Remove rust (without using abrasives).

[Little Dog]

Molasses (large components)

Horse food supplement from equestrian suppliers:

Probably the option if you have young children, are concerned about electricity in water or want to use environmentally friendly rust removal methods. Mix 20% molasses in warm water:

Place components in a plastic tray The smaller shaft is quite badly rusted and the larger one has a surface rust and a patch of flaky rust:

Cover with molasses water mix:

Be patient:

The speed of rust removal is temperature dependent. As it is cold I will check progress next week.

The mix will last months and convert many components.

 

[cheechy]

Reading this one with great interest. Isnt science great?

Brake caliper prep for painting....I usually just brush down and paint with rust oleum but this does look much more efficient. Any gotchas for calipers and any of these chemicals? Particularly interested in the comment around aluminium contact.

 

[Little Dog]

Reading this one with great interest. Isnt science great?

Brake caliper prep for painting....I usually just brush down and paint with rust oleum but this does look much more efficient. Any gotchas for calipers and any of these chemicals? Particularly interested in the comment around aluminium contact.

I cleaned up a pair of Mini brake calipers recently using electrolytic rust conversion. Just make up a length of brake pipe and fit to the caliper; close it or connect to it. Clean up nicely.

Probably the same for Molasses but takes a while to convert at this time of year.

 

[Vorsprung durch Technik]

Molasses (large components)

Horse food supplement from equestrian suppliers:

Probably the option if you have young children, are concerned about electricity in water or want to use environmentally friendly rust removal methods. Mix 20% molasses in warm water:

Place components in a plastic tray The smaller shaft is quite badly rusted and the larger one has a surface rust and a patch of flaky rust:

Cover with molasses water mix:

Be patient:

The speed of rust removal is temperature dependent. As it is cold I will check progress next week.

The mix will last months and convert many components.

Yep, i too can attest to this wonderful method of rust removal. When i bought mine at the local Equestrian centre they were quite amused at what i was going to use it for. Lol

 

[Little Dog]

A quick update on the progress with Molasses rust conversion. I'm not expecting the process to have finished because the rust was crusted and it has been too cold for the chemistry to work effectively. Fresh from the mix:

Hosed and wire brushed:

About 80% gone, back into the mix and with higher temperatures throughout next week I should have the shafts ready for a weekend painting session.

 

[cheechy]

Looking good any issues with horses?

 

[Little Dog]

Looking good any issues with horses?

Nope, take an Iron Horse to eat those shafts.

 

[B4Andra]

Great thread, interested in what you will do to plate these?

 

[Little Dog]

Great thread, interested in what you will do to plate these?

Plating would mess up the tolerances on the splines. These will be masked and painted.

Going to have fun plating the CV joints on the outside only, I put them through electrolytic rust conversion.

 

[B4Andra]

I didn't explain myself! I'm not talking just about the drive shafts but your other bits and bobs, the reason I ask is my big "It's In Here" box, full of all VAG used nuts and bolts. The reason it's called the "It's in here" box is that without fail, any missing bolt I have had to replace in the last 5 or so years, has been in that tub.

However, the bolts in there are in a sorry state, and I'd love to just dip them over-night in something, come back and they all be shiny and new, but then I'd like to, en-masse, plate them so they stay shiny and new.

 

[Little Dog]

I didn't explain myself! I'm not talking just about the drive shafts but your other bits and bobs, the reason I ask is my big "It's In Here" box, full of all VAG used nuts and bolts. The reason it's called the "It's in here" box is that without fail, any missing bolt I have had to replace in the last 5 or so years, has been in that tub.

However, the bolts in there are in a sorry state, and I'd love to just dip them over-night in something, come back and they all be shiny and new, but then I'd like to, en-masse, plate them so they stay shiny and new.

Like this https://www.a2oc.net/community/index.php?threads/zinc-plate.35181/

I have clear, black and yellow passivate to replicate the original finish.

 

[Little Dog]

Two days of warm weather and:

There were just a few flecks of rust left that I would have just filed of if I wanted to paint today. Nope road testing the A2 so they have gone back in. Judging by the activity in the now warm mixture I think all rust gone tomorrow

 

[B4Andra]

Fantastic stuff, besides from one of them looking like the surface of the moon Easily fixed though. Good thread!

 

[Little Dog]

thank you, rust removal unfortunately does not replace rusted metal. Therefore, yes it looks like the surface of the moon. However there is no rust.
The good news is paint sticks very well to the cratered surface.

 

[TFG]

Inspired by @philward 's scribings, I purchased a zinc/nickel plating kit from Gateros (something I've looked at many times over the past couple of years, but never flexed the card for), grabbed a couple of brackets from my A2 as a learning subject...

....and set to. First off, getting them prep'd. Brushed of the crud and flaky rust, then into my version of 'The Skanky Bucket'

Never mind chemistry; to me, this is alchemy. As someone who never even did CSE chemistry, it's a Whole New World. I wouldn't be doing this without your guidance Phil. Many, many thanks

A couple of queries: What effect does the amount/concentration of oxy-cleaner have on the process? What about the voltage/current applied? My old battery charger barely registers any current draw, yet there's been a steady stream of bubbles coming off of these brackets for many hours now and clean metal is magically emerging from the filth. Whilst that is going on, I'm reading up on the ins-and-outs of the plating process......

 

[Little Dog]

Question 1; I don’t know but two scoops in my tub does the job.

Observation 1; yep that’s right very little current and the rust goes.

Two things, make sure the anode and cathode can’t touch under any circumstances, the current that charger can deliver will cause a fire.

If the bubbling stops and you still have rust clean the sacrificial anode.

Phil

 

[TFG]

Related, but slightly off at a tangent (and I don't want to divert this thread from the original topic): @philward - how do you get the rubber bit (harmonic damper?) off of the shorter driveshaft?

 

[TFG]

As an adjunct to this thread, is there a thin coating or finish (other than electroplating) that can be applied to exposed parts like suspension and driveshafts to protect them from corrosion, where paint isn't a suitable solution? I'm thinking about threads, mating faces etc.

 

[Little Dog]

Related, but slightly off at a tangent (and I don't want to divert this thread from the original topic): @philward - how do you get the rubber bit (harmonic damper?) off of the shorter driveshaft?

Sorry TFG I missed this request. I didn’t take the damper off. Those shafts are from a MK2 golf.
I have two steel components with crimped rubber parts in molasses at the moment. The rubber is holding out fine.

 

[Little Dog]

As an adjunct to this thread, is there a thin coating or finish (other than electroplating) that can be applied to exposed parts like suspension and driveshafts to protect them from corrosion, where paint isn't a suitable solution? I'm thinking about threads, mating faces etc.

I use ACF 50, preserves metal well proving it is protected from spray or abrasion. Also use it to protect rust converted parts if I don’t have time to paint or plate.
If subject to spray / mild abrasion Waxoyl does a good job if it is given time to set.