Does Weld Prep Really Matter MIG Welding Over Mill Scale Tested

CREATIVE EDUCATION

#DJViral2025 #LaguTikTok2025 #DJRemixTikTok #LaguViralTikTok #KompilasiDJ #DJRemixViral #LaguDJTikTok #TikTokDJ #RemixTikTok2025 #DJIndonesia #DJViral #TikTokHits2025 #DJGoyang #LaguEnakBanget #RemixTerbaru #DJFullBass #DJTikTokHits #LaguSedihRemix #TikTokVibes #DJGalau #AutoGoyang #FYP #LaguFYP2025 #TikTokTrending #LaguSedihTikTok #MusikViral #DJSlowTikTok #EmotionalDJ #DJMix2025 #LaguTiktokGalau #DJSantai #DJBreakbeat #MusikTikTokViral #RemixIndonesia #LaguTikTokTerbaru #DJPopuler2025 #LaguTiktokRemix #FullRemixDJ #MusikGoyang

Transcript

00:00Do you really need to remove your mill scale before you run a weld or can you just run right

00:09over it? What kind of impact does that have? We're going to dive into that today. We're going to do

00:13a bunch of tests at different levels of settings and see how the welds actually turn out. I recently

00:20did a video showing the limitations when you're running a welding machine that just plugs into

00:25120 volts. In that video, I ran a few of the tests on some quarter inch plate that still had mill scale

00:31and I got a lot of comments saying that isn't a best practice. Now, I brought this up in the video

00:36several times that I did that on purpose because I wanted to look at the worst case condition if you

00:42have mill scale and you're limited on power and I want to test mill scale versus no mill scale with

00:50lower settings like what you'd have on maybe 120 volt machine or maybe just a bit above that

00:55and then on some hotter settings that are still short circuit MIG but running a little bit larger

01:02diameter wire and a little bit hotter. Now, my favorite tool to remove the mill scale are these

01:08purple strip discs. I'll put a link down in the description for them but I like them better than

01:12a grinding wheel because they don't dig into your material. There are some other specialized mill scale

01:17discs that you can check out but these are pretty cheap on Amazon and they work pretty well for me.

01:22So, I've got some bright shiny metal here on half of the coupons and so I'm going to have two that have

01:28mill scale and two that don't to run different settings with them. Now, I'm going to set the

01:33machine here to 350 inches per minute which is going to give me about 120 amps and I'll leave it right

01:40at the recommended 19 volts for this and then because this is a little bit lower amperage than

01:47I'd have ideally I'm going to be able to move pretty slowly and I'm going to use a little bit of

01:53manipulation but notice I never leave the puddle. When you see you know more of the MIG-like TIG stack

01:59of dimes manipulation that's kind of moving your puddle around. This is just spreading the puddle out and

02:05helping me to keep my pace and in the end I got a pretty good result. It looks a little bit cold

02:12because the settings are but overall not too bad. Now, let's try the exact same thing at least to my

02:18best ability to replicate it here without any mill scale. So, with the mill scale removed I'll use the

02:26same basic technique. Notice I'm doing just that little bit of manipulation and I'm moving pretty slowly

02:32to allow that material, the filler metal, and the heat to accumulate. Now, notice I am getting a little

02:38bit of spatter here. That's largely because I'm running kind of the higher end of amperage for this

02:44little O3O wire. You can run it quite a bit higher but when you get beyond this you start to get more

02:49and more spatter and notice it's stuck to the material a little better but I think it'd chip off

02:54just fine. So, the weld bead profile is pretty similar for both of those I'd say. I'm going to switch

03:00machines over to the MIG 2800. I just got this machine in to do a series on welding thicker

03:06material with higher amperage. This is an example of running spray transfer. I'm also going to be

03:10looking at dual shield flux core and some other processes like that over the coming weeks so

03:15stay tuned for that. Now, spray transfer like that when you're welding on thicker metal that's going to

03:20be a great way to go but today I'm going to turn this down a little bit just to keep running short

03:24circuit MIG only with some higher settings. That way we aren't really introducing another variable

03:29so I'm looking for that bacon frying sound like we had before just a bit hotter with a little bit

03:34bigger wire. So, here when I started my weld if you do the math I should be somewhere around 200 or so

03:42amps with these settings. Now, my voltage is a little bit higher than I'd like so I need either a little

03:48bit less voltage a little bit more wire speed to run ideally but since I only tacked up the four coupons

03:53I'm just going to roll with it. It's not totally out of the question. It's just a little bit more spatter

03:57than I would normally like but it's still pretty clean not bad so I'm going to run the same settings

04:04here and the same technique just a very very slight oscillation here and this one is without mill scale

04:12so we'll have one with and without mill scale on both the low and high settings that we can go ahead

04:18and test. Once again, not too bad a bead profile there. Now, I'm going to test these welds in two

04:24different ways. I'm going to cut one inch off of each end and then polish it a little bit and etch

04:31it and then I'm going to take that middle section and break it open from the root so that we can see

04:37along the entire length how well it penetrated and get a better overall picture. So, I'm just using my

04:43port-a-band to split these open. You know cutting through these welds on here is really hard on the

04:49blades but after that I true everything up here on my belt grinder and then polish it just a little

04:55bit with a scotch-brite pad and that seems to be enough generally speaking. So, I have my layout here.

