Converting a metal trough

[Captain Caveman]

I have an old galvanised trough from when the previous owners had a horse/sheep. It's sitting around doing nothing so I thought it would make a great herb container, to put on the patio outside the kitchen - to look nice and easy access
It's 9 foot long and only has a small hole at either end
I don't think it's enough for drainage so planned to put some extra holes in, though only way seems to hammer a nail through the bottom
My missus wants it painted but I'm not sure if it's better left as is
I've cleaned with a pressure wash but want to know how much hassle it would be to get a good finish
As its galvanised, will it need a primer? Does it need special metal and exterior paint, or can I just slap some masonry paint on it?
If I knock holes through does that take away the zinc protection and allow the rust to set in?
Red lead paint gets used for metal but a) it doesn't sound very enviro-friendly and b) I thought its not necessary for galvanised metal

Your ideas please oh wise ishers

[Nick69]

Galvanised metals will just flake off normal water based paints after a few weeks. For a one-coat deal you would have to use something like Hammerite. The other option is Etch Primer then topcoat with whatever paint you want.
Putting holes in the bottom will render the galv' coating usless in that area but if you do the Etch Prime thing, make the holes first and it wont be a problem.

[Captain Caveman]

Cheers Nick
I had read that if galvanised steel has been weathered it will accept a paint onto its surface
Any truth or just best to go for the etch prime? How evil is it on a scale of 1-10?

Any colour recommendations ?

[Nick69]

If you wanted to sand the surface of the steel then paint it (forced weathering) yes it would take but not for long. If we ever need to paint a galv steel we always use an etch prime as you know it will last. Etch prime is not the nicest stuff in the world tbh but you only need the lightest of coats.
Also ask your neighbours/friends if they have a can laying around in the shed instead of buying a can yourself. I find most people do, saves buying CFC disposer ay.

Wipe it down with vinegar to clean it, spray one light coat of etch primer, leave to dry for 48 hours, base coat if you want a nice finish, top coat. If it were me id go with a simple cream colour. It highlights the colours of the plants/flowers well.