upgrading front discs

Suspension; Gearbox, Clutch and Driveshafts; Brakes; Steering; Throttle and clutch cable issues

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mr alpine92
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Re: upgrading front discs

Post by mr alpine92 » Sat Nov 07, 2015 1:22 pm

james butler wrote:that looks well nice how did you clean up the calipers so well?
i need to do mine next year
i like to say buying second hand brakes make sure they pass pressure test mine failed :-( ,so got them fully refurbished like new,safety fist bro always,i had them done here
http://www.brakecaliperspecialists.uk/b ... rbishment/
it work out, with new discs, pipes, calipers, blots,and refurbished that cost £330,and i allso done me back drum brakes, hand brake cables, and pipes,so all new brakes all round,so all in all about £500,and for spacers i need 12mm ones, with 35-40 Fred bolts,and my next job, is to do the ball joints, wheel bearing, disc backing plate, and new wishbone arms, and new bushes,which i got setting here waiting to go on, ;-) chris,



marcus
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Re: upgrading front discs

Post by marcus » Sat Nov 07, 2015 5:34 pm

There's an electrolytic method of de-rusting metal, using a battery charger (old school non automatic variety) and some common or garden variety of chemical the name of which eludes me at present.

I did this a few years ago on mine and the results were astonishing, sadly, because I mis-adjusted the relay rod, I got serious brake bind to the point the front discs glowed bright red - why didn't I stop before then I hear you ask, well I was on a dual carriageway without a hard shoulder and knew there was a service station a bit further on. What amazed me was that the clutch didn't slip, given it was having to fight the brakes.

Anyway, the high temperature lacquer I'd applied to the calipers burned off, so now they look as rubbish as ever. :(

I'll see if I can dig out details of the method, it was fairly straightforward if a bit fiddly


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bengould
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Re: upgrading front discs

Post by bengould » Sat Nov 07, 2015 6:40 pm

Soda crystals
Water
Plastic bucket
Scrap steel for cathode
Battery charger

Mix soda crystals in water.
Connect charger +ve to part to be "cleaned"
Connect charger -ve to scrap steel.
Put both in the soda bath in such a way that they can NOT touch.
Turn charger on and leave for anywhere between 12-24hrs.
Scrub off flakey bits with a wire brush.

This works on a line of sight principle so bits or your part that cannot directly see the cathode will not get cleaned. Turn the part round half way through and it will then ensure both sides get even treatment. Or make your cathode from a flat sheet of steel and bend it round the inside of your bucket, then suspend the part in the middle.

Worth noting, do not put the charger terminals in the water. Hang your part on a piece of steel wire and make your cathode so that it sits above the water level.

After you have done this your clean part will be black and not shiny like above. If this is the look you are after it just takes a bit more effort with a wire brush when it is dry.

Any questions Google electrolytic rust removal. There are some extremely detailed guides on the web.

Ben.


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marcus
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Re: upgrading front discs

Post by marcus » Sat Nov 07, 2015 6:51 pm

Thanks bengould, you saved me a job there!


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james butler
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Re: upgrading front discs

Post by james butler » Sat Nov 07, 2015 8:05 pm

better than that get some of this stuff
Image

stick your rusty stuff in a bucket with the patio cleaner for a couple of days and agitate it regularly and the rust simply disapears.

Image
Image
doesnt seem to cause any harm to the steel but obviously if its too far gone its worth replacing it anyway.


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james butler
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Re: upgrading front discs

Post by james butler » Sat Nov 07, 2015 8:09 pm

word of warning though it takes paint off too.

the only problem with the battery charger method is i was led to believe toxic gas is released while its working/ derusting?
something like that. :scratch:
using the patio cleaner i found a lot easier plus once your parts are clean i just wash them off with water then blow dry and paint imediately as the metal has nothing protecting it from rusting up again so painting ASAP is a must.


