A few weeks ago I had the run of the house while my husband and daughter were out of town, so I conducted a science experiment that involved dunking a very rusty typewriter in a citric acid bath.
The experiment wasn’t a failure, but my outcomes were different from my expectations – and that’s not a completely bad thing. This is an ABC Afterschool Special where everybody learns something from a challenging experience and grows a bit.
Following a 7th grade science fair outline, I describe my experimental process below:
I dunked a solidly rusted 1929 Royal 10 into a 10% citric acid solution in an effort to remove rust. The goal was to either a) make the typewriter functional or b) render it a usable parts machine for another Royal 10 project I have. **SPOILER ALERT** While the citric acid solution effectively removed rust, it did not produce a functional typewriter.
I bought a 1929 Royal 10. It was completely rusted but intact with the exception of missing carriage ball bearings and pinions. I thought, yeah, I can make that work. The machine had apparently spent much time in a damp environment, as it was an immobile, solid block of rust. It was so rusted, I couldn’t remove the ribbon spools.
Despite liberal application of penetrating lubricants, nothing was moving. I have worked with rusty machines before, and usually after a few days of lubricants and gentle urging, the machine will move. This one didn’t. Not a thing moved. I couldn’t even remove the screws or cover plates. I finally was able to remove the ribbon spools using some naval jelly, but it was a struggle. Those special Royal ribbon spools are expensive, so that’s a win.
Here it is on my work bench. It doesn’t look bad in this picture, but it was so, so solid.
Materials and Methods
I read an interesting forum post about a citric acid dunk for a rusted typewriter, and became intrigued. Maybe, maybe I could get this thing moving.
Here’s what I used:
- Simple Green
- Big plastic tub
- A collection of brushes in different shapes and sizes
- Plenty of rags
- Drop cloth (old curtain)
- 5 lb bag of citric acid powder
- Baking soda
- Air compressor
- PB Blaster
The very first thing I did was remove the carriage. I did not want to dunk the platen since it has a wooden core that would swell and split. I did a dry brush with my bottle brushes and brass bristle brushes to loosen junk that my lubricants loosened. I then placed the typewriter in my huge plastic tub and blew out loose debris with my air compressor.
I then hauled the typewriter up to the upstairs bathroom to de-grease it prior to its citric acid bath. Wrapping the keys in plastic wrap to keep them dry, I dunked the typewriter into a solution of Simple Green and water to de-grease the typewriter since it was full of lubricants. Then I scrubbed the heck out of the typewriter.
This is something I have always dreamed about: scrubbing a dirty typewriter like a pig going to the state fair, but it was, in reality, really gross. The typewriter was slippery and awkward and left a nasty brownish ring in the tub. I felt a wave of irritated exhaustion wash over me, but I knew I had to complete the mission. After some therapeutic swearing, I rinsed the typewriter and dragged all 30+ slippery pounds of it back downstairs to the garage. I was already so very tired.
I had bought a 5lb bag of 100% citric acid powder online (it was about $11.00). I liked the idea of using something fairly safe (citric acid is used in canning and soap making). In my big plastic tub, I mixed up an approximate 10% solution by mixing the 5 lb bag of citric acid (about 2268 grams) and about 6 gallons of very hot water (about 22.7 kilograms). I converted everything to metric to make my calculations simpler. If my math is wrong here, let me know in the comments.
After I filled my tub, I gently lowered my typewriter into the solution. The level was not high enough to completely submerge the typewriter; and I wanted the level to be just shy of the keys, so I filled buckets with clean water and placed them in the tub to raise the level of the solution.
Every couple hours I would check on the typewriter in the bath, giving it a good scrub and testing parts for movement. The typewriter soaked for a total of 36 hours. I then removed it from the bath, added fresh water and a box of baking soda to neutralize the acid. I rinsed it off, blew out the water with the air compressor and sprayed the dry typewriter liberally with PB Blaster to prevent flash rust.
After a couple hours of the citric acid soak, I was able to remove a spool cover plate. The frozen mainspring began to move. Keys began to move. I got very excited. And waited. I really wanted the escapement and tab mechanism to start moving. After 36 hours I gave up and removed the typewriter from the citric acid solution.
Look how fresh and clean that thing is. This citric acid solution effectively removes rust. However, the escapement and tabbing mechanism still don’t move.
But, I was now able to remove previously immobile screws and pins, and I started to slowly dismantle the typewriter for the parts I needed for its 1925 Royal 10 brother.
The extended soak had caused the paint was to soften and flake in places. At least one spring disintegrated.
I ended up with about six gallons of left-over citric acid solution. I don’t think all the hydrogen ions (?) were used up in the chemical reaction so the solution still works as a de-ruster. I dunked some other rusty parts in the left-over solution and it removed rust.
This guy explains the chemical reaction (starting at about 7:30 in the video). To me, his wonderful voice adds credibility to his description of the chemical reaction.
My expectation was that the major mechanics of the typewriter would be freed after the citric acid dunk, and I would be able to make the typewriter functional. That didn’t happen, but I ended up with a good source of Royal 10 parts. Still, I was a bit disappointed. I will definitely use citric acid as a de-ruster (heck, I’ve got six gallons of it), but I probably won’t do the total dunk again.
Also, I shouldn’t have dunked it for 36 hours. The gentle acid slowly ate through paint and at least one small spring, and the extended soak didn’t improve the mobility of the escapement and the tabbing mechanism.
In addition, I learned these things:
- Like murder, dunking a 1920s standard typewriter is a dirty business and everyone and everything associated with it will be sullied. And like murder, there were many dark-night-of-the-soul moments of “What have I done?” I am very glad there were no witnesses to this. The clean-up was interminable, but I left no evidence as to what had transpired.
- 1920s standard typewriters seem to gain hundreds of pounds in awkward, slippery weight during the dunking procedure.
- Rust never sleeps and flash rust is a real thing. You need to dry that thing after the dunk and grease it up all over.
I was fortunate in finally being able to remove screws and pieces from the formerly rusted typewriter. This typewriter is slowly dying so that its brother, the 1925 Royal 10, might live. Thus far, it has given up:
- four good feet
- two glass side windows
- numerous screws
- two carriage clamps
- a key lever connector
- a margin release button
- platen (getting there – I need to address rusty set screws for removal first)
I was able to donate a right carriage knob to another typospherian in need of a Royal 10 knob. If anyone needs a Royal 10 part, let me know. I would like to use all parts of the buffalo.
What I really need to remove is the type bar guide so it may replace the broken guide on its 1925 Royal 10 brother. After de-rusting, I was able to finally take out its mounting screws, but the guide remains firmly in place. Does anyone out there have experience removing a Royal 10 type bar guide? Do you just pry it off the pins? Is it secured in another hidden location?
Finding Your Fun
My verdict on the whole experience is that I thought this would be fun, and it wasn’t. It was a lot of gritty, filthy work and slippery heavy-lifting, and though I have a really good parts machine now, it didn’t result in a functional typewriter.
To work through my mild disappointment at this and to find my inner fun, I turned to the curative power of my club music playlist that’s packed with Kylie, J Lo, Robyn, Gaga and robots. My secret shame is dance music, and this playlist transports me. Some people meditate or do yoga or drink, but me, I listen to my Girls + Robots playlist. When I listen to it, I am not eating a banana and doing laundry, I am out clubbing with my Party People. I am alive to the beat:
I really, really need to replace that broken type bar guide.