Friday, 20 August 2010

RUSTY BIKE


I saw a Build or Bust episode where Joe Magliato finished his frame with rust. He used a welding torch to heat the frame and then wiped it with something, I suspect it was hydrogen peroxide.
(then click on Harley then click on the "pictures of my bike" hotlink (just above the footrests))
I had no available torch or peroxide but I had read this article
....and inherited some mordant solution from my Dad left over from a contract he had to paint a load of galvanized streetlights back in the 60's.

I had a spare MTB frame, forks, stem and a pair of unchromed north road bars all blasted (by Bournes Powder Coaters in Birmingham)
then I painted all the bits with several coats of mordant solution and left them.



Now I needed it to rust and further searching on the net turned up that the trick was to wipe the surface with warm salty water, this done the finish was perfect.


However I should have washed it with distilled water (rainwater would have done) but didn't. The frame began to revert from the dark protective magnetite to fluffy soft red rust, haematite.

By this time I had finished and was riding it. I remembered something else I read and used aluminium foil with the mordant solution to scrub the frame tubes and then wash off the residue with rainwater. That seems to have done the trick, it has lasted weeks and I now have to apply similar treatment to other parts of the frame when time allows.

Decomber 25th 2010 since that time the frame rust has developed in an interesting way. Red rust colonized the frame but then over time flaked off like a scab to reveal the proper finish I sought underneath. A further complication is that where I spaced the front derailleur with 1 mm thick lead, I created an electrochemical cell which has caused the seat tube (only) to continue to corrode in a spectacular fashion. I intend to change the spacer for a plastic one when time permits. I will also paste additional photos.

Other inspiration came my Dad's steel shovel which formed a firm oxide surface even though it's been outside in my garden for over 20 years, chains on kids' swings in playgrounds which never seemed to go red rusty. But for intentional rust, "rust is not a crime" Mike Burroughs' rusty BMW here  really was the tipping point.

Which leads me to a man with a similar name, Mike Burrows, his book Bicycle Design, describes using shorter cranks - down to 120 mm - so I've been using 150 mm steel cranks (taken from a neighbours kid's bike - after he chucked it) and I can confirm they are good fun, although your knees notice the difference.

And I just came across a whole house based on rusty steel (28/05/2011)

I had some favourable comments about the bike, which is interesting as my other bikes are better (more expensive) and conventionally prettier (painted or chromed).

I've created a Flickr page for this and other bikes




The experiment is ended, I dismantled the bike and took it to the tip for recycling. I felt slightly guilty as it was a working bike which rode well and had I the inclination I could have removed the rust, used some of that new-fangled paint and made it good. Sadly I am aware of my mortality and I have a huge number of unfinished tasks, I don't want this so I will have to repress the guilt and move on. Maybe I should rewrite this post in the style of a scientific experiment from school, equipment, method, results, conclusions (another task - see!) but not tonight. More later 07/11/2011

I can say in conclusion that although it was possible to get quite a nice patina, it was difficult to maintain it in a British environment. I can also say that the things that I found most frustrating were the way rust would eat away wherever water was trapped and that parts would weld together. I didn't like the way it spread, rusty water would drip and colonize areas that wouldn't rust on a normal bicycle. Sacrificial corrosion of plated items occurred which meant those parts had to be scrapped when the bicycle was dismantled. Some people reading this may think of COR-TEN steel which doesn't behave like this but it does, if you read the design guides water traps should be designed out and dissimilar metals should be avoided.

Keeping the finish is like balancing a pencil, it's possible but it takes a lot of effort; and I have other things to do. The wheels will be used for another project, they came off a Raleigh MTB.

Although the bike has met its maker a long time ago evidenced here,  http://www.flickr.com/photos/61001946@N06/7573669300/in/photostream  you can go up a level and look at the collection rust in the landscape.

In 2013 the topic still interests me and I came across this article today http://phys.org/news/2013-01-scientists-iron-eating-bacteria-electrons.html the bacteria only respond to electrons of the same frequency, others aren't so tasty perhaps.

It never stops, https://twitter.com/search?q=%23egyptianrust there is a nail varnish called Egyptian Rust. A search on that lead me to http://www.beautytrainingstudio.co.uk/History-Of-Nails.html it was Cleopatra's favourite colour apparently. 05/10/2013

I sent an email to myself back in July 2012, I have just rediscovered it.  The word is pyrophoric and here is the link http://survivaltopics.com/flint-and-steel-what-causes-the-sparks/ it turns out that there is a layer of rust slowing down oxidation but the temperature of the sparks is a factor of the surface area to volume ratio. 01/01/2014.

Since those heady days, I discovered electrolysis to remove rust from iron and steel and have used it extensively restoring lathes and tools.  This album contains some interesting photos. I have noticed that as the steel starts to rust again after treatment it often forms the right type; magnetite. 25/09/2017

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