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Rust Removal Adventures: Electrolysis, Acid etc


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48 minutes ago, joe90 said:

Timely reading!!!, I have just bought an old cylinder mower which has a fair amount of rust on various parts, I was going to wire brush with angle grinder then hammerite. Would I be better off using above acid stuff? Is there a particular way to get good results?.

 

 

It's easier to just get the remaining paint off and then treat the rust, either by electrolysis or by using phosphoric acid.  I've not used electrolysis, but used to use loads of phosphoric acid when I had a side line in repairing rusty Minis years ago.  Phosphoric acid has the slight advantage that it provides reasonable protection against future rust formation, as the black iron phosphate coating it leaves behind is chemically bonded to the steel, so good in terms of acting as a first stage paint primer.

 

For best results get the paint off, remove the loose stuff, get all traces of oil and grease off, then either brush on or immerse the part in phosphoric acid.

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4 minutes ago, PeterStarck said:

Don't see many rusty cars any more.

True.  It really is amazing how well the bodies last these days.

Last 'rusty' car I had was a Merc C class from about 20 years ago.  Thankfully it was a company car.

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13 minutes ago, joe90 said:

Timely reading!!!, I have just bought an old cylinder mower which has a fair amount of rust on various parts, I was going to wire brush with angle grinder then hammerite. Would I be better off using above acid stuff? Is there a particular way to get good results?.

 

The reason I'm using Diet Coke? It's got phosphoric acid in! Not a lot but it does work albeit more slowly than if concentrated. It's already working on the bearing assembly here after less than a day.

 

Pretty sure a number of descaling products have it in too.

 

If you can afford to wait a couple of months then coat / sink panels in mollases (animal feed shop) and wait. Excellent results if a bit stinky / messy.

 

White vinegar is good.

 

Bilt Hamber Deox-C really is superb I can't rate it highly enough. About £15 per kilo but I've read it might just be citric acid with some additives so that's what I'm going to try. Going to nip to Wilko in a minute and grab some. Ocado do it also I believe.

 

Big fan of good old commercial Jenolite but that might again be phosphoric acid.

 

Electrolysis as per this thread and the tank I made works a treat but as I said is line of sight. Whack an old arc welder on and give the process like 80VDC and big amps and the process is much quicker! Can't emphasise to do it in a well vented space.

 

 

 

 

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Out of interest, as I mentioned above, central heating system descalers contain phosphoric acid. In this case, picked at random, 8% along with citric acid:

 

https://www.toolstation.com/central-heating-descaler-silencer/p43193?

 

I've a 20 year old cleaner from Wickes I might try.

 

I cannot not work. Just time will vary according to concentration.

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I too have an old cylinder mower project I only rediscovered yesterday in the half of the stable I've used over the years. I'll post some pics later. 

 

(Other half of the stable collapsed a short while ago taking out the freebie solar thermal panels I got :( )

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26 minutes ago, PeterStarck said:

Presumably all car bodies are galvanised these days.

 

Some (like mine) are all plastic.  Even the "chassis" of my car is primarily carbon fibre, with an aluminium alloy subframe at either end, where the suspension bits bolt on.

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5 minutes ago, JSHarris said:

 

Some (like mine) are all plastic.  Even the "chassis" of my car is primarily carbon fibre, with an aluminium alloy subframe at either end, where the suspension bits bolt on.

Is that because your car is electric and it's for weight saving.

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11 minutes ago, PeterStarck said:

Is that because your car is electric and it's for weight saving.

 

Partly, yes, and partly because I think BMW are using their electric car model range to explore new materials.  Being electric removes some of the constraints in design, as the drive train is a lot more compact.  This is what the "chassis" of my car looks like, with all the plastic panels removed:

 

image.thumb.png.150b5958304370f8f21b485e09e84131.png

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I'm treating the citric acid as Deox-C. Instructions say a strong solution 4:1, normal solution 19:1:

 

Deox-c_Technical-1.pdf

 

We've put 750g of citric acid in with 3L of water then added half a litre of water to cover everything. So a little over 4:1 but still a strong solution. Cylinder stat is holding everything at 70degC and it's all bubbling away nicely.

 

IMG_20190820_125454878.thumb.jpg.07feed46102304c8c6ac20cfa5a4f6e6.jpg

 

H&S being paramount and to limit

evaporation a cover over the top!

 

IMG_20190820_125507703.thumb.jpg.2d4f70f33d27c27b3daeabd7443b8398.jpg

 

Pulley went in at 13:00hrs.

