Need advice. Striking an Arc. PowerArc200

[performance]

Are you running DCEP and how many amps?

[Kansan]

Are you running DCEP and how many amps?

Yes, DC electrode positive around 70-80 amps on 1/8" Rod.

140 amps on that machine and it better be 3/8's" steel or thicker lol. Maybe i really am welding too cold to start with, but the welds look decent like they are flowing in good. I might start it hotter then dial it back once im rolling. I will also try a grinding wheel instead of wire wheel.

I know 7018 prefers clean, but I've never had this much trouble touching off an arc on any machine. sometimes its tap tap tap for 30 seconds before I get any hint of a spark. Seems like scratch start is worse. I probably should check the stinger and ground connection themselves.

[performance]

That amperage would be ok (but not great) for 6010, or 6011, but not for 7018. That would be ideal for 3/32" 7018, but you need a good 90 amps to get the rod working right with the 1/8" rod.

Is the slag peeling right up after the weld? If it isn't the amps aren't right. I'd suggest you drop down to 3/32" and see how it works with 7018 if you aren't welding something that would support the rod size and amps required to burn it.

The reason it is continuing to burn once started is the action of the arc force control. I would expect the amps are boosting themselves anyway up to a sustainable level.

[GWD]

Yes, DC electrode positive around 70-80 amps on 1/8" Rod.

140 amps on that machine and it better be 3/8's" steel or thicker lol. Maybe i really am welding too cold to start with, but the welds look decent like they are flowing in good. I might start it hotter then dial it back once im rolling. I will also try a grinding wheel instead of wire wheel.

I know 7018 prefers clean, but I've never had this much trouble touching off an arc on any machine. sometimes its tap tap tap for 30 seconds before I get any hint of a spark. Seems like scratch start is worse. I probably should check the stinger and ground connection themselves.

As already discussed, 70-80A will barely get a spark. You may be laying metal on metal with very little penetration at that level. Sure, it looks good but it is not really a "weld".

Your idea to start hotter (MUCH hotter) and then dial back is definitely worth a try.

[DaveO]

If it's helpful, Jody C's video from last week is specifically about practicing with 7018 electrodes.
http://welding-tv.com/2015/01/27/701...at-horizontal/

As others have suggested, note in the video that he is running at 135 amps on an inverter machine, and gives advice about restarts. (He also talks about hot start and arc dig features, consistent rod angle, keeping a short arc... his usual pantload of knowledge.)

As a *general* rule of thumb, you can set amps to match the electrode: 1 amp per .001", and adjust as needed from there. As Mark wrote, when amps are set correctly for 7018 the slag peels off... also as noted in Jody's video. Good luck with it!

[Grafted]

Yes, DC electrode positive around 70-80 amps on 1/8" Rod.

140 amps on that machine and it better be 3/8's" steel or thicker lol. Maybe i really am welding too cold to start with, but the welds look decent like they are flowing in good. I might start it hotter then dial it back once im rolling. I will also try a grinding wheel instead of wire wheel.

I know 7018 prefers clean, but I've never had this much trouble touching off an arc on any machine. sometimes its tap tap tap for 30 seconds before I get any hint of a spark. Seems like scratch start is worse. I probably should check the stinger and ground connection themselves.

I have a powerarc 200 , I use 70-85 for 3/32 rods and a Min of 90 amps on 1/8 7018. I think you are a little cold.
I am using 7018 Lincoln e rods.

Tom