Hey guys first time poster. I'm practicing a 4" to 8" branch (fish mouth) schd 40 with 7018 root and 7018 all the way out. What tips and suggestions would you guys have in terms of gap, landing and technique for welding the root?
Thanks.
plain ol Bill
- plain ol Bill
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Guide
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Joined:Wed Apr 08, 2015 6:46 pm
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Location:Tenino, WA
Personally I would rather someone beat me with an oak club than to attempt a 7018 root on anything that they are going to NDT. Non critical joint that just needs welding - I'd double bevel, leave a 1/16 - 3/32 land, gap 3/32 and weld it w/ 3/32 7018.
Tired old welder
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CNC plasma cutter
Colorful shop w/
Red, blue, yellow, purple, and Hypertherm silver equip.
- Otto Nobedder
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Joined:Thu Jan 06, 2011 11:40 pm
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Location:Near New Orleans
Welcome to the neighborhood! A good question like that is a good place to start. Don't be afraid to stop by "member introductions", and tell us a bit about you.
If 7018 is all the WPS allows for the root, I'd gap it to the thickness of the rod, i.e. 1/8" gap for a 1/8" rod. It'll draw enough when you tack it that you can't push through unless you overheat it. The ideal bevel will vary around the circumference of your fish-mouth piece of the branch. This is a 90? Not a branch wye? At the short leg, the area top-center, 75* is a good bevel. at the long leg, the end of the fish's lips, you'll probably be closer to 30-35*, and transition your bevel between the two points. The goal is to have about the same opening angle to stick the rod in, all the way around. This helps for a consistent root, and makes a more even space for the fill and cap for a clean looking finish.
I'd aim for a land smaller than rod thickness. 3/32" for 1/8 rod, 1/16" for 3/32 rod. I'd also (for the root) run my amps at the top of the WPS allowance, with a significant drag angle, say 20-25*, so you can drag the flux on the joint for a very consistent arc-length and penetration.
Caveat Lector: I've never had to test with a 7018 root, so I can't speak for testing results with this method, and I'd think a practice piece or two is in order.
Steve S
If 7018 is all the WPS allows for the root, I'd gap it to the thickness of the rod, i.e. 1/8" gap for a 1/8" rod. It'll draw enough when you tack it that you can't push through unless you overheat it. The ideal bevel will vary around the circumference of your fish-mouth piece of the branch. This is a 90? Not a branch wye? At the short leg, the area top-center, 75* is a good bevel. at the long leg, the end of the fish's lips, you'll probably be closer to 30-35*, and transition your bevel between the two points. The goal is to have about the same opening angle to stick the rod in, all the way around. This helps for a consistent root, and makes a more even space for the fill and cap for a clean looking finish.
I'd aim for a land smaller than rod thickness. 3/32" for 1/8 rod, 1/16" for 3/32 rod. I'd also (for the root) run my amps at the top of the WPS allowance, with a significant drag angle, say 20-25*, so you can drag the flux on the joint for a very consistent arc-length and penetration.
Caveat Lector: I've never had to test with a 7018 root, so I can't speak for testing results with this method, and I'd think a practice piece or two is in order.
Steve S
- Braehill
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Joined:Sat Jul 06, 2013 11:16 am
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Location:Near Pittsburgh,Pennsylvania. Steel Buckle of the Rust Belt
Only tip I have is the try to get your starts and stops away from the high and low points of the fish mouth because this is usually where they cut the straps from for the test.
Do you have to lay it out by hand or are you allowed to use templates or is it already laid out for you? I have a few tips that help with the layout if you need them and they're allowed.
Is it inverted or welded out on top center?
These are things to know beforehand so you can practice. Most folks want to see what you're capable of doing with this test, but you'll seldom if ever do this kind of joint in the field. The test is the test though and it's better to go there loaded with the right knowledge.
Len
Do you have to lay it out by hand or are you allowed to use templates or is it already laid out for you? I have a few tips that help with the layout if you need them and they're allowed.
Is it inverted or welded out on top center?
These are things to know beforehand so you can practice. Most folks want to see what you're capable of doing with this test, but you'll seldom if ever do this kind of joint in the field. The test is the test though and it's better to go there loaded with the right knowledge.
Len
Now go melt something.
Instagram @lenny_gforce
Len
Instagram @lenny_gforce
Len