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After 1 hour:

 

IMG_20190820_134645739.thumb.jpg.45afd3159b96a6a8fc7e94fb8c012b26.jpg

 

The liquid takes on a green tinge, darkening as it loses its efficiency / gets contaminated by the rust coming off. This is just what Deox-C does. Reading the Deox-C instructions again and it contains "detergents". I'm thinking this might be to help lift oily rust. Tempted to put a squirt of Fairy in my little tank.

 

Coming up on 3 hours in there at 70degC:

 

IMG_20190820_155228450.thumb.jpg.15f3c57cac67c9639f7289ad4561e972.jpg

 

I've also thrown in a few equally rusted hand plane blades, an old leather punch, a hammer head etc.

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Just fished this lot out of the heated tank. Pre rinsing but you can see how good it is:

 

IMG_20190820_195616741.thumb.jpg.ee553b5ca4d03f1c4a452d04e9b9f1af.jpg

 

What I recall from using Deox-C was that pretty much everything came out with a black, greasy film on it, that would stain anything. It came off easy enough with a scrub. This citric acid though seems to leave a nice, clean matt grey surface for the most part. I do note the two flat wood bits are a bit black/greasy. 

 

Random bits from a tap to the old, heavily rusted coach screws off the freebie satellite dish. Of course, things like the plane blades would be further wet & dried then kept oiled. To reuse the coach screws outside they would ideally need replating.

 

Happy with the process all in all. 

 

For now I've rinsed the tank out and dumped all the bits in an unheated plastic bucket with the solution where it'll continue to do its thing albeit at a slower pace.

Edited by Onoff
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10 hours ago, JSHarris said:

 

Partly, yes, and partly because I think BMW are using their electric car model range to explore new materials.  Being electric removes some of the constraints in design, as the drive train is a lot more compact.  This is what the "chassis" of my car looks like, with all the plastic panels removed:

 

image.thumb.png.150b5958304370f8f21b485e09e84131.png

a modern A2, cracking wee cars

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On 20/08/2019 at 09:22, SteamyTea said:

True.  It really is amazing how well the bodies last these days.

Last 'rusty' car I had was a Merc C class from about 20 years ago.  Thankfully it was a company car.

 

Apart from the Land Rover Defender of course :D My last "new" Defender (right at the end of production) was rusty straight from the factory ?

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5 minutes ago, Barney12 said:

Apart from the Land Rover Defender of course :D My last "new" Defender (right at the end of production) was rusty straight from the factory ?

Yup..... and they come with special leaking door seals just to keep them authentic........ love them though. 

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5 minutes ago, Barney12 said:

 

Apart from the Land Rover Defender of course :D My last "new" Defender (right at the end of production) was rusty straight from the factory ?

thats because cars have a corrosion protection from bare metal when its welded together of at least 20 different dip treatments before it is finally primed and sealed .then painted 

 but beware any car made in japan etc does not have same treatment as european vehicles 

cos at 3 years old ,the MOt requirements are such that they are basically scrapped --well actually exported to other rhd countries

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4 hours ago, Cpd said:

Yup..... and they come with special leaking door seals just to keep them authentic........ love them though. 

 

Yep, I a self confessed Defender addict. I've tried to kick the habit but just can't. My latest if my best yet. A completely unmolested, factory spec 50th Anniversary with the standard flip metallic paint, 4LTR V8 automatic. It even has the original tape deck :D I'm in love :x

 

Oh and sometimes I start the engine just to listen to the engine ?

 

2019-08-21_16-15-16.thumb.jpg.d37ba5557bd9ceaaef15fde57df383f8.jpg

 

Sorry trashing your thread OP :D 

Edited by Barney12
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@Barney12 Hell man that’s is some serious landrover porn !!!!!!  I rebuilt my first landrover / every nut and bolt when I was 20..... series 2a and now have the knowledge  to pretty much do all the repairs I need from my own humble workshop. Total love affair! Living on an island that does not require an MOT means I can run some pretty old crap and not worry about the madness of an MOT..... though my mainland landy (the grey one) obviously needs to be kept up to spec. The ex Military Police one needs a new canopy now but this is what it looked like a couple of years ago, got a spare axle on the bench at the moment undergoing a FULL rebuild...... again sorry for the thread wobble I will stop NOW ........

6AAF550D-58EA-4E21-A216-309CAF763340.jpeg

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I don't need to bother with an MOT on the mainland any more (> 40 years old) , and £0 historic road tax.

 

Firewood_Rover.jpg.d2388ce7bcbe47e44f5fd0a5cad80055.jpg

That load of firewood had the rear axle down on the stops.  Good job I only travelled about 500 metres loaded like that.

 

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