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[omega2018]

ive got 2 new front discs to fit.  dont want them to rust like the insides of the old ones so im thinking of spray painting them with hycote very temp paint. 

question is do I spray the whole disk or am i supposed to mask off the contact area?  masking will be a chore plus i suspect it is the areas just on the edge of the contact zone that start the rust so they need the paint most.  the v high temp paint is not oil based so should just scrape off the contact area in first use and not contaminate the pads shouldn't it? assuming i spray it lightly?

i see the few pre painted discs like the black high gloss mtecs come painted all over
. 
doubtless that is some fancy special coating.

if the advice is absolutely not to spray the contact area i suppose  i could spray it and then remove it with some temporary fine sandpaper between the pads and disc for a few spins.

[Nick W]

I wouldn't paint the contact areas at all, just the edges and the mounting bell.
Actually, if I were that concerned about discs appearance, I would buy coated ones and forget about them.
The Pagid discs on the rear of my car are only just starting to discolour after 3 years, which is good enough for me

[omega2018]

thanks my rears are fine it is just the insides of the front. seems to be a common problem and defo not cosmetic.  being inboard cosmetic appearance would not be an issue but anyway im not sure you can see anything on a front disc except the contact area. 

[chrisgixer]

I set mine up placed on an old wheel bearing on a bench spin the disc slowly as required and spray the vented edges, then the centres.

Some very slight over spray on the contact area won't hurt.

...and it's nothing at all to do with appearance. As said the inboard outer edge of the front discs will rust away on the swept area otherwise. Limiting the life of the discs.

Worth buying pre painted though, although the Gm front axle set is hard to beat on price, but are not painted.

[05omegav6]

Painted or not seems to be down to whoever made the discs... Vectra kits are painted the way Chris suggests, Mercedes disc are fully painted and the pads soon clear the contact area

[Marks DTM Calib]

Yes, I don't see an issue, degrease well with thinners or similar and then slap some high temperature paint on and job done.

[VXL V6]

Have taken to painting mine now for the same reasons.

The Pagid discs fitted to Mrs VXL's Alhambra were coated already (no need to degrease according to the instructions) and they are holding up so far.

[TheBoy]

I set mine up placed on an old wheel bearing on a bench spin the disc slowly as required and spray the vented edges, then the centres.

Some very slight over spray on the contact area won't hurt.

...and it's nothing at all to do with appearance. As said the inboard outer edge of the front discs will rust away on the swept area otherwise. Limiting the life of the discs.

Worth buying pre painted though, although the Gm front axle set is hard to beat on price, but are not painted.

Have you tried painting on GM discs, and if so, did it cure the inner face problem?

[chrisgixer]

I set mine up placed on an old wheel bearing on a bench spin the disc slowly as required and spray the vented edges, then the centres.

Some very slight over spray on the contact area won't hurt.

...and it's nothing at all to do with appearance. As said the inboard outer edge of the front discs will rust away on the swept area otherwise. Limiting the life of the discs.

Worth buying pre painted though, although the Gm front axle set is hard to beat on price, but are not painted.

Have you tried painting on GM discs, and if so, did it cure the inner face problem?

Yes, but I swapped them for ebc and painted those as well. The ebc have reached the end of their wear, and are in danger of going on past the minimum wear point without encountering the judder and loss of performance that the rust on the outer edge of the inboard face induces on gm discs.

Sadly not the answer your looking for.


But... To be more relevant....the gm discs did go rusty, but only did so after a year. I'm fairly certain that year, at my mileage at least, is enough to wear the discs out before the rusty inner edge gets to them. There by getting more mileage out of the discs.


I can assure you its not an appearance thing, in that I would prefer to keep the nice shiny finish of the originals, if at all possible. Shame they don't do a clear heat proof lacquer.
Having said that, they grey paint is far better looking than shitty rust brown.

Try it. It can't possibly do any harm, and can only add life to the discs. As the rust gets them before they wear out ime.

[TheBoy]

Ta. The next set I'll do. I just didn't want to be gay if it didn't help.

[chrisgixer]

Ta. The next set I'll do. I just didn't want to be gay if it didn't help.

Too late

[chrisgixer]

Ps. Don't use the stuff Halfords sell. Its sh..  ...not very good.


...well, assuming the fact it washes off with brake cleaner is bad. Or maybe that's unfair. Brake cleaner is quite fierce, I suppose.

[05omegav6]

Ps. Don't use the stuff Halfords sell. Its sh..  ...not very good.


...well, assuming the fact it washes off with brake cleaner is bad. Or maybe that's unfair. Brake cleaner is quite fierce, I suppose.

Doesn't work on tree sap/baked bird poo...

[Kevin Wood]

Ps. Don't use the stuff Halfords sell. Its sh..  ...not very good.

Seconded. "High temperature enamel". Painted the cam cover on the Westfield with that. First time it got hot, half of the paint fell off. Don't think it's going to be much use on a brake disk!

[05omegav6]

The paint on both the GM discs for the Vectra C and Mercedes discs are painted with a fine grey paint which does rub off the disc with brake cleaner and a bit of elbow grease, almost looks like primer