First time damascus WIP

90 amps DCEN with a 7018 would be way, way better than 90 amps with .030 flux core. It might be just as ugly until you got the hang of it but it would hold rebar to a billet.

 

That is not a true statement, however a lot of people recognize it as that as they see it as the inexpensive way to mig weld without the need for an external gas source and regulators. It's 'general' purpose is for use in an environment that is not conducive to using a shielding gas that would otherwise be blown away from the welding area by wind. Try using an unshielded wire shielded with gas in a windy environment. It'll be one of the nastiest welds you've ever seen.

I've repaired suspension parts and hitch parts of class 8 trucks with self self shielding wire that are still in service. The biggest factors I see in weld failures from the use of self shielding wire are inadequate power, inadequate skill, and inadequate cleanliness and with adequate power you can pretty much overcome the other two. Another factor is wire. I've used parair's prostar line, lincoln, victor and a couple others and believe it or not the best I have used so far is the HF .030 flux cored.

https://www.weldingschool.com/articles/uses-and-advantages-of-flux-core-arc-welding/

 

Hey I didn't mean to start anything just provide some basics. You are correct that perhaps I over simplified. Do you know what the actual wire is that you are using? When I it looked up i found this https://m.harborfreight.com/0030-in-e71t-gs-flux-core-welding-wire-200-lb-roll-63496.html?utm_referrer=direct/not provided

It had this e71t-gs specification. I tried to look it up and data is limited and wire with that spec is sold by several different brands for a similar application. The interesting thing was that some companies used it electrode positive and others were electrode negative. Just be sure to double check what is required because they won't be interchangeable. The next thing is that they are single pass only electrodes designed for thin metal. This is something that you look for in flux cored electrodes because they require the dilution zone to work as desired. More passes cause alloy buildup sometimes from the deoxidizers rather than weld deposits. This makes the weld brittle. The technical specs that I found showed that there was no charpy standards that would be required if they were going to be used in a structural project. I'm not saying that they do not make a product that could be used but it is highly unlikely. Welding is a pretty conservative and most engineers are slow to approve short circuit mig (the power levels used in small units) and even tig. Some electrodes like E6010 do have a long history but are being limited do to the fact that they basically have hydrogen enbrittlement built in. I'm not nocking a electrode that has been built to fill a gap but pointing out that it has limitations. A perfect example of another one is aluminum welding rod. I have seen it in print that it will not produce a weld that would be acceptable by any welding code. It has to do with how affective the deoxidizers can be. I'm going to say hazard a guess and say that is probably the issue with low amperage flux core as well. If you look at something like E6010 it uses a paper based coating that burns to provide a carbon monoxide gas shield. There are a lot of things this electrode does well, it is has a fast freeze puddle that let's it be used out of position that is highly desirable for welding thin materials. One of the downsides is the brittle weld deposits. This makes many companies not allow it's used and mandate that thin metal like pipe roots be joined with TIG or Short Circuit MIG.

I hope that clarifies a bit. If I missed any big items let me know I do like to learn.

 

I wasn't trying to start anything either just to clarify it's not just for hobby use.. Yes the link is correct. Out of the wires I mentioned it has the cleanest, smoothest welds of them, the victor being the worst. I didn't use much of the small spool before it just went to the trash can. I will clear this up though, that HF wire is not what I used back when I was doing truck and trailer building. It was years ago in NM and don't remember the brand or numbers other than we used .035. We were also using it in a Miller 250 welder. Mostly used when we had to weld near a fuel tank or something welded with stick would more than likely start a fire on something outside the shop. I'm highly sure there are much much better wires out than that, for a lot of what we do it is good.

 

That's what is great about this forum, so much experience to learn from.

 

You're likely going to have to cut it apart, clean it up and try again. I've had very little luck trying to fix that sort of thing with flux and heat. Maybe someone else knows a way.

 

You can try chiseling it apart. If that doesn't work, I would probably cut the line with a cutoff wheel. If the split disappears only a short distance in, you could forge it out. If it doesn't disappear, continue cutting through.

 

Before you cut or chisel it apart, you might want to grind back the side a bit to see how far the weld fail goes. It may just not be welded up at the very edge and you can grind past it to good welded steel. There is of course that sweet spot of once you’ve ground a certain amount, yeah I guess rip it apart.

 

Is that not just left over from where they did stick?

 

I’m assuming that’s flat on the face of the layers and not the bias. If so, even if that’s not just where it did stick like kuraki said, my guess is you can grind past it.

 

At some point you're going to have to make the decision on when to start over. I'd grind past to see if you can get past this area and re-forge weld. It may be that this is throughout, and you may only find that out when doing the grinding on the blade, but instead of calling it a loss, consider it as learning.

Depends on what the result of the above is. If it's throughout the billet, then it's probably something you did sub-optimally. If this is the only spot, then it's hard for me to say. I've read that occasionally 15N20 from saw blades can have flaws causing blisters during forge welding.
I can't say for sure, but I just had something similar to happen on a billet that was 3 layers of .070 15N20 on either side of a piece of.125" 1095. I'm thinking it was the steel because it only had happened on the outermost 15N20 weld.