Probably the most boring Cerbera video ever
Discussion
Decided to run a little chemistry experiment and try and remove the rust from my suspension components using electrolysis. Ignore the chickens, I woke them up and they came to watch.
See here: http://vimeo.com/21408931
You may ask why not just shot blast them? I wanted to do it myself; non aggressive process; cheap; fun etc, etc.
There is a real danger this video might send you to sleep.
See here: http://vimeo.com/21408931
You may ask why not just shot blast them? I wanted to do it myself; non aggressive process; cheap; fun etc, etc.
There is a real danger this video might send you to sleep.
Very good sir,think my bits will be done like that thankyou for the information.Should work on brake discs. In fact I'll try that next. The process works by line-of-sight so the electrode needs to be able to 'see' the rust. Thus, I'm modifying the tank to include electrode plates on the base and all four sides of the tank so they can 'see' all sides of the workpiece at once. I'll video this when done.
The power supply I used is here: http://www.maplin.co.uk/1-20v-0-5a-slim-bench-powe...
I bought it to do electroplating but to works fine for this application. If it's too expensive I'm told a cheap 12v battery cherger is OK.
The power supply I used is here: http://www.maplin.co.uk/1-20v-0-5a-slim-bench-powe...
I bought it to do electroplating but to works fine for this application. If it's too expensive I'm told a cheap 12v battery cherger is OK.
You mention in the video that you're planning to coat with a zinc primer and then epoxy.
My chemistry is a bit rusty (excuse the pun), but the zinc will need direct contact to the metal if it is to provide any useful catodic protection, and your electrolysis will leave the surface of the component as Fe3O4 (I think), which is a poor conductor compared to the base steel (thus compromising the protection of the zinc).
When I did my suspension bits (and subsequently the chassis), I considered the issue of zinc priming very closely, and basically decided that it comes down to a trade-off between the catodic protection of the zinc and its resistance to chipping (the zinc undercoat compromises the adhesion of powerdercoating or epoxy-based paints)
On my suspension, I did the front wishbones with an undercoat of Wurth Zinc 300 and several coats of white stonechip paint. The rears I had professional powdercoated. Eighteen months on, both are still looking pretty good, but the fronts have picked up a few spots of rust where the paint has chipped (primarily from where I bashed it in the re-assembly process, but a couple of pea-sized stone-chips too).
The chassis I've had done in epoxy-mastic, with no zinc primer, and there's not a chip anywhere (although it's only been on 6 months).
IMO, the lesson I've learned is that the decision to undercoat with zinc is marginal, so if the cathodic protection is compromised by the elerolysis process, then it's probably a better idea to go with pure epoxy-mastic.
My chemistry is a bit rusty (excuse the pun), but the zinc will need direct contact to the metal if it is to provide any useful catodic protection, and your electrolysis will leave the surface of the component as Fe3O4 (I think), which is a poor conductor compared to the base steel (thus compromising the protection of the zinc).
When I did my suspension bits (and subsequently the chassis), I considered the issue of zinc priming very closely, and basically decided that it comes down to a trade-off between the catodic protection of the zinc and its resistance to chipping (the zinc undercoat compromises the adhesion of powerdercoating or epoxy-based paints)
On my suspension, I did the front wishbones with an undercoat of Wurth Zinc 300 and several coats of white stonechip paint. The rears I had professional powdercoated. Eighteen months on, both are still looking pretty good, but the fronts have picked up a few spots of rust where the paint has chipped (primarily from where I bashed it in the re-assembly process, but a couple of pea-sized stone-chips too).
The chassis I've had done in epoxy-mastic, with no zinc primer, and there's not a chip anywhere (although it's only been on 6 months).
IMO, the lesson I've learned is that the decision to undercoat with zinc is marginal, so if the cathodic protection is compromised by the elerolysis process, then it's probably a better idea to go with pure epoxy-mastic.
Regarding the zinc, my plan is slightly diffent. The parts will now go into a home made tumble polisher to give me a bare steel with a satin finish. From there they will be hot zinc sprayed. In this process zinc wire is fed into a flame and sprayed onto the steel in molten form. I'm told the rough surface of this metalic layer provides a good key for the twin pack.
Then again, having not done any of this before, it could all go wrong. Fingers crossed. If people are interested, I'm happy to keep filming.
The next step is to make the tumbler using an old industrial mango chutney barrel and wheelchair motor. The things I do for this car!
Then again, having not done any of this before, it could all go wrong. Fingers crossed. If people are interested, I'm happy to keep filming.
The next step is to make the tumbler using an old industrial mango chutney barrel and wheelchair motor. The things I do for this car!
Me too. Very interesting stuff.jonbarrett said:
I'm told the rough surface of this metalic layer provides a good key for the twin pack.
My experience is that there's no problem in the adhesion between the top coat and the zinc, but rather between the zinc and the metal. I used cold zinc, so your hot zinc process might be better, but I found that you can hit the epoxy mastic with a hammer and nothing happens, but if you try the same with the stonechip-coated zinc, then the zinc tends to come away from the metal.Gassing Station | Cerbera | Top of Page | What's New | My Stuff