Jaeger_S2k
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OJCar
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julianf
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I have wondered before -
A car is stationary for the majority of its life. If you could plug it in such as it was the cathode at all times, the electronegativity would stop rust forming.
If course sacrificial anodes on the sides of ships are the same but then you have fluid. I reckon, even with rubber tires, parking on a steel plate anode would give connectivity when you most need it (like when it's raining)
A car is stationary for the majority of its life. If you could plug it in such as it was the cathode at all times, the electronegativity would stop rust forming.
If course sacrificial anodes on the sides of ships are the same but then you have fluid. I reckon, even with rubber tires, parking on a steel plate anode would give connectivity when you most need it (like when it's raining)
Jelly_Sheffield
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It's only really in the context of continuously spraying it that it's worth considering.
Think about how much quicker clothes dry on the line on a overcast windy day, compared to a very still sunny one.
julianf
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Your cloths maybe loose 2ltrs of water when they dry?
On a 1mtr square tray, that would result in a 2mm drop in level!
Say your losses are 10x as much. 2cm.
Even at 100x as much, 20cm.
Still well within the scope of not worrying about it and getting the hose out once per day, and not constructing some sort of tent!
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Jelly_Sheffield
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I would think 2kg of water was about right for a pair of jeans after a spin cycle, more like 4kg from a hand wash.
But you're taking the comparison too directly there, a continuous spray of droplets has a surface area many orders of magnitude higher than a pair of jeans (or the free surface of a 1m² tub) so the evaporative losses would potentially get much greater.
I would also think that in the average garage or workshop, controlling where that evaporated water goes to might be more important than where it's coming from.
I would say that's a totally valid solution, as long as you're doing it, but it depends if you want to just leave it alone with zero intervention or not, and for how long.
The main thing is that if you set up a continuous evaporust sprayer under a car, you would need to pay some attention to the loss of water so it doesn't just dry out prematurely...
Jelly_Sheffield
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I really want to see a clueless vanlife youtuber use that to waxoyl their vehicle now...
bigegg
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In my initial thoughts, I was considering a "tent" over the car whilst spraying; to constrain the over-spray from missing the tray - rather than evaporation - as I considered that a bigger loss risk.
marlinspike
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Here's my results using the same formula - 1 litre water, 100g citric, 30g soda crystals. I used warm water to mix it which resulted in this when I added the soda crystals.
I forgot to take a decent Before photo so I had to fish the control arm out to take one.
Very heavily corroded as you can see.
Here is the After photo. This is around 3 full days in the solution.
Pretty decent results. I forgot about flash rusting and fished the bits out of the solution and left them to dry in the garden over night, which wasn't a good idea. The black bits are some sort of underseal which has now softened and will probably scrape off. Before I couldn't get the bolts undone but now I can.
So overall, better than just citric I'd say.
Cost was 5kg of citric acid from ebay at £17 delivered and packet of soap flakes from Asda at about £2. Squirt of washing up liquid was free
I used about 2.5kg of citric and a lot of the soap, so total amount was about a tenner. I did some brake calipers in there too but needed a big box of solution for the control arms. There's probably some life left in the solution but it's pretty dark and murky now.
When I was reading up on this I found a forum where someone had had success with soaking a cloth in the solution and wrapping round car body sections. I could see that working with something like an old towel or those big Costco microfiber cloths.
I forgot to take a decent Before photo so I had to fish the control arm out to take one.
Very heavily corroded as you can see.
Here is the After photo. This is around 3 full days in the solution.
Pretty decent results. I forgot about flash rusting and fished the bits out of the solution and left them to dry in the garden over night, which wasn't a good idea. The black bits are some sort of underseal which has now softened and will probably scrape off. Before I couldn't get the bolts undone but now I can.
So overall, better than just citric I'd say.
Cost was 5kg of citric acid from ebay at £17 delivered and packet of soap flakes from Asda at about £2. Squirt of washing up liquid was free
I used about 2.5kg of citric and a lot of the soap, so total amount was about a tenner. I did some brake calipers in there too but needed a big box of solution for the control arms. There's probably some life left in the solution but it's pretty dark and murky now.
When I was reading up on this I found a forum where someone had had success with soaking a cloth in the solution and wrapping round car body sections. I could see that working with something like an old towel or those big Costco microfiber cloths.
Screwdriver
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2.5kg of citric! I'm surprised there's any aluminium left. That's a very strong concentration assuming a receptacle around the size of the part.
200 - 400g would be overkill...
Having said that, the process does require a constant supply of free electrons to reduce the oxide. The upshot being, I am skeptical about the idea of a "mist" or light coating of <whatever> because the process typically requires a large volume of product in order to allow a decent volume of electrons to do their thing. A thin mist of citric for example would become neutralised before it did anything other than reduce thin surface layer. I mean, atomically thin...
200 - 400g would be overkill...
Having said that, the process does require a constant supply of free electrons to reduce the oxide. The upshot being, I am skeptical about the idea of a "mist" or light coating of <whatever> because the process typically requires a large volume of product in order to allow a decent volume of electrons to do their thing. A thin mist of citric for example would become neutralised before it did anything other than reduce thin surface layer. I mean, atomically thin...
marlinspike
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I was using the recipe given earlier so it's whatever ratio that was. They are automotive suspension control arms so it's not aluminium. I don't think you can do aluminium in citric acid for any length of time.
What are the bush housings made of?
marlinspike
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No idea. Perhaps they are aluminium but they are entirely covered in thick black underseal and seem undamaged by being in the solution. These are not the control arms from the car, they're ones I got cheap with a job lot of spares in ebay, so I do have the ones still on the car for spare bits if necessary.
Misterg
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I can't see it's terribly critical, but just to avoid any misinformation, the original recipe was 40g of washing soda (=sodium carbonate), or 30g of caustic soda (=sodium hydroxide).
Nice result. I think in another day or so, the rust in the deep pits will be gone, too.
Most of the citric acid in the solution has been neutralised, so it is nowhere near as aggressive as neat citric acid would be. It's the citrate ions that do the work on the rust, rather than the acid.
pH of citric acid solution is ~1
pH of this recipe is ~ 4
(Not that I'd be confident to leave aluminium in it!)
If you haven't watched the original video, I'd encourage you to do so. He goes through several tests in a very scientific and methodical manner - not at all what I expected from a 'Merican on yoo-choob.
DennisCA
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I've tested this and it works. I also found out you can add baking soda or similar until the pH is neutral or even slightly alkaline. It will still work. I tested using pH sticks.
It also works using lye or washing soda.
I've read elsewhere that if you add Sodium dithionite (also known as Sodium hydrosulfite) it will make the reaction even more effective. 30 grams per liter.
It is short lived, only a couple of days or so in solution so it is added when you use it.
It also works using lye or washing soda.
I've read elsewhere that if you add Sodium dithionite (also known as Sodium hydrosulfite) it will make the reaction even more effective. 30 grams per liter.
It is short lived, only a couple of days or so in solution so it is added when you use it.
