View Full Version : 7018 question
01-07-2005, 06:44 PM
yessterday i was welding all day with 7018 dcep no problem nice welds. today i noticed that i had been using 7018 ac rods. i was doing some practice, switched the machine over to ac , couldnt get a decent weld to save my life. i am pretty new to stick by the way. so any help would be appreciated thanks.
01-08-2005, 09:48 AM
I always use dc. unless stainless or alum. then of course must go ac. the 7018 is a great rod. and loves dc. switch it back and arc away......
01-08-2005, 05:57 PM
ok thanks i just didnt know if rods that were designated ac were only meant to be used on ac only. so i guess im ok on dc thanks
01-08-2005, 06:41 PM
There are a few rods that can't be welded with on either AC or DC depending on what it is. ( EX., 6010 won't do AC, ALu rods won't do AC ) I'm sure there may be something that won't do DC, but I haven't found it yet. Not in my field anyway.
The best way to tell if you are ok, is by the results. ( appearance and results of destructive or in-destructive tests ) If you get good results, you are most likely ok. If it is like trying to weld with a wet pencil, you may need to look at your current. It USUALLY either works, or it doesn't. There are always exceptions to every rule. I did some beautiful beads on some heavily magnetized exotic steel columns once. 1/8 8018W ( Atom Arc ) on DC. The beads were perfect....looking. Something about the combo of exotic steel and DC with a high chromium rod, gave me all the penetration of Elmer's glue.:eek: One tap with a big hammer and they popped right off.:angry: I looked up the ATSM #, switched to regular 7018 on AC and BLAMMO! Success! That one was the weirdest thing I've seen. Never seen it since, either, thankfully.
If you haven't already gotten one, get your hands on one of the many Rod Guides out there. Lincoln has some available on their site in .pdf format. They will tell you what's out there and the current types and ranges for each size. I've been doing this a long time and I still grab one every now and then. Nothing wrong with a cheat sheet in this work!:D
02-22-2005, 03:26 PM
If you have DC available, 7018 runs nice DCEP. Keep the rod nearly buried in the puddle. I think the AC rods spatter a little more even when run on DC, but it is nice to have the option, as I've had some issues with arc blow when working in tight corners, and switching over to AC is easier than trying 10 things to solve the arc blow.
I bake my 7018 in kitchen oven (electric) on max for several hours, and weld with the rods still hot from the oven.
You know about 7018 and moisture issues, right? If you are having trouble sustaining an arc on AC it might be a moisture issue...though I think the main reason to bake them is that if the coating is moist you are not making low Hydrogen welds.
02-23-2005, 09:05 AM
What precautions should you take when storing 7018 rods? Could they be stored in
an airtight container with silica granule packs? Is it necessary to use an oven before
02-23-2005, 03:26 PM
They are supposed to be shipped, stored and kept in airtight packaging. There is a bakeout process that calls for higher temps than you get with a household oven. There are also such things as rod ovens...though a lot of welding shops use an old fridge with a lightbulb for a heater.
A rod oven is one of those projects I might get around to someday. Seems like they cost a lot for what they are.
02-24-2005, 07:57 AM
Thanks Kevbo. Still not clear on the bakeout process- is it done by the factory or
the end user? What's a practical way for an occasional user of the rods to store them,
and should they be oven treated before using them? What temperature should be maintained in a homemade rod oven? If the temp is not critical, it seems like you could
use a golden rod (electric dehumidifier rod for gun cabinets) placed in an old ice chest.
02-24-2005, 09:55 AM
Storage: as per manufacturer. Most will include 225 to 275F in the recommended range.
Bakeout: Again, as per manufacturer. Some as low as 400F (Hobart guide, 1980ish), some as high as 700F (on the can of ESAB sitting in my shop) It is NOT recommended to rebake the electrodes. If you store them properly, you won't need to. Rebaking doesn't give you the same performance as rods that were properly stored, and the manufacturers lit I have read ALL prohibits more than one rebake.
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