JET - LH 78 MR-RSP vs. Lincoln 7018 AC-RSP - what is the difference?

[FlyFishn]

These are both 7018 rods. Both are DC+ and AC. Aside from the 7018 AC-RSP having more dust on the boxes = had been around a while, we were not able to come to much conclusion as to what the difference in the rods was when I was at the shop. Any ideas? It appears the more commonly sold rod at the LWS I got them from is the LH 78 MR-RSP. I imagine there is a reason - but not sure what the reason is yet.

I bought a 5lb box of 3/32" of both to try. I am not sure if my inverter will like one or the other. Since the LH 78 MR-RSP's were more popular I figured I'd get a box of 1/8" and 5/32". Chances are if I am welding at home its on the tombstone and it has no problems with running any rod I've thrown at it. The inverter is a different story... and I am going to pair the 3/32" rods for it as they run on lower amps.

[MISSING LINK]

The green box 7018 is a lower diffusible hydrogen limit, "H4R", and although it's labeled that it will run on AC current the blue box stuff will run on AC better. And the blue box stuff has a higher diffusible hydrogen limit "H8", and looks to be smoother on AC than the green box. Either way, if left open and not in a oven, both soak up moisture. But if you are not doing any sort of work that follows a strict welding code, they will both be fine. A lot of people have used 7018 that is never been in an oven without any problems. But your mileage will vary, just my two cents.

[FlyFishn]

Thanks for the input.

I haven't broken the seals/stickers on the boxes just yet but those plastic sleeves themselves are not sealed packages. All the other rods I've bought in those (6010, 6011, 7014, and 6013) the rods are just bare in the sleeves. So unless the 7018's are unicorns I suspect they are the same = don't ship in sealed containers anyway.

No code work here. As long as I can get good beads without porosity I'll be in good shape. The stuff I have run I get porosity on most beads - usually at the starts. I am hoping these new rods take care of that. I am pretty sure the stuff I was using is an AC version, I got the box from home depot. I will check it later. The rod has "7018 H8" on it, but that isn't the whole description that the box has I don't think...

[FlyFishn]

Just a wild idea here...

Is the "preferred" polarity always listed first in the list of polarities for a given rod?

If that is correct - on the 7018 AC-RSP's AC is listed first, then DC+. That would appear to describe the manufacturer suggesting AC is the preferred polarity for those rods. However, I don't know if I buy that - I am not sure I would buy any rod to be preferably run on AC? Acceptable results, yes, but I would imagine DC would trump the results for any rod over AC.

The only exception to that rule being magnetized base metal where DC would cause erratic arc characteristics and AC would be easier to control. In that case, the arc and result bead quality would still be degraded over DC - it would just be that AC would be controllable whereas DC would not.

[Kelvin]

When in doubt, I've found that by Googling the exact product name and SKU number, you can usually get far more information than you even wanted about composition, strength, ductility, recommended polarity, test results, etc., of nearly any filler/rod.

[albrightree]

RSP - Retail Service Package Available at most fine retail stores. These are 2 of the twenty types of LH rod that Lincoln makes for North America, they have many more in the UK, EU, and elsewhere.
The AC ones are usually in the big box stores right next to the AC-225(for now). the DC only's usually at the welding shops. My local tractor supply usually only have the AC/DC Hobarts on the shelf. This allows more people to use the rod, especially guys with and old buzz box.

None of the inverter welders I've run so far has had a problem with 6013, 7014, and 7018. The only differences I've noticed between 7018 rods is, what amperage they run well at, how hard the slag is to remove(some are really difficult), and how some rods have the flux crumble while welding if they aren't so new (7018).

I've run the Lincoln, Hobart, ESAB and Messer 7018 rods without any major problems on my Lincoln 210MP (inverter), or even my Dayton AC/DC buzzbox (running on 208v). Both struggle with Different 6010's

Your experience may vary....

So, burn some, and let us know what you think. I don't think you 'll find anything transformational here, posting some pic's would be nice too. https://www.weldingweb.com/images/smilies/smile.gif

[FlyFishn]

Thanks for the info. I was working on calibrating a saw today and was going to burn a few rods afterwards to try them but it started sprinkling. Too much rain headed this way now to set up so I'll wait for tomorrow.

On a side note - the original box of 7018 I got (from home depot) is the same 7018 AC-RSP, just in a different box (and different size - the new stuff is 3/32 and the box I got a while back is 1/8"). So apparently the stuff the LWS gets is just in a different package. I am guessing the LH 78 MR-RSP version will run better as the other stuff is what I'm getting porosity with. We'll see.

[M J D]

Save the frustration and get some Lincoln Excalibur 7018-h4r or some esab atom arc and call it a day. That 7018AC crap is just a work a round that doesn't work very well. If your getting porosity on the start it's probably more technique than the electrode. Pulling a long arc at starting will almost guarantee porosity. Start ahead of where you want to start, drag it back towards the desired start spot . If you do have some porosity where the initial strike is , it should burn out with the slag when you cross back over it.

[MISSING LINK]

My vote also for what M J D said about your light up. Start ahead a bit, then back up and burn through your start up.

I will run whatever brand rod I have on hand at work, results for me are close to the same. If I had my choice it would be ESAB Acclaim, ESAB Atom Arc, Lincoln Jetweld LH-70 and if I must bring myself to use it, Excalibur. Most times if Excalibur gets put in my truck, I drive straight to the dumpster and toss it. Sorry to say that, but I don't care for the way Excalibur runs. I am weird I guess. I also burn a far amount of 6013 for certain repairs as it yields the best results for me at times.

For home use I buy Washington Alloy plain-jane 7018 as it runs nice on my AC machine.

As for polarities some projects a DC+ rod or AC rod ran on DC- is what works the best. Practice and familiarity will get you used to when to use that scenario.

[MISSING LINK]

Deleted double post...

[Welder Dave]

Esab Atom Arc is pretty nice to burn and they have another 7018 above it (Acclaim) for being nice to burn. They also have OK 55 from Sweden that is pretty popular because it's less expensive than the Blueshield. If you were in Canada, Blueshield 7018 is KING. Lincoln Excalibur is further down the list as far as popularity. Don't need to worry about the diffusible hydrogen levels, just keep the rod dry. If you were doing anything requiring a rod oven you wouldn't have to ask on here.

https://www.esabna.com/7018/index.html

https://canadaweldingsupply.ca/produ...red-electrodes