It is currently Sat Nov 18, 2017 12:19 am Advanced search

Can Lincoln Electric 3/32 7018 electrode be also used DCEN?

Stick Welding Tips, Certification tests, machines, projects

Can Lincoln Electric 3/32 7018 electrode be also used DCEN?

Postby gr8gary1 » Tue Nov 14, 2017 7:29 pm

Trying to build a desk for my wife. Getting a lot of porosity and don’t know why. On my ranger 10000, the amps are set to 90 and the dial all the way to just above five. These are new off the shelf electrodes. I am holding a tight arc and good to me travel speed. I also have a bad wrack to it. All the cuts are dead nuts on. I put the gussets on the bottom frame prior to welding the legs to the top frame and I think it’s putting strain on it not allowing it to level out. Can I get some help. I can upload more pics if necessary when I get home in a few.
Attachments
847998FA-89B7-43D6-8AE8-579AB62C3CC0.jpeg
The frame in all its glory:/
847998FA-89B7-43D6-8AE8-579AB62C3CC0.jpeg (57.86 KiB) Viewed 104 times
gr8gary1
New Member
 
Posts: 16
Joined: Fri Sep 16, 2016 3:44 pm
Location: So Cal

Re: Can Lincoln Electric 3/32 7018 electrode be also used DC

Postby gr8gary1 » Tue Nov 14, 2017 7:50 pm

These are Lincoln Electric 7018 AC-RSP electrodes by the way. Refers to the pic for more clarity.
Attachments
23DB78F4-8912-4CFA-9147-C50134DD75A0.jpeg
Electrodes
23DB78F4-8912-4CFA-9147-C50134DD75A0.jpeg (46.55 KiB) Viewed 95 times
gr8gary1
New Member
 
Posts: 16
Joined: Fri Sep 16, 2016 3:44 pm
Location: So Cal

Re: Can Lincoln Electric 3/32 7018 electrode be also used DC

Postby MinnesotaDave » Tue Nov 14, 2017 8:23 pm

Normally on DC those are run DCEP

Around 90-100 amps is where I usually run 3/32" 7018.
Sometimes as low as 85 amps.

edit: I looked up your machine. You're set on the 40-90 amp range so you're only at about 65 amps or so. Pretty low for 3/32" 7018.
Dave J.

Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

Airco 300 - Syncro 350
Invertec v250-s
Thermal Arc 161 and 300
MM210
Dialarc
Tried being normal once, didn't take....I think it was a Tuesday.
User avatar
MinnesotaDave
Weldmonger
 
Posts: 1594
Joined: Sun Oct 27, 2013 10:57 pm
Location: Bemidji MN, U.S.A.

Re: Can Lincoln Electric 3/32 7018 electrode be also used DC

Postby gr8gary1 » Tue Nov 14, 2017 8:38 pm

Thanks for the prompt reply Dave. I appreciate the information and will make the changes. I move the amperage down due to the fact that I kept blowing through this material is less than 1/8 inch thick so I was trying to keep from blowing through. I will adjust my technique and try it with the higher amperage. I am getting good penetration however, But with a lot of porosity.
gr8gary1
New Member
 
Posts: 16
Joined: Fri Sep 16, 2016 3:44 pm
Location: So Cal

Re: Can Lincoln Electric 3/32 7018 electrode be also used DC

Postby Farmwelding » Tue Nov 14, 2017 8:45 pm

Have any pictures of the porosity and the electrodes? Have they been exposed to a lot of moisture?
A student now but really want to weld everyday. Want to learn everything about everything. Want to become a knower of all and master of none.
Instagram: @farmwelding
Nick
Farmwelding
Weldmonger
 
Posts: 1331
Joined: Thu Mar 10, 2016 11:37 pm
Location: Wisconsin

Re: Can Lincoln Electric 3/32 7018 electrode be also used DC

Postby gr8gary1 » Tue Nov 14, 2017 8:55 pm

Farm welding, I will get some pictures when I get home. As I said in my original post, these are brand new electrodea so I have no idea what their exposure has been. I bought them at Lowe’s so anything is possible.
gr8gary1
New Member
 
Posts: 16
Joined: Fri Sep 16, 2016 3:44 pm
Location: So Cal

Re: Can Lincoln Electric 3/32 7018 electrode be also used DC

Postby gr8gary1 » Tue Nov 14, 2017 9:43 pm

Ok here is a pic of a little porosity and yes, under cut. Also a pic of the thickness. I believe it it just over 1/16”
Attachments
CAFC1A91-0709-49CD-AE70-435BAEEDA9CA.jpeg
CAFC1A91-0709-49CD-AE70-435BAEEDA9CA.jpeg (27.22 KiB) Viewed 84 times
05BA5510-107F-493C-B5FF-51604949A91D.jpeg
05BA5510-107F-493C-B5FF-51604949A91D.jpeg (34.92 KiB) Viewed 84 times
gr8gary1
New Member
 
Posts: 16
Joined: Fri Sep 16, 2016 3:44 pm
Location: So Cal

Re: Can Lincoln Electric 3/32 7018 electrode be also used DC

Postby Poland308 » Tue Nov 14, 2017 10:06 pm

Are you getting porosity only on the last weld that is sealing up the tube? Oil contamination will also cause holes like that.
I have more questions than answers

Josh
Poland308
Weldmonger
 
Posts: 2271
Joined: Thu Sep 10, 2015 8:45 pm
Location: Iowa

Re: Can Lincoln Electric 3/32 7018 electrode be also used DC

Postby gr8gary1 » Tue Nov 14, 2017 10:20 pm

Poland308 wrote:Are you getting porosity only on the last weld that is sealing up the tube? Oil contamination will also cause holes like that.
.

I didn’t use acetone to clean it but I tried to make sure it was bright shiny metal. Just clarify though, this was scrap metal from my neighbor. Maybe there was something on it although there didn’t appear to be.
gr8gary1
New Member
 
Posts: 16
Joined: Fri Sep 16, 2016 3:44 pm
Location: So Cal

Re: Can Lincoln Electric 3/32 7018 electrode be also used DC

Postby Poland308 » Wed Nov 15, 2017 12:35 am

On real thin 1/8 or less I’d personally run a little colder than Dave. Just personally. I’d be at about 70-80. If there is any oily residue on the inside of the tube then it will get pulled through the molten pool as you weld. This can definitely cause porosity. Some kinds of Left over paint or any kind of zinc/galvanizing, same thing. If you weld the pipe or tube totally closed and don’t allow for hot air to escape then this can cause porosity as well, but usually only as your making the last stretch of weld. Rod condition is less likely. I have some 7018 that got rained on, the iron powder in the flux actually has started to rust. I use it for lots of non essential stuff with no porosity. However if the flux is soaked in oil, water, glycol, or cracking and flaking off in chunks either before or during a weld then it’s worthless and will also cause holes.
I have more questions than answers

Josh
Poland308
Weldmonger
 
Posts: 2271
Joined: Thu Sep 10, 2015 8:45 pm
Location: Iowa

Next

Return to Stick Welding/Arc Welding - Shielded Metal Arc Welding