VIDEO: Tools for Cleaning Mild Steel
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Jan 25, 2024
VIDEO: Tools for Cleaning Mild Steel
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0:00
In this video, I want to explain to you how I clean metal for the best possible MIG welds
0:07
Now as I've mentioned before in other videos, strictly speaking, you don't need to get back to bare metal in order for a MIG weld to work
0:15
But for it to work to its full potential and for the bead to look as nice as possible and be as strong as possible
0:21
you do need to get back to bare metal. This is a piece of black iron pipe
0:26
It's called black iron because it's black on the surface, although the actual metal
0:32
isn't really black. What you're seeing on the surface here is something called mill scale
0:38
So you can imagine this started off as molten steel and it was
0:45
extruded. Actually, this is a this is welded pipe. I don't know if you can see that, but there's a there's a weld bead in there
0:52
So it actually started off as some flat stock and it was it was bent in a factory and and welded and seamlessly welded
0:58
You can't really see the weld on this side. But during that process of heating and forming and
1:05
manufacturing, there's a kind of with a mill scale forms on the surface. It's a product of
1:12
oxygen and I guess manufacturing oils and pressures and all kinds of things and that's why this is black
1:19
Now it's starting to rust a little bit here too because it's been outside. Bottom line is that we want fresh clean steel if we can for the best possible welds and
1:31
the usual tool for that is something like this. An angle grinder with what's called a flap wheel, which is an abrasive
1:40
It removes a fair amount of metal. It does it fairly quickly in most cases
1:46
but it's not the best for this sort of thing because it actually travels so quickly like this. The maximum rpm on this disk is over 12,000
1:54
I think it probably spins at a full 10,000. I don't know if it says anywhere here
2:01
Yes, sorry 8,500. So it's really spinning very quickly and so quickly in fact that it can actually burnish the surface of the metal and
2:11
not remove the mill scale as fast as you might like or as you can
2:16
What I have found works better than that and it's nicer to use too
2:21
It's more controllable and it's more effective and that's a regular woodworking
2:26
sander. This is a five inch random orbit sander. As I said, it's meant for working with wood
2:31
but it happens to do a great job getting off this mill scale. So I'm going to show you that but before I do I just want to point out a
2:40
couple of different abrasives. This is the sort of abrasive disc that's sold most commonly for use on a five inch random orbit sander. Works great on
2:50
wood and it works pretty good on metal too, but what works better on metal is
2:56
this mesh style abrasive. So you can see my fingers through it I think and
3:02
the advantage there is that there's, well the advantage for woodworking is
3:07
that there's all kinds of holes in here and sanders like this have a built-in vacuum system, a little vacuum system. These holes
3:15
suck the dust in, trap it in this canister. So something like this
3:22
maximizes the the airflow and the sawdust pickup when you're dealing with wood
3:28
But what I have found with metal is that the open weave clogs up less. The abrasive lasts longer, quite a bit longer, than regular sandpaper type abrasives and
3:39
it just does a great job. There's probably different companies that make this kind of thing. This is made by Diablo
3:47
This grit is actually a little fine. 180 is a bit fine for what I'm doing here. 80 grit would be better
3:53
But anyway, let's let's take a look and I'll show you how it works and what clean steel really looks like
4:24
Now that is bare metal and you can see where the sander kind of worked through the mill scale
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This isn't as big of a job as you might think because you really only need to do it where you're going to actually do
4:45
the welding. You know, later on subsequent steps might involve cleaning the whole thing that you've made and applying some kind of paint
4:54
But as far as cleaning metal for welding goes, that's the ticket. It's perfectly clean and you'll get really good results if you try to weld to that
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