Im practicing for a UA 5g pipe test.6" sch 40 steel pipe.1/8" 6010 rod for the root,downhill,about 75 amps,might be a tad much though.I can use either 7018 uphill or 6010 (either direction) for the hotpass.I used 7018 uphill with a slight weave (holding the sides) & burned a hole through the root.Maybe run two small stringers with 7018 uphill concentrating the heat on the bevels (narrow groove)?Faster travel speed?Just trying to figure out which rod is best for hotpass,amps, and what technique works best?
- Otto Nobedder
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Joined:Thu Jan 06, 2011 11:40 pm
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Location:Near New Orleans
I'll share my personal preferences, which may not work for you, so consider this "food for thought" rather than advice.
For a 1/8" 6010 root (up or down), I like the gap tacked at 1/8 so it draws just a bit tighter, and only a narrow land. I also go much hotter; I like 105A so I can go to 1/8" 7018 without changing settings. Given the option, I'll do the hot pass 6010 down, also. At 105, though, it's also not difficult to blow through the root, unless you move fast.
At this point, though, you're not trying to deposit a great deal of metal. You should not try to much more than double the thickness of the root, and focus the heat on the sides (as you are doing) to have a place for the excess heat to go. Picture that cross-section of a double-vee weld, and think of the narrow band of metal in the root ahead of your hot-pass puddle for heat to try to escape through.
You didn't say... If you are using 3/32 7018 for your hot pass and cap, I find it harder to judge just how much metal I'm putting down versus how much heat I'm putting in the metal, but that's probably from being accustomed to the heavier rod. When I don't have the option, and must do a 7018 hot pass, I focus more on tying the root up the bevel than on putting much metal down.
two cents...
Steve S
For a 1/8" 6010 root (up or down), I like the gap tacked at 1/8 so it draws just a bit tighter, and only a narrow land. I also go much hotter; I like 105A so I can go to 1/8" 7018 without changing settings. Given the option, I'll do the hot pass 6010 down, also. At 105, though, it's also not difficult to blow through the root, unless you move fast.
At this point, though, you're not trying to deposit a great deal of metal. You should not try to much more than double the thickness of the root, and focus the heat on the sides (as you are doing) to have a place for the excess heat to go. Picture that cross-section of a double-vee weld, and think of the narrow band of metal in the root ahead of your hot-pass puddle for heat to try to escape through.
You didn't say... If you are using 3/32 7018 for your hot pass and cap, I find it harder to judge just how much metal I'm putting down versus how much heat I'm putting in the metal, but that's probably from being accustomed to the heavier rod. When I don't have the option, and must do a 7018 hot pass, I focus more on tying the root up the bevel than on putting much metal down.
two cents...
Steve S
Not sure what type work it will be in the future,just practicing for two timed UA tests right now.One is 6010 downhill all the way,the other is 6010 root & 7018 out.I have always used a 3/32 gap with about a nickels thickness for a land.105 amps sounds a little crazy to me,but i'll try it (downhill).That travel speed has gotta be fast,whip and pause technique?T pattern?As for the 7018 i've been using for the fill & cover,its only 3/32 with a slight weave uphill for the hotpass at 90 amps.Burnt hole through root,wont try that again
- Otto Nobedder
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Location:Near New Orleans
When I do a root at 105A, the technique is dirt-simple. Jamb it in like you're trying to burn through, and drag it down. No weave, no whip, nothing. Just push and drag.
No two welders do much of anything the same, though.
Here's a sch 80 root in 12", 37* bevel, about a dime's thickness for land, done that way (wire-wheeled for the camera).
No two welders do much of anything the same, though.
Here's a sch 80 root in 12", 37* bevel, about a dime's thickness for land, done that way (wire-wheeled for the camera).
Wow thats nice!My root is always flat on inside,sometimes i have a little suckback,sometimes not.For the most part its ok though.I've never had a root look like that on the inside.I'll try runnin hotter and faster and see how it turns out.Same technique for the hotpass right?6010 & 7018 amp settings?
- Otto Nobedder
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Weldmonger
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Joined:Thu Jan 06, 2011 11:40 pm
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Location:Near New Orleans
The rod will dictate the speed in this technique. There's more force on the "push" than the "drag"; The rod will move at it's own pace as the flux melts away, and the arc is occurring almost inside the pipe--- When you have it right, it sounds like a hive of angry bees.
The hot pass on this one was also done 6010 down at 105A. No whip, just a rapid slight weave, holding the edges just a bit.
The fill & cap (remember, this was sch. 80) were 1/8 7018 up, also at 105A. (I'm rarely close enough to my machine to make adjustments conveniently, which is why I learned this method.)
This was done in the stands, not in a rack, but was not rolled (too heavy to bother, by myself)
Here's the finished product, including a temporary test-port reducer.
Steve S
The hot pass on this one was also done 6010 down at 105A. No whip, just a rapid slight weave, holding the edges just a bit.
The fill & cap (remember, this was sch. 80) were 1/8 7018 up, also at 105A. (I'm rarely close enough to my machine to make adjustments conveniently, which is why I learned this method.)
This was done in the stands, not in a rack, but was not rolled (too heavy to bother, by myself)
Here's the finished product, including a temporary test-port reducer.
Steve S