05:00Now, I'm just going to use a little bit of etchant here to try to reveal the weld nugget the best I can

05:05and then break that center section open. I really need a better way to do this. I get a little nervous

05:09when I'm running these but the point is to open them up and I just wanted to point out here just how strong

05:17these welds are. I mean, even after it's broken along the whole length of the weld, look at what

05:23it takes to get it all the way apart. Now, if you're doing this on your own, you don't necessarily need

05:27it to be broken all the way apart. I just did it to be able to get a better look. Alright, let's go

05:32ahead and take a look at the results here. So, this is the colder settings with mill scale. Now, if we look

05:38at the overall profile of the weld bead, I would like to see this approach, the toe of the weld

05:46approach at a little shallower angle. Right here, it's getting close to that 90 degree mark but it

05:51isn't quite there. And you can see there is some amount of penetration into the material and down

05:57to the root but not really past it. Alright, let's go ahead and take a look at the brake test results.

06:02Now, the fact that this broke open doesn't mean that it failed. What you're looking for here is along

06:09the whole length of the weld, did it consume the actual root? And I would say that no, it didn't

06:16here in this case. If you look, you can still see the original edge. It's a nice straight line. So,

06:23it would have been nice to see more penetration. That being said, it did hold fairly well and the

06:30breakage is all in the middle of the weld joint on both sides. So, you certainly have, you know,

06:38some people talk about if the conditions aren't ideal, it's just like weak as water. It's actually

06:43still a pretty strong weld but definitely not best practice there. Now, these are the same settings,

06:51those colder settings with the mill scale removed. Notice the toe of the weld is tied in much better.

06:57This angle where the toe approaches the base metal is much more shallow. So, that's a good thing. That

07:03might have partially been variations in my technique but I'm sure the removal of the mill scale helped.

07:09There's no undercut and there wasn't in the other case either. That can be an issue with mill scale

07:14is it can lead to undercut but it did penetrate into the base material if you follow that line down

07:20in both cases but not much into the root. You could see just a little bit of a gap right there at the root.

07:29So, notice on the brake test, once again, it's a pretty straight line across here. Right there,

07:35you're getting down into the root right there in a few locations but generally speaking, you're not

07:41getting in there very deep along the length of the joint. It did break in the weld material right

07:47here. You can see that it penetrated through and you have some delamination on the top side and then

07:53again on the bottom side but still, you know, potentially a little bit of lack of fusion

08:00running these colder settings. Again, this is running about 120 amps or so on this quarter inch

08:06thick material with O3O wire. So, definitely colder than it needed to be and so that's a struggle with

08:14or without mill scale but, you know, removing the mill scale definitely did help it run better.

08:20Alright, so if we take a look here, these are the hotter settings with mill scale and the weld bead

08:25profile is much better. Now, the cross section I ended up with over here, it's piled up a little

08:30bit which isn't ideal but that's more of a technique issue than a process issue and we're looking at the

08:36process here. So, right here you can see more penetration down into the plate and past that root

08:44a little bit. So, same thing over here, we got much better penetration. So, those hotter settings

08:51still, you know, could be hotter than that honestly on this quarter inch thick plate if you went to 0.45

08:58wire or ran like a spray transfer or something like that but you're definitely penetrating a lot better

09:03in past that mill scale. Now, let's take a look at the brake test and notice along here it's jagged all

09:10the way. So, you don't have a straight line. That's what I like to see on a fillet weld brake test because

09:16that means that it penetrated down into the root along the whole length of the joint where it failed.

09:22Now, if you look at the failure up here, it's pretty deep into the base material there more of

09:30like a delamination. However, on the bottom you can see right here it's just flat in a few areas. You

09:38have kind of a different sheen. And if you look on this bottom side here right through there,

09:42I believe there was a little bit of lack of fusion probably from that mill scale.

09:47So, it did seem to have an impact on the overall weld. So, definitely, you know, reinforces that

09:57concept of removing the mill scale. Here we have the hotter settings with the mill scale removed.

10:01This should be the best case of the bunch. And if you look at it, it is. So, right here,

10:07you can see we got good penetration down into the plate on both sides. And you hit that root

10:14on both sides. Good weld bead profile. And so, definitely what you want to see on those macros.

10:23Now, if we look at the brake test, this is the one that was hanging on for dear life. But look at

10:27that jagged edge all the way along here. You got down into the root throughout. And then you can see

10:35this is pulling from within the material, delaminating that along that grain structure. So,

10:42you definitely have some good sound strength in that weld. I just wanted to point something out

10:48here looking side by side. This is with mill scale and without, both hot settings. So, here with the

10:54mill scale, if you look at this surface, you can see how it has a different appearance than this.

11:01Right here, this is pulling out of that grain structure in the lower plate, down in the base

11:06metal. Where some of this was right in that region, but a lot of this more egg crate style really was

11:14not fused beyond the mill scale. So, even with these hotter settings, the mill scale really had an impact.

11:22All right. So, what's the takeaway from all this? Well, it's no surprise that removing your mill scale is,

11:27you know, beneficial. But I was honestly a little bit surprised of how much effect that it had at the

11:33higher settings. I thought when you're running a bit hotter that you wouldn't really see that lack

11:38of fusion in the fracture surface like we did, but you definitely did. So, even if you are running a bit

11:44harder, it's certainly worth removing the mill scale. Also, it only takes a few seconds to remove. It shows better

11:51craftsmanship and the weld runs better. So, there's really no reason not to take a minute and just

11:57knock that mill scale off. If you enjoyed this or learned something, let me know by hitting that thumbs

12:02up or leaving me a comment below. And if you are just learning to weld, be sure to check out my online

12:07courses. I keep them as affordable as possible and walk you through step-by-step the whole process

12:13so that you can learn faster with hands-on targeted exercises. And you'll be up and going,

12:19building stuff that you've always wanted to. Thanks a ton for tuning in. We'll see you next time.

Category

Transcript

Be the first to comment

Recommended