a bit, and I played for AGES with the gas pressure and flow, eventually settling on 7lpm as best. But the average weld is gold, now, not silver.
I then tried a large WP9 gas lens, this thing is huge, way bigger than the standard WP17 gas lens, with a No.8 cup, and it was absolutely no better.
Torches - made by Lorch.
Gas lens - first one unbranded 45V44, second one Parweld (the better one)
cups - ceramic No.7's, 8's
All parts degreased with acetone, no oxides removed
So... what gives? I've never been too bothered by colours, as long as they weren't dull or grey, but for this job it seemed I had it "perfect" and now it's not.
Is it a given, that the smaller WP9/20 gas lenses don't do as good a job as a WP17?
The amps through the torch MIGHT be explained through the old demo torch, it did actually seem to warm up on the cable near the dinse connector a little bit, but I wouldn't have thought 200-300 watts lost...?