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mr alpine92
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Re: upgrading front discs

Post by mr alpine92 » Sat Nov 07, 2015 10:44 pm

james butler wrote:word of warning though it takes paint off too.

the only problem with the battery charger method is i was led to believe toxic gas is released while its working/ derusting?
something like that. :scratch:
using the patio cleaner i found a lot easier plus once your parts are clean i just wash them off with water then blow dry and paint imediately as the metal has nothing protecting it from rusting up again so painting ASAP is a must.
i saw a video were a guy used, water and white vinegar, mix to giver, after removing the rust, he added the vinegar water to the metal and let it dry out, it look rusty colour,then he just wash that off, with just water the metal was black underneath, as the vinegar water kills the rust virus in the metal,which make the metal black and the it ready for primer,
chris



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james butler
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Re: upgrading front discs

Post by james butler » Sun Nov 08, 2015 7:58 pm

trouble is your still using water in the process which leads to rust

below is an extract from wikipedia

"Rust is another name for iron oxide, which occurs when iron or an alloy that contains iron, like steel, is exposed to oxygen and moisture for a long period of time. Over time, the oxygen combines with the metal at an atomic level, forming a new compound called an oxide and weakening the bonds of the metal itself. Although some people refer to rust generally as "oxidation", that term is much more general; although rust forms when iron undergoes oxidation, not all oxidation forms rust. Only iron or alloys that contain iron can rust, but other metals can corrode in similar ways.

The main catalyst for the rusting process is water. Iron or steel structures might appear to be solid, but water molecules can penetrate the microscopic pits and cracks in any exposed metal. The hydrogen atoms present in water molecules can combine with other elements to form acids, which will eventually cause more metal to be exposed. If chloride ions are present, as is the case with saltwater, the corrosion is likely to occur more quickly. Meanwhile, the oxygen atoms combine with metallic atoms to form the destructive oxide compound. As the atoms combine, they weaken the metal, making the structure brittle and crumbly.

Oxidation of iron
When impure (cast) iron is in contact with water, oxygen, other strong oxidants, or acids, it rusts. If salt is present, for example in seawater or salt spray, the iron tends to rust more quickly, as a result of electrochemical reactions. Iron metal is relatively unaffected by pure water or by dry oxygen. As with other metals, like aluminium, a tightly adhering oxide coating, a passivation layer, protects the bulk iron from further oxidation. The conversion of the passivating ferrous oxide layer to rust results from the combined action of two agents, usually oxygen and water.

Other degrading solutions are sulfur dioxide in water and carbon dioxide in water. Under these corrosive conditions, iron hydroxide species are formed. Unlike ferrous oxides, the hydroxides do not adhere to the bulk metal. As they form and flake off from the surface, fresh iron is exposed, and the corrosion process continues until either all of the iron is consumed or all of the oxygen, water, carbon dioxide, or sulfur dioxide in the system are removed or consumed.

When iron rusts, the oxides take up more volume than the original metal; this expansion can generate enormous forces, damaging structures made with iron"


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mark1gls
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Re: upgrading front discs

Post by mark1gls » Mon Nov 09, 2015 12:39 pm

Everything you ever wanted to know about rust in the post above, my wife thought I was the only person obsessed with rust and it's removal/prevention etc but it seems I'm not alone...... :good:


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RoccoJimbo
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Re: upgrading front discs

Post by RoccoJimbo » Thu Jul 09, 2020 8:37 pm

Can anybody point in the right direction for which year of corsa the calipers,carriers & flexis can be obrained from for this mod. Also, where can the bolts be bought from that are used for this upgrade? I've seen that they are M10 but what is the length required etc?
The main thing that stops me performing this mod is locating the correct bolts. I think the main components are easy to find/purchase.
With thanks


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james butler
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Re: upgrading front discs

Post by james butler » Sat Jul 11, 2020 5:00 pm

you could always just make some spacer tubes and use the origenal bolts
thats what i plan to do


I dont mind project cars but I HATE SANDING!!!