- Thread starter Micky89
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zardoz
Old school Socialist
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Too high amps sometimes causes it. Or...
Maybe move the rod a tad closer.! holding the rod too far from the pool can cause undercut (this sounds back to front, but bear with me) But if i remember correctly, too long an arc causes the metal pool to heat up, as the arc fights to maintain, if you move further away and you get a more firece arc. Hence the undercut. (unless I just dreamed this one night ? and I'm sure someone will be along to declare this as rubbish, if i did) Been a while since my city & guilds. I tend to Arc weld by ear these days. (ie: If it looks right and 'sounds right' then its probably ok)
Also make sure your rod angle is correct, and not too flat keep it up high..
ps: Just a thought, but what rods are you using
Maybe move the rod a tad closer.! holding the rod too far from the pool can cause undercut (this sounds back to front, but bear with me) But if i remember correctly, too long an arc causes the metal pool to heat up, as the arc fights to maintain, if you move further away and you get a more firece arc. Hence the undercut. (unless I just dreamed this one night ? and I'm sure someone will be along to declare this as rubbish, if i did) Been a while since my city & guilds. I tend to Arc weld by ear these days. (ie: If it looks right and 'sounds right' then its probably ok)
Also make sure your rod angle is correct, and not too flat keep it up high..
ps: Just a thought, but what rods are you using
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Ah so if I decrease the amps then I won't get spatter? I'm welding 10mm channel to 25mm plate so what would you suggest?
Drains
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It depends more on the rods you're using and the position than the thickness of the material, unless it's thin stuff.
So what rods? Make, type, size?
They're ESAB 4.0 E6013
wheresmejumper
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it could be arc length as the undercutting practically disappears for a stretch,as does the spatter
Sorry mate, what is OCV?
Usually it's only on oil cooled arc welders that you can change OCV. They have two ranges. Buzz boxes are normally fixed at around 50 OCV. That's why they won't run lo-hy rods properly.
OCV is usually quoted for inverters but it isn't really an issue with DC.
Looking at those welds, I'd say the current was a bit high and maybe the angle of the rod too steep. It should be 45 or slightly less.
If you can position the work so you are welding into the corner of a V rather than an L, it's easier.
OCV is usually quoted for inverters but it isn't really an issue with DC.
Looking at those welds, I'd say the current was a bit high and maybe the angle of the rod too steep. It should be 45 or slightly less.
If you can position the work so you are welding into the corner of a V rather than an L, it's easier.
Lawnmowerboy
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The no load OCV is usually fixed but varies with arc length i 99% think?
Rrunnach
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OCV will make no difference to weld quality, it is there to iniciate the arc depending on rod spec and type.
Your problem is material thickness differential, 10t to 25t, something has to give, undercut on the 10t or, LOF on 25t.
Amp range, upwards of 110A, nearer to 150A as a guesstimate!
Your problem is material thickness differential, 10t to 25t, something has to give, undercut on the 10t or, LOF on 25t.
Amp range, upwards of 110A, nearer to 150A as a guesstimate!
decepticon
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rubbish in my opinion, it is quite possible to run a 6mm FW between a 6mm plate and a 60mm plate with no undercut.
OP do you weave slightly from side to side as you run out the FW? if so make the weave smaller and lower the rod angle so the rod is pointing slightly more towards the vertical plate. slow down the rate of travel can help too.
Rrunnach
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Your welcome................
backpurge
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Looking at the picture, the weld looks not too bad then you start to get undercut and excessive spatter, so something is altering part way along the joint. Think about what can alter whilst you are welding, arc length, angle, traverl speed etc.
You commented that "the undercut makes it harder to remove the slag" more importantly it is a potentially serious weld fault which can lead to total joint failure
You commented that "the undercut makes it harder to remove the slag" more importantly it is a potentially serious weld fault which can lead to total joint failure
backpurge
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Just out of interest...........why??????
its 10mm to 25mm the pieces are too thick for 1 pass as for the decrease in power,after the first pass the metal will be to hot to continue with same amps,if its too hot you will get undercut.if it was my joind i would bevel both pieces the 25mm more & it will be 3-5 passes. just me.
normspanners
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Are your rods dry? I find you can have problems if your rods have pick up moisture I keep open packets on top of my boiler and they come out warm !! seriously though dry rods can save a lot of problems, somebody was saying it looked of from the start but it looked the other way to me poss as the rod was drying/warming with passed current?
also maybe a daft question are you pushing or pulling?
also maybe a daft question are you pushing or pulling?
