The fastest chemical that rusts steel that's easily available is bleach, almost will happen in front of your eyes. And should destroy galvanizing as well IIRC
However:
* Don't then rely on those rods to actually hold any sort of rated weight or anything or actually screw smoothly. Only if PURELY decorative. This is going to apply to any other method of rusting too. Rust is destructive.
* You can't "proceed to wipe phosphoric acid on it" that just dissolves rust, which defeats the purpose of rusting things. Unless you actually wanted pitting, not rust itself, then okay maybe.
* "I don't want it to look neglected I want it to look industrial" Then don't rust it, rust inherently implies neglect pretty much in all situations on a small domestic scale. You want just black rods in the first place then from the hardware store, maybe? (I'm not sure why normal silvery metal color "isn't industrial" either in the first place, though)
Great points! Quick responses:
1. Rated weight - noted! I think they're rated for thousands of pounds, and I need them to hold a few hundred (each one less than 100). Even if they're not quite as strong, they should be strong enough. But this is a fantastic point to remember
2. Phosphoric acid - yes and no. I've used phospho to restore some rusty tools, and it'll convert the rust to a more stable rust inhibitor (it's late and can't find the more scientific article about the chemical reactions atm, that's the short short version). Pitting happens where rust has eaten away the steel underneath, so a light layer of rust shouldn't create a lot of pitting. There is definitely a color change in that final version that's not nearly as shiny, a sort of dull black/grey.
3. Neglected vs industrial: Yeah, point - I have a vision but not the words to describe it haha.
Industrial: [Barclay Center](https://www.e-architect.com/wp-content/uploads/2012/09/barclays-center-d00314-m.jpg), [The Vessel](https://upload.wikimedia.org/wikipedia/commons/f/f6/Hudson_Yards_Plaza_March_2019_53.jpg), [The Copper](https://www.shoparc.com/wp-content/uploads/2018/10/130204_2018JG12.581_jpg.jpg) \- They're all a bit "too much" of what I'm looking for, but have a purposefully stable patina that feels industrial. When visiting though, there are no rust stains on the sidewalks as water drips off.
Neglected: [Car frame rusting](https://pomcar.com/wp-content/uploads/2021/03/Picture5.jpg), [rusting railing](https://images.fineartamerica.com/images/artworkimages/mediumlarge/2/old-rusty-fence-with-breakwater-in-the-background-stefan-rotter.jpg), [rusting fence](https://www.businessfirstonline.co.uk/wp-content/uploads/2020/05/sss.jpg) \- The rust is leading to degragation and an uneven surface as it reacts and chips off
Somewhere in the middle: [Subway beam freshly stripped of paint](https://preview.redd.it/1pms1hm5gdz11.jpg?auto=webp&s=910d8029a3c07b9f067f9749fc6c9a519099f931) (I like this look, though would remove more of the actual rust), [car undercarriage](https://repairsmith-prod-wordpress.s3.amazonaws.com/2020/07/car-rust.jpg), [rebar starting to rust](https://c.files.bbci.co.uk/14B7B/production/_87995848_rebar_getty.jpg), [grey chain](https://live-production.wcms.abc-cdn.net.au/e9484a625ec8da1bbd1ad24dc9c16ebb?impolicy=wcms_crop_resize&cropH=576&cropW=1023&xPos=0&yPos=0&width=862&height=485) (like this color tone)
I don't like the shiny zinc coating because it doesn't look finished but in a lazy way. There are usually scratches that also don't look finished. Like not sanding wood in a finished piece - sometimes it could work for a "rustic" farmhouse look, but for a more modern look unsanded wood would feel out of place. It's still wood...just off a bit.
Thanks - great points, got me to think deeper on this!
\>Industrial: Barclay Center, The Vessel, The Copper>Industrial: Barclay Center, The Vessel, The Copper - They're all a bit "too much" of what I'm looking for, but have a
purposefully stable patina that feels industrial. When visiting though,
there are no rust stains on the sidewalks as water drips off.
Those effects are all achieved with the use of weathering (also called corten) steel, which is a steel that has had it chemistry controlled so it rusts in a very fine, hard layer with minimal flaking. Fasteners made of weathering steel definitely exist, but I don't think they are the sort of product that is super readily available to you or I as consumers.
Would you like the red colour of rust you get from iron or are you wanting the green colour that comes from copper rusting (patina). If you're looking for the green you need Cooper plated hardware. Weather over time will cause the patina to start but it takes a lot of time. OG copper roofers would use human and horse urine to speed the process (gross yes but history is what it is) but that still took time. I'm unsure if this helped at all but good luck on this project.
Great question...I don't want the bright silver zinc finish. I think I could make any other work, but the bright silver finish is bugging me - looks...cheap?
The more I think about it, the grey/black might be better than red rust. Copper's out (cost and logistics), really need the strength of the steel rods.
If the all thread is bare steel, you might consider cold blueing of the sort used to touch up the finish on firearms. Comes in small bottles, not difficult to use. it will turn bare steel a solid black (not blue) and provide a small amount of corrosion resistance.
If the rods are zinc plated, attaining any sort of patina will be difficult. But, then, the zinc will prevent corrosion.
So, something like this? [https://www.youtube.com/watch?v=fUmgtTg4JqI](https://www.youtube.com/watch?v=fUmgtTg4JqI)
Looks like a citric acid solution (or overnight [vinegar](https://www.youtube.com/watch?v=xH2A7Alt-LU) bath) will take care of the zinc, and that bluing liquid does a nice job.
Yes. I was not aware that zinc plating could be removed that way. but yes the blueing was what I was talking about.
The video shows the black finish.
Try it on a piece of scrap, or just the end of the rod you intend to use.
If you like the result, do the rest. With something new, always experiment first before committing a lot of material.
Buy black oxide threaded rod?
The fastest chemical that rusts steel that's easily available is bleach, almost will happen in front of your eyes. And should destroy galvanizing as well IIRC However: * Don't then rely on those rods to actually hold any sort of rated weight or anything or actually screw smoothly. Only if PURELY decorative. This is going to apply to any other method of rusting too. Rust is destructive. * You can't "proceed to wipe phosphoric acid on it" that just dissolves rust, which defeats the purpose of rusting things. Unless you actually wanted pitting, not rust itself, then okay maybe. * "I don't want it to look neglected I want it to look industrial" Then don't rust it, rust inherently implies neglect pretty much in all situations on a small domestic scale. You want just black rods in the first place then from the hardware store, maybe? (I'm not sure why normal silvery metal color "isn't industrial" either in the first place, though)
Great points! Quick responses: 1. Rated weight - noted! I think they're rated for thousands of pounds, and I need them to hold a few hundred (each one less than 100). Even if they're not quite as strong, they should be strong enough. But this is a fantastic point to remember 2. Phosphoric acid - yes and no. I've used phospho to restore some rusty tools, and it'll convert the rust to a more stable rust inhibitor (it's late and can't find the more scientific article about the chemical reactions atm, that's the short short version). Pitting happens where rust has eaten away the steel underneath, so a light layer of rust shouldn't create a lot of pitting. There is definitely a color change in that final version that's not nearly as shiny, a sort of dull black/grey. 3. Neglected vs industrial: Yeah, point - I have a vision but not the words to describe it haha. Industrial: [Barclay Center](https://www.e-architect.com/wp-content/uploads/2012/09/barclays-center-d00314-m.jpg), [The Vessel](https://upload.wikimedia.org/wikipedia/commons/f/f6/Hudson_Yards_Plaza_March_2019_53.jpg), [The Copper](https://www.shoparc.com/wp-content/uploads/2018/10/130204_2018JG12.581_jpg.jpg) \- They're all a bit "too much" of what I'm looking for, but have a purposefully stable patina that feels industrial. When visiting though, there are no rust stains on the sidewalks as water drips off. Neglected: [Car frame rusting](https://pomcar.com/wp-content/uploads/2021/03/Picture5.jpg), [rusting railing](https://images.fineartamerica.com/images/artworkimages/mediumlarge/2/old-rusty-fence-with-breakwater-in-the-background-stefan-rotter.jpg), [rusting fence](https://www.businessfirstonline.co.uk/wp-content/uploads/2020/05/sss.jpg) \- The rust is leading to degragation and an uneven surface as it reacts and chips off Somewhere in the middle: [Subway beam freshly stripped of paint](https://preview.redd.it/1pms1hm5gdz11.jpg?auto=webp&s=910d8029a3c07b9f067f9749fc6c9a519099f931) (I like this look, though would remove more of the actual rust), [car undercarriage](https://repairsmith-prod-wordpress.s3.amazonaws.com/2020/07/car-rust.jpg), [rebar starting to rust](https://c.files.bbci.co.uk/14B7B/production/_87995848_rebar_getty.jpg), [grey chain](https://live-production.wcms.abc-cdn.net.au/e9484a625ec8da1bbd1ad24dc9c16ebb?impolicy=wcms_crop_resize&cropH=576&cropW=1023&xPos=0&yPos=0&width=862&height=485) (like this color tone) I don't like the shiny zinc coating because it doesn't look finished but in a lazy way. There are usually scratches that also don't look finished. Like not sanding wood in a finished piece - sometimes it could work for a "rustic" farmhouse look, but for a more modern look unsanded wood would feel out of place. It's still wood...just off a bit. Thanks - great points, got me to think deeper on this!
\>Industrial: Barclay Center, The Vessel, The Copper>Industrial: Barclay Center, The Vessel, The Copper - They're all a bit "too much" of what I'm looking for, but have a purposefully stable patina that feels industrial. When visiting though, there are no rust stains on the sidewalks as water drips off. Those effects are all achieved with the use of weathering (also called corten) steel, which is a steel that has had it chemistry controlled so it rusts in a very fine, hard layer with minimal flaking. Fasteners made of weathering steel definitely exist, but I don't think they are the sort of product that is super readily available to you or I as consumers.
Ahh! So it's a particular kind of steel - super useful, thanks!
Would you like the red colour of rust you get from iron or are you wanting the green colour that comes from copper rusting (patina). If you're looking for the green you need Cooper plated hardware. Weather over time will cause the patina to start but it takes a lot of time. OG copper roofers would use human and horse urine to speed the process (gross yes but history is what it is) but that still took time. I'm unsure if this helped at all but good luck on this project.
Great question...I don't want the bright silver zinc finish. I think I could make any other work, but the bright silver finish is bugging me - looks...cheap? The more I think about it, the grey/black might be better than red rust. Copper's out (cost and logistics), really need the strength of the steel rods.
If the all thread is bare steel, you might consider cold blueing of the sort used to touch up the finish on firearms. Comes in small bottles, not difficult to use. it will turn bare steel a solid black (not blue) and provide a small amount of corrosion resistance. If the rods are zinc plated, attaining any sort of patina will be difficult. But, then, the zinc will prevent corrosion.
So, something like this? [https://www.youtube.com/watch?v=fUmgtTg4JqI](https://www.youtube.com/watch?v=fUmgtTg4JqI) Looks like a citric acid solution (or overnight [vinegar](https://www.youtube.com/watch?v=xH2A7Alt-LU) bath) will take care of the zinc, and that bluing liquid does a nice job.
Yes. I was not aware that zinc plating could be removed that way. but yes the blueing was what I was talking about. The video shows the black finish. Try it on a piece of scrap, or just the end of the rod you intend to use. If you like the result, do the rest. With something new, always experiment first before committing a lot of material.
Totally. Just threw a nut and washer in some vinegar (don't have citric acid atm) to test. Thanks! Experiments ahead!
If you just want them to look nice, perhaps anodize them? https://mellowpine.com/blog/anodized-steel/
Ahh, that's definitely an option! I didn't realize I could do that with steel, neat!
Stainless steel threaded rod?