Painting metal

I know this is woodwork forums but...I need to paint (matt black) the heads of several large cup head bolts holding some outdoor chairs (kept on verandah) together. I don't want the paint to chip or flake off for a long time. Would powder coating be far and away the best method in this situation? Cost is not an issue. Otherwise, which paints does anyone think would be best? Something spray on would be convenient.

I'm thinking of using gal bolts so the rest of the bolt doesn't rust. Should I grind the gal coating off the head before starting.

Powder coating would definitely be a superior solution but you may balk at the cost.

If you wanted to go for a cheaper but still effective solution then I would definitely go for galvanised bolts but leave the galv on and use an etch primer on the galvanising followed by an epoxy enamel (booth sprays) and probably use several coats of the enamel.

Thanks Bob. I was hoping the coaters might do it for $10 or so for me but I'm probably dreaming. I'll post the quote for interest.

If using gal bolts, first make sure to degrease the bits you want to paint,(new gal bolts tend to have an oily coating) then use an etch primer or some magic stuff put out by White Knight called Grip-Lock Primer. It's a waterbased paint which allows you to paint substrate with any paint you like. I use it under spray epoxy on fibreglass and under hammertone on old, slightly rusty metal. The key to a long lasting finish is a good undercoat

Thanks Graeme. Really appreciate these tips.

I you are prepared to wait until the powder coater is doing a run of the colour you want, you may find adding several bolts might not cost you too much

Should the powder coating not come to pass - go with the degreased gal bolts but first do a dip and dry in Penetrol before you paint - this stuff is truly great and what is more it is Australian and not even made in China.

No connections with the Flood Co other than a long time happy user.

Thanks. Penetrol is certainly sticky stuff, and I have mixed it with powders/concrete colours in the past for finishing metal. But would you put etching primer over it?

I have not done so and have experienced no problems. However, that said, give the Flood company a call on their help line and ask the experts their take on it.

Good on you mate