Ok to zinc plate calipers?

[rcx132]

Is it safe to get calipers zinc plated? Will the plating be ok on the cylinder wall? These ones are ok but as I'm doing the rest of the car.

 

[rcx132]

Note the crummy blue Halfords caliper paint, three coats applied to new calipers, took two years to look like it does now!

 

[optima21]

zinc plating is a standard finish on calipers, with a passivate coating, shouldn't be an issue.

 

[Crater Creator]

I would steer clear of galvanising the inside of the cylinder bore. Quite tight tolerances in those things, you may end up with the piston not fitting.... I'm not sure what kind of surface finish you would get with hot dip galvanising. Plus, the inside of the cylinder doesn't need to be protected from corrosion the same as it's sealed from the elements. Not sure on how you could mask it off but someone more knowledgeable will be along in a moment....

 

[8ob]

Zinc pass is OK for a short term coating but is only microns thick and wont last. I modified some four pot calipers and had them plated, the spare below has been kept in the dry/warm and has lost its newness so I dont rate it. Paint on plate will also fail because it wont key, I would go for blasting for a key and painting.Just a preference

Bob

 

[CompoSimmonite]

I've a pair of professionally reconditioned MG Midget calipers - zinc plated and bore sleeved before stainless pistons and seals etc. They are to be used on a long term, roundtuit, rebuild project (Marlin Roadster) so are just sitting on a shelf at present. Where the zinc has been scuffed whilst in storage they have already started to develop rust so they will be getting paint protection idc. I wonder if stove (or exhaust) paint would be any good ?

 

[rcx132]

Zinc pass is OK for a short term coating but is only microns thick and wont last. I modified some four pot calipers and had them plated, the spare below has been kept in the dry/warm and has lost its newness so I dont rate it. Paint on plate will also fail because it wont key, I would go for blasting for a key and painting.Just a preference

Bob

I've a pair of professionally reconditioned MG Midget calipers - zinc plated and bore sleeved before stainless pistons and seals etc. They are to be used on a long term, roundtuit, rebuild project (Marlin Roadster) so are just sitting on a shelf at present. Where the zinc has been scuffed whilst in storage they have already started to develop rust so they will be getting paint protection idc. I wonder if stove (or exhaust) paint would be any good ?

Yeah, zinc isn't that good. I find it only lasts a couple of years on a daily driver. But when I zinc plate at home I do it three times thicker and I use a stronger passivate. When I get stuff professionally done I go for zinc-nickel which is about five times better. Painting is good but some parts aren't very suited to having a thick later of paint on them, bolts being the best example, but also small clips and brackets.

Bob so does paint not key well to zinc? That's a boo as I had some of my parts zinc plated before painting. But I'm sure my plating textbook says it's ok to paint over zinc.

Ok so are we saying that the zinc won't mess up the brake cylinder bores then?

 

[123hotchef]

i dont know about plating the bores

 

[zeppelin builder]

any body tried blasting and coating with Galvafroid as a base coat ,like a tin of liquid zinc, i suppose you could get them blasted and hot alu sprayed by some of the offshore coating companies ,had a mate got his sidevalve JAP barrels done with this no rust and better heat transfer,think Gemini do it

 

[Crater Creator]

I just bead-blasted then sprayed 2k topcoat direct on my calipers when I did them last year.
Seems to be lasting very well so far.

 

[rcx132]

I just bead-blasted then sprayed 2k topcoat direct on my calipers when I did them last year.
Seems to be lasting very well so far.

View attachment 111675

Gorgeous. Is 2K brake fluid resistant? Guess what... the Halfords caliper paint was not !!

 

[Crater Creator]

It's only as resistant as car bodywork paint, so maybe not 100%, but better than normal rattle-can type.

 

[spacecadet]

Just overhauled my rear brake calipers. These are ATE calipers originally zinc plated, so I went with the same finish. There was no problem with the cylinder bore, zinc will even protect it. I went with 10μm thickness for safety.

I found this guide also useful: http://www.pmbperformance.com/brakehowto.html

 

[Crater Creator]

Just overhauled my rear brake calipers. These are ATE calipers originally zinc plated, so I went with the same finish. There was no problem with the cylinder bore, zinc will even protect it. I went with 10μm thickness for safety.

I found this guide also useful: http://www.pmbperformance.com/brakehowto.html

That's looking beautiful.