Safe way to remove rust from masterplate?

jch02140
on 17 Apr 21 (20:46)

Hi,

This is not really related to letterpress…

I have recently acquired a few pieces of Cronite master plates, but some of them have rust all over the plates. I am wondering if there is a safe way to remove the rust without damaging the plates or the letters which are used for engraving?

I have heard of using vinegar/salt with lemon juice, but I am not sure if it will damage the plates. If anyone has any suggestions would be greatly appreciated.

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TollundPress
on 17 Apr 21 (21:38)

Have you considered Evapo-rust? I have used it quite extensively recently on my press (upon the recommendation of Adam Savage from the show Mythbusters) and it is gentle but pretty impressive - but also quite pricey. More info at https://www.theruststore.com/Evapo-Rust-FAQ-W21.aspx

jch02140
on 20 Apr 21 (17:32)

Hi,

Thank you for your reply. I haven’t heard of Evapo-rust yet. Will certainly check it out. Thanks for the link.

If anyone has other suggestions feel free to let me know.

Bruce cpd
on 21 Apr 21 (06:29)

Hi, I remove the rust with waterproof emery paper or fine sandpaper wrapped around a sanding block and a mild solvent or cheap motor oil. If you are going to be using the masterplates for their intended purpose than the surface does not need to be super shiny and the incised lines are deep and bold enough that you won’t damage them with this method. If you keep them dry and use them regularly, wipe them off each time, then they will stay usable. If they get wet or sit unused then rust happens.

If you want to display them or use them for some purpose where you want them shiny you can clean them up and send them to Cronite and have a chrome coating applied to give them a lasting, shiny look. Alternatively you could use a sandpaper block to grain them and spray them with a clear coat.

Do you have a pantograph machine?
Bruce