I need to paint the underside of my bonnet (big flip front) and want to do it matt black. I will need to brush it on but am not sure what type of paint to use and if I need an undercoat.

use underseal,better protection from flying rocks

Ahhh, yes, good point..... I'll do that then.....

Just make sure its the underseal that sets solid.. you don't want to get covered in the stuff every time you do any work under the bonnet!

Brushable seam sealer would be better than underseal, dries but remains flexible and unlikely to be affected by underbonnet heat

Another suggestion has been blackboard black, as this is quite a big bonnet (Stylus) and underseal will be very heavy ....

I used Sandtex exterior door paint having seen what a good job it did on wood (and having had 3/4 of a tin remaining. It's gloss but looks bloomin excellent on the inside of my tub. I've just painted a couple of ali brackets, which fix the arches on, to hide them too and it's done an excellent job.

spray stone chip applied with a shultz gun will take 5 mins to do dry next day stays flexable to stop (stones chipping) can get in number of colours well white gray black.
brushable seam sealer will take hrs to apply and look crap.
underseal usually stays stiky and will become sticky when warmed by your engine and eany kind of solvent eg petrol will desolve it and it will get every were.

or just get some cellulose satin mat black from local car paint suplys and a 2" brush it will be dry befor u get the last bit covered!

[Edited on 19/7/08 by tootall]

do not put underseal under a bonnet, it will literary melt from the heat and is a fire hazard

Don't use under seal --- it is not petrol or engine cleaner proof and melts with heat --- makes a heck of mess.

Any brush on matt black or matt/satin aerosol will do.

Some underseals can actualy leach through fibre glass, (depends what solvent they contain), and you could end up with black showing through the gel coat, so definately don't use it. Matt black celulose, quick and locost, Ray

Used Blackboard black - worked a treat