Prepping black iron pipe for welding?

New Topic: So after some discussion, it seems like the best solution for my original question about welding casters to some black iron pipe would be to weld some plates to the pipes then mount the casters to those plates. The conversation now is how to best prepare the black iron pipe itself for welding.
Any and all suggestions are welcome!


Archived Question - already answered

Original Post: I took a MIG welding class a few months ago and thought I could apply it to an upcoming project.
I’m building a desk and was going to use black iron pipe as the legs, would I be able to safely weld some of these casters to the black iron pipe?
I’m still very unsure of what metals I can ‘safely’ weld…

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The specs don’t say if it’s galvanized or not (usually these are), if it is, don’t weld it.

I’d suggest that you’ll probably have better results (and be able to replace the wheels in the future if you need to) by welding a small piece of plate to your pipe, then bolting the casters to the plate.


Ah that’s a very good idea!
So welding black iron pipe is safe?

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Yeah, the steel is usually a53, no problem there.

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Awesome, thanks for the info! :slight_smile:


Only thing to mention is that the steel must be shiny/clean within an inch or so of the weld. You don’t want to weld over the black coating on the pipe.

Finding a caster that isn’t galvanized is going to be your problem.

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Sorta. Welding in itself does but off some gases. It’s best to clean the black coating off the pipe before welding. A wire wheel or flap disc will take that off. As long as you are not welding galvanized pipe, its ok.

Edit I’d also second Brads suggestion of making a plate for the casters to bolt to.


From the research I’ve done, it looks like some acetone and elbow grease can get the black coating off as well, is that correct?
I was going to have to do that anyway, I wanted to spray paint the final hardware a different color.

I think I’m going to take Brad’s suggestion and weld a small plate to the pipe that the casters will bolt into.

But I was already planning on stripping off the black coating with some acetone, I was going to paint the final hardware a different color anyway.

I think you will need to grind that coating off, the acetone for cleaning / degreasing.

This is right. A wire brush or a flap-disk will both work pretty well.

And once you’ve done so, flash rust is a distinct possibility. Be prepared to prime immediately once stripped to bare metal. Like within 10 minutes in Dallas summer humidity.

Consider just roughing up the varnish with 220 grit sandpaper, cleaning, and priming/painting over.

I hate being the voice of reason but why not drill a piece of plate to bolt the casters to? then weld the plate to the end of the pipe? If a caster fails it can be replaced. I am pretty sure the surface you want to weld to is a surface for the castor bearings and getting them hot or distorted with a weld could very possibly result in premature failure of the bearing. Lots of casters have bearings with nylon cages holding them in place. Just thought I would throw that out there.

There’s an echo in here! :smile:


Additionally if you are not good at cad, you can use the library on the Dynatorch.

I am sorry, I admit that I did not read all 13 posts, they all seemed to be heading down the same trail. You have restored my faith in humanity. If I go back and read all 13 will I find a reason why this idea was dismissed?

Doesn’t seem like it has, OP seemed on board. Most of the rest has been advice on the dreaded “black” coating and how to abate.

movin along here folks, nothin to see here.

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Your post does not appear on my screen was it a PM to the OP?? I just realized you are talking about buffing the black off the black iron?? I have always understood the black to be Iron oxide and would not wash off with acetone or any other solvent but I could have been misinformed. I have welded black iron a few times and have never experienced and off gassing even with MIG

The issue moved from “welding the caster to the black pipe” to “welding a plate to the black pipe” but the other issues (re: pipe coatings) didn’t change, so then conversation topic didn’t really change either.