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Best rust removal and paint finish for cast components like diff casing
alistairolsen - 21/3/18 at 02:06 PM

I have a diff, drive flanges and shafts to refinish, ideally in gloss black. I cant/dont want to electrolyse these parts for obvious reasons.

In the past I have used bilt hamber products for rust removal, and Ive heard good things about POR15, although this seems to cover a range of products.

What have people used with success to remove rust and protect cast steel and where from?

Thanks

r1_pete - 21/3/18 at 02:19 PM

Media blast and hammerite on the last 3 cars Ive done, also a couple of motorbike frames.

For diffs I wrap the in and out flanges in strips of rag, then put a large jubilee type clip round, never had a problem with ingress, the live mgb axle, I made blanking plates and bolted them on the ends.

40inches - 21/3/18 at 02:35 PM

De-grease, jetwash and rotary wire wheel, then a few coats of Eastwood Spray Grey Paint.

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For Black I used Halfords brush Satin Black engine enamel. The black went on easily without brush marks.
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CosKev3 - 21/3/18 at 04:11 PM

Is the diff stripped?

If it is without doubt the best way to derust is to remove the loose rust then soak it in Bilt Hamber Deox-C water based rust remover

Shot blasting cast iron is not ideal,as it does not remove the rust from the pores.
Needs to be soaked to do a proper job,a acid bath is another way that electroplaters derust cast before plating

[Edited on 21/3/18 by CosKev3]

alistairolsen - 21/3/18 at 04:46 PM

No it's in one piece and I'd prefer to leave it that way really.

I've used doex gel before to good effect, but it was ten years ago so wondered if there was anything better

Cheers

CosKev3 - 21/3/18 at 04:49 PM

Never used the gel,but the powder you mix with water is awesome

StevieB - 21/3/18 at 06:16 PM

quote:
Originally posted by CosKev3
Never used the gel,but the powder you mix with water is awesome


Deox Gel works exactly the same, but has the advantage that is can be used where you can't completely submerse the item. You need to cover it with a plastic sheet (cling film or something) to help it retain moisture over long period - then just scrape the gunk off to leave a clean rust free surface.

But just like the Deox C powder - brilliant.

For alloy parts, I've started using Alubright which is one of the only things I've ever come across which removes all oxidisation from alloy components. A coat of Jet Lac afterwards seals the surface and keeps it looking spangly for longer. Both from Race Glaze.

I'm planning a midget for my next project and will be using an awful lot of the Deox products I suspect!

alistairolsen - 22/3/18 at 04:29 PM

I've ordered a tub of deox gel since it still seems to be a good option (there isnt a new forum favourite magic solution)

Anyone got anything better than hammerite for protecting cast parts? I've never much liked it as it's horrible to apply, doesnt stay glossy and is incompatible with any other paint system.

Cheers

jps - 22/3/18 at 05:30 PM

quote:
Originally posted by alistairolsen
I've ordered a tub of deox gel since it still seems to be a good option (there isnt a new forum favourite magic solution)

Anyone got anything better than hammerite for protecting cast parts? I've never much liked it as it's horrible to apply, doesnt stay glossy and is incompatible with any other paint system.

Cheers


I used some Fortress black metal paint (it was from B&Q) about 2 years ago to paint my hubs. They have just sat in the garage since but they look fine. I'm about to do my gearbox and engine and am just going to use Smoothrite - in silver based on people on here saying it made it easier to spot any oil leaks!

JonBowden - 22/3/18 at 06:04 PM

I can vouch for POR15. I have been impressed with it.
Easy to use and gives a good finish.
The only downside it that it goes mat after prolonged UV exposure but the paint otherwise seems ok