View Full Version : Which engine paint?

15-09-2007, 01:00 AM
I have several cast aluminium components which have been grit blasted clean for the best possible surface for painting. They include a cylinder head and an inlet manifold.

The paint I need must be:

High temperature but not requiring curing in an oven
Solvent proof
A good match to the appearance of cast aluminium

Finding a suitable paint is more difficult that you'd believe.

The cylinder head has steel valve seats and guides pressed into the aluminum so I cannot use paint which requires very high temp oven curing. Powder coating's not suitable for the head either.

The brands of paint I have found (and bought a few cans of too) fulfill some but not all of the criteria on the list. Most important are high temp and solvent proof.

I thought I'd finally found the righ stuff in some Sperex paint specifically designed for cylinder heads, but it's not solvent proof despite the label saying so. Even after curing at room temperature (as per the instructions), brake cleaner (xylene) made the paint fizz and slide off :mad: :wall:

Paints tried so far:

Eastwood Detail Grey (not solvent or heat proof)
Sperex Engine Enamel (not solvent proof)

I have an engine to put back together and am fed up going around in circles trying to find suitable paint. Sorry to grovel, but someone please help me out before I go mad! :wall:

Mr yella
18-09-2007, 09:06 PM
Ive used a ICI TURBO 2 pack commercial paint on my rocker covers .
Been solid for 2 years .

19-09-2007, 01:30 PM
itd be nice to find some paint that is brake cleaner proof, but in all fairness if you are spraying a cylinder head and intake then why use brake cleaner on those components?

i just use halfords hi-temp engine paint in silver, came out really nice, and i dont have any probs keeping my cylinder head, or block for that matter clean

27-09-2007, 12:34 AM
One example: I might use brake cleaner or similar solvent (such as carb cleaner) to diagose possible vacuum leaks. You spray the carb cleaner at the suspected source of the leak and if the engine speed rises then you know you've hit gold.

I mentioned brake cleaner as an example but of course there's also petrol and other solvents.

I have tried the Halfords Aluminium paint. Nice finish but even after curing in an oven (gently raising the temperature from 25 degrees to 200 degrees over two hours) the paint scraped off with a fingernail. Not tried the solvent test yet though.

The search goes on! :lol:

30-09-2007, 06:42 PM
have you tried stove paint?

Mr Concours
01-10-2007, 10:55 AM
Have you had a look at Frosts?They do loads of stuff you never knew you needed!Sometimes a little on the pricey side, somethings can be found a lot cheaper in the States (hint,hint) www.frost.co.uk

gti mad man
04-10-2007, 09:40 AM
ive tried
1)halfords sh*t
2)caliper paint youd need loads
3)hamerite burns off

04-10-2007, 02:22 PM
use the frosts engine paint, i have it all over mine, just take a look at my engine and you will see what its like, even now, a little warm water and all the crap just runs off, same with the chassis , itsc oated in por15 chassis paint then over coated in sterling silver paint.

17-10-2007, 12:38 PM
if you're painting aluminium don't you have to use an etching primer first?

17-10-2007, 02:50 PM
Simoniz Five Wheel Silver paint fits the bill.

Mr Concours
17-10-2007, 10:49 PM
if you're painting aluminium don't you have to use an etching primer first?

Not to my knowledge.

Not sure I'd trust Simoniz Wheel paint on an engine,I don't think it would stand the heat of an engine (no pun intended)

Mr yella
18-10-2007, 06:55 AM
Etch primer needs to be applied to ali to give it a secure base for the top coat .#
Etch has acid properties which "eats" into the ali to help it stick , normal primer would flake off .....

22-10-2007, 07:46 PM
Etch has acid properties which "eats" into the ali to help it stick , normal primer would flake off .....
I have a blasting cabinet. All ally components will be grit blasted, which gives the best surface key for paint.

I won't use an etch primer here because (a) I don't think it's needed what with the rough surface and (b) I'd have to find a high-temperature etch primer which AFAIK don't exist.

Not sure I'd trust Simoniz Wheel paint on an engine,I don't think it would stand the heat of an engine (no pun intended)
I painted a test piece (grit blasted aluminium thermostat housing, entirely typical of the paints intended use) and baked it in the oven at 250 degrees for several hours.

Even at full temperature the paint hadn't softened and when cold I swear it was harder. Actually, it's rock hard.

I'm going to trust this stuff. I have tested about five different products and this is the only one to pass.

Mr yella
22-10-2007, 08:37 PM
I used just a normal etch primer on my 106 gti rockers and i have had no problems with bubbling or flaking in the 3 yrs its been done .....
And they get very hot ......:thumb:

22-10-2007, 09:31 PM
Very interesting :) I assumed any etch primer not labelled high-temp wouldn't stand up to hot cylinder head temperatures.

I have to admit I am very surprised at how good that wheel silver is. More solvent resistant than Simoniz's "solvent resistant" paints and more temperature proof than Halfrauds's "high temperature" paint :lol:

As an aside, if anyone wants a silver paint that is a staggering good match for rough-cast ally, then try the Halfraud's stuff. I still have the test piece I did from that and it just doesn't look painted at all :lol:

02-11-2007, 11:44 AM
hows this quest going?

10-02-2008, 05:44 PM
hows this quest going?
I'm sticking with the Simoniz 5 Wheel Silver.

Since starting this thread I have tested a few other products in the same way: spray, air cure, test with brake cleaner, bake (gently raising temperature to 150 deg C), air cool, test with brake cleaner.

Halfords Brake Caliper Paint resisted the brake cleaner after the paint had air cured but was rubbish after it'd been baked. Hammerite Smooth Silver was also good after air curing but the paint went very soft when baked.

Interestingly, Simoniz (Hols Lloyd International) have changed the formulation of the Wheel Silver to an acrylic-based mix (to comply with nannying and stupid European legislation). Unable to find cans of the old stuff, I tested the new stuff and expected it to be crap. Turns out it's at least as good as the old formulation, perhaps even a bit better.

It'd be nice if I could find a similarly tough satin or matt lacquer just to add a touch of additional protection for the basecoat. It is designed to be used with a lacquer afterall.

10-02-2008, 05:51 PM

a thread made by myself on what is required and reccomended for painting ally engines.

you do need to etch primer the surface, regardless of wether you've grit blasted it etc.



10-02-2008, 05:56 PM
Recommend to me a high-temperature acid etch primer :)

13-02-2008, 11:19 AM
plasticoat hot paint! 650c very good stuff! halfords superstore sell it!

23-02-2008, 05:00 PM
im gonna be trying some stove paint on my engine soon

23-02-2008, 05:47 PM
If the prep work is done properly and you use a decent etching primer then normal two pac car paint is fine.

Mine have been done for 3 years now and they are still holding out well considering the amount of times my engine has been pulled appart :D


08-11-2012, 02:20 AM
^^ that is pure detailing/petrolhead porn!!!
P2P you should be banned :)