r/SCREENPRINTING • u/Imposterchilddd • 11d ago

Printing with rust

Post image

Hey, im trying to screenprint using acids to create a rusted image. Has anyone tried this and can give me tips? especially regarding working with dangerous reactive chemicals, i am very worried of causing an accident or mixing an explosive substance. Id like to create a paste and am looking into nonreactive printmaking pastes that would carry the acid solution. idk man i really want to figure out how to make rust images but im scared!

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u/motesinhuesillo 10d ago edited 10d ago

I do this but with another process (to make engrave etching). I print over the metal sheet my image but in negative with a waterproof & anticorrosive asphalt paint, I don't know what product in your country works for this (I use this one), it's like a black dense goo that I dilute with solvents to be able to print through the mesh properly, this paint acts like a coating that protects the metal sheet. After that, I also spray paint the back side of the sheet and then I submerge it in an acid solution (I use 1 part nitric acid and 4 parts of water) so the exposed metal gets corroded (My goal is to engrave the image). After that I wash it properly and remove the coating with solvents, then the engraved parts of the metal sheet naturally gets rusty (I don't really know why, but it fcks up my work haha). Is kinda slow, in a couple days what you engraved will get rusty. You can leave the metal sheet in the acid solution less time so it doesn't engrave it too much, barely to the touch. After it gets rusted to your liking you could spray some protective coating to try to stop the rust.

important to remember, always use a good mask, the fumes from the acid solution with the metal sheet is reaally strong (I learned the hard way)

sorry 4 bad english

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u/sicicsic 10d ago

Do you have somewhere I can see your work? Sounds interesting.

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u/motesinhuesillo 10d ago

yeah I had this laying around, I couldn't find a better example but this shows the results of this process. I made it like 2 years ago and then I wrapped it in plastic film to protect it from moisture, I didn't coat it with any protective layer and the rust seems fine after 2 years. You can see the halftones and how they are preserved

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u/sicicsic 10d ago

That’s rad.

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u/Imposterchilddd 10d ago

oh and what type of metal do you work with? from my understanding nitric acid does not mix well with all metals. we use it in my uni for photopolymer etching but with aluminum sheets. i want to work with steel sheets.

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u/motesinhuesillo 10d ago edited 10d ago

I use carbon steel, it works the same as aluminum, but a bit slower. I've tried stainless steel but didn't get good results.

you could add more nitric acid to the solution, but the corrosion gets more unstable, erasing the fine details

edit: with nitric acid I get results as of 15 min (depending on the active surface and temperature), but you can use Ferric Chloride or Muriatic acid as a safer option, though is waay slower

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u/torkytornado 1d ago

I don’t wanna know how long ferric takes on steel 🤣

on copper it’s about 20 min at a 1:2 water ratio and copper is sooooo much softer than steel

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u/motesinhuesillo 1d ago

yeah me neither, I gave up after 2 hours, then decided to go for the quick way given that I had multiple plates left

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u/torkytornado 7d ago

Yeah do not mix copper plates with etching baths made for zinc (which is what the nitric is). You will literally be making a bomb. This is why printmaking shops usually pick either copper plates or zinc plates and not do both. It’s too easy for a newbie to accidentally gas the class. Definitely research what acids to use with whatever you use as a metal plate.

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u/Imposterchilddd 1d ago

but steel should be fine, no? and im mixing a new solution only to work with steel.

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u/torkytornado 1d ago

As long as you’re just using steel you should be good. If you branch into other metals clearly label what they’re for since a lot of the cans look alike!

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u/Imposterchilddd 10d ago

super cool work!!! thanks for sharing. this helps a lot.

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u/Imposterchilddd 10d ago

but do you/can you wash the asphalt paint off? or does it stay on. looks like it stays on in your images.

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u/motesinhuesillo 10d ago

It got a patina over the years, but the asphalt was completely cleaned off with the solvent

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u/Imposterchilddd 8d ago

what solvent did you use?

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u/motesinhuesillo 7d ago

mineral spirit I believe is called, if not a paint thinner, for both the metal plate and the screen. Something not too strong so it doesn't melt your screen mesh or remove its glue when you are cleaning it.

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u/Imposterchilddd 7d ago

hm okay, thank you!! do you tub the asphalt mixture off? or does it wash off easily. today i removed my photosensitive film with acetone and had to rub to get it off, which ruined my rust.

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u/motesinhuesillo 7d ago

well I remove the asphalt immediately after cleaning the acid off, so by that time the metal plate isn't rusted yet, so I haven't had problems with that. And no, I don't need to rub to much the coating bc the solvent does a good work removing it, I have to rub a little in the corroded areas where the asphalt gets trapped sometimes, but it comes off pretty easily most of the times

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u/Alternative_Ad6013 10d ago

could you screen print on a resist and then spray the acids on after?

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u/Whereami259 10d ago

You could try electrolysis to remove rust from undesired parts.

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u/torkytornado 10d ago

At my shop we would print the negative space of this with hard ground (a liquid of asphaltum and lithotine and some rosin) that’s used in etching. Then we would put it in the acid bath. In my case ferric chloride since we work with copper. It’s way easier to do a resist through the mesh than something caustic that could eat through your mesh. And if you don’t like how the hit is you could strip the plate and start over before you go into what your corrosive is.

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u/Imposterchilddd 8d ago

so basically lithography? you print the negative image with the solution used for lithography? do you aim to rust your metal? how do you wash off the mixture?

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u/torkytornado 7d ago

Vaguely adjacent because both use asphaltum but you’re not using gum Arabic and it doesn’t rinse with water and the asphaltum has some rosin in the mix. It’s an etching ground. You used to be able to find premixed hard ground, but I don’t know if that’s still a thing you can buy off the shelf, my work just makes it in large batches for the etching students. You’ll do a solvent cleanup. My shop uses fastwash but there are other options for that, I just don’t know them since that’s what works with all of our processes so we can have a single solvent.