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Painting underneath of the bonnet
Slimy38 - 24/6/25 at 01:50 PM

Hopefully a nice simple one, I want to give the underside of my bonnet a once-over with some black paint. It's either roller or brush because of the rough surface, and as you might expect I'm not aiming for a showroom finish. Any recommendations on type of paint and/or where to get it from?

jacko - 24/6/25 at 02:34 PM

Yes fire proof paint is my recommendation say like you paint chimneys with if you have to paint it

nick205 - 24/6/25 at 02:45 PM

I can't make any recommendations, but jacko's fireproof seems one pretty reasonable.

Out of curiosity, why are you wanting to paint the underside of the bonnet?

Slimy38 - 24/6/25 at 03:03 PM

quote:
Originally posted by nick205
I can't make any recommendations, but jacko's fireproof seems one pretty reasonable.

Out of curiosity, why are you wanting to paint the underside of the bonnet?


There's a few reasons. First, I quite like the look of it when I see other cars open at kit car shows and the bonnet is painted. The second is where I've attached my wheel arches, the fibreglass and metal are different colours to the base bonnet so it's just to blend them altogether;



The last one is that the bonnet is very slightly transparent in certain areas. It's just the thickness of the build-up (or lack thereof) but it makes things look patchy, again when it's open.

Slimy38 - 24/6/25 at 03:12 PM

quote:
Originally posted by jacko
Yes fire proof paint is my recommendation say like you paint chimneys with if you have to paint it


Sounds quite reasonable, I'll give it a go. Thanks.

nick205 - 24/6/25 at 03:14 PM

Understood and thanks for explaining.

My MK Indy bonnet didn't had 4 bonnet catches rivetted to it. Aside from that the layup was thick enough all over.

mcerd1 - 25/6/25 at 12:15 PM

Painting the rear side of GRP is always a good idea - it helps stop any rough/loose fibers from ending up in your hands

Years ago someone recommended just using a decent household exterior gloss paint, its worked great on other parts of mine (as a bonus you can sometimes get discount paint if it's in a colour that no-one if ever likely to paint a house)

but something a bit more heat resistant sounds like a good idea for the engine bay

bi22le - 25/6/25 at 02:33 PM

I dont know what paint is used to paint the underside of my bonnet black but I do know that now it is painted black you cant see the dirt!

This is good BUT under the bonnet does get dirty, the end result is when you are not careful you get covered in grime by just rubbing slightly against it (like I did and ended up looking like I had climbed up an exhaust pipe!).

Slimy38 - 27/6/25 at 02:52 PM

quote:
Originally posted by bi22le
I dont know what paint is used to paint the underside of my bonnet black but I do know that now it is painted black you cant see the dirt!

This is good BUT under the bonnet does get dirty, the end result is when you are not careful you get covered in grime by just rubbing slightly against it (like I did and ended up looking like I had climbed up an exhaust pipe!).


That's an interesting thought. I have a post-IVA task to fill in the arches of my car (full body rather than a seven) but if you're saying a seven still gets muck under the bonnet perhaps I should just accept it as inevitable and remember to hose things down more often?