13 replies to this topic

[RawlinsGTR]

Hello!

So I'm painting my engine and all that stuff in the engine bay, and I want to paint the heads of the bolts (some black, some silver) so that they look nice to.

I'm wondering - what type of paint is the best paint to use for this? Normal halfords spray paint and stuff isn't really very hard wearing, and I know that as soon as you go to do the bolts up, the paint chips and stuff.

Should I use brush on paint, or spray paint? I don't have an air gun or anything like that, so if it was spray paint, it would need to be rattle cans.

Any suggestions are appreciated,

Cheers,

Simon.

[rally515]

Chromed bolts ?

[lapider]

i think whatever you do its likely to come off when you tighten them down. get them on a wire wheel, they look best then in my oppinion. you can get chrome caps for head studs which slip over, or i have seen a yellow pick up where he had hand polished every single nut an bolt in the engine bay. so much effort.

[james962]

I wouldn't bother painting the bolt heads. If you want it to look nice, buy new bolts.

[Artful Dodger]

Paint them after!! Hand paint them with just hammerite etc:P

Or clean metal with a smear of grease

[RawlinsGTR]

Hmm, cheers guys.

I want to paint the ones that were rusty, to stop them rusting again, that's the main reason really.

Still!

[rubinio]

if you really must then wire wheel and oil/grease them up, painted bolt heads look awful IMHO

you could metal black them with a kit such as the one from frost afterwards, i wouldnt oil black them because that would heat treat them, but the frost kit is a cold process so should be ok, works quite well as well as long as the metal is clean and bright before you start the process

Edited by rubinio, 24 April 2013 - 05:28 PM.

[RawlinsGTR]

Cheers rubinio.

It's strange, because I've seen so many pictures of engine bays where there are black bolts everywhere, I just thought it was a common thing.

Seems not!

[corrado vr6]

You could have them anodised or zinc or nickel plated, most chroming places have a minimum order of £40 so get as many bolts, nuts, washers etc as you can as they will do a big batch of bolts etc for that price

Edited by corrado vr6, 24 April 2013 - 07:09 PM.

[rally515]

You could have them anodised or zinc or nickel plated, most chroming places have a minimum order of £40 so get as many bolts, nuts, washers etc as you can as they will do a big batch of bolts etc for that price

Correct me if im wrong but isnt anodising for ally,titanium & such materials ?
dont think you can anodise steel :s

[samsfern]

Used to see painted bolt heads a lot when i was in the classic car game, and always thought the looked awful and tatty. When i detailed the engine bay of a near concourse austin healey 3000 trailor queen, i removed each bolt, used the wire wheel to clean them up, then polished the heads up to a mirror shine using various polishing wheels and compounds. The ones i didnt want to disturb were done with careful use of a dremel and some polishing wheels and compounds.

Edited by samsfern, 24 April 2013 - 08:12 PM.

[RawlinsGTR]

Cheers Sam, but polishing them doesn't stop rust though does it?

[tiger99]

DO NOT PLATE THE BOLTS! This is very important for safety, as when high tensile steel is plated, the dreaded hydrogen embrittlement is inevitable.

You can buy bolts already plated by either zinc, nickel or possibly cadmium, however cadmium is toxic in certain circumstances (which you will not usually come across in a Mini) so it is almost unobtainable now. Properly manufactured bolts are plated in a way which is safe, often by using a mechanical process, DIY plated bolts, or those done by your local chrome plating company certainly will not be.

All processes using aqueous liquids may potentially give rise to hydrogen embrittlement, so if you are using a chemical blacking process it is very important to check that it is harmless. You should be able to find one that is ok, and a black finish can look ok. I would advise a long bake (say an hour) in your domestic oven at its maximum temperature, immediately after blacking, as an added precaution.

Oh, and although it has been said here many times, I will say it again, DO NOT USE STAINLESS BOLTS except on minor items which are not stressed significantly. Most grades have insufficient tensile strength, and none of the available grades has sufficient fatigue strength to replace a standard 8.8 bolt safely.

In the extreme case that, as a very last resort, you must have a plated bolt for some very special reason, you MUST go to a plating company that does work on something like aircraft components, and have them do it using a proper approved process.

If you have even seen a chrome plated bumper, especially on older cars, which has cracked or broken around the bolt holes, not due to an accident, that is a typical example of the effects of hydrogen embrittlement. Bumpers are mild steel, it is far worse on high tensile.

[lapider]

Used to see painted bolt heads a lot when i was in the classic car game, and always thought the looked awful and tatty. When i detailed the engine bay of a near concourse austin healey 3000 trailor queen, i removed each bolt, used the wire wheel to clean them up, then polished the heads up to a mirror shine using various polishing wheels and compounds. The ones i didnt want to disturb were done with careful use of a dremel and some polishing wheels and compounds.

i met a guy with a custom yellow pick up at a show in cardiff. when i first looked at his engine bay it looked really good but i thought he had just replaced everything with cheap chrome parts, then i looked closer and realised he had hand polished every steel component in the engine bay. some serious dedication and time went in